Clean up some styles.

Adjust margin spacing.
Rework sidenote spacing and TOC.
2020-07-15 13:56:03 -07:00 · 2020-07-15 13:18:34 -07:00 · 2020-07-15 13:13:47 -07:00 · 2020-06-30 22:15:22 -07:00 · 2020-06-30 21:31:16 -07:00 · 2020-06-30 21:22:19 -07:00
84 changed files with 5123 additions and 156 deletions
--- a/.drone.yml
+++ b/.drone.yml
@@ -10,7 +10,7 @@ steps:
  - name: test-compiler
    image: archlinux
    commands:
-    - pacman -Sy cmake gcc make llvm bison flex gettext --noconfirm
+    - pacman -Sy cmake gcc make llvm bison flex gettext libffi --noconfirm
    - cd code/compiler
    - ./test.sh
  - name: build-live
@@ -22,17 +22,17 @@ steps:
      path: /live-output
    environment:
      HUGO_DESTINATION: /live-output
-  - name: upload-live
-    image: eeacms/rsync
-    commands:
-    - eval `ssh-agent -s`
-    - echo "$CUSTOM_KEY" | ssh-add -
-    - mkdir -p ~/.ssh
-    - echo -e "Host *\n\tStrictHostKeyChecking no\n\n" > ~/.ssh/config
-    - rsync -rv -e "ssh -p 22" /live-output/ blog-live@danilafe.com:/var/www/blog-live/ --checksum
-    environment:
-      CUSTOM_KEY:
-        from_secret: live_ssh_key
-    volumes:
-    - name: live-output
-      path: /live-output
+# - name: upload-live
+#   image: eeacms/rsync
+#   commands:
+#   - eval `ssh-agent -s`
+#   - echo "$CUSTOM_KEY" | ssh-add -
+#   - mkdir -p ~/.ssh
+#   - echo -e "Host *\n\tStrictHostKeyChecking no\n\n" > ~/.ssh/config
+#   - rsync -rv -e "ssh -p 22" /live-output/ blog-live@danilafe.com:/var/www/blog-live/ --checksum
+#   environment:
+#     CUSTOM_KEY:
+#       from_secret: live_ssh_key
+#   volumes:
+#   - name: live-output
+#     path: /live-output
--- a/code/compiler/11/main.cpp
+++ b/code/compiler/11/main.cpp
@@ -139,7 +139,7 @@ void output_llvm(llvm_context& ctx, const std::string& filename) {
        if (ec) {
            throw 0;
        } else {
-            llvm::TargetMachine::CodeGenFileType type = llvm::TargetMachine::CGFT_ObjectFile;
+            llvm::CodeGenFileType type = llvm::CGFT_ObjectFile;
            llvm::legacy::PassManager pm;
            if (targetMachine->addPassesToEmitFile(pm, file, NULL, type)) {
                throw 0;
--- a/code/compiler/12/CMakeLists.txt
+++ b/code/compiler/12/CMakeLists.txt
@@ -0,0 +1,46 @@
+cmake_minimum_required(VERSION 3.1)
+project(compiler)
+
+# Find all the required packages
+find_package(BISON)
+find_package(FLEX)
+find_package(LLVM REQUIRED CONFIG)
+
+# Set up the flex and bison targets
+bison_target(parser
+    ${CMAKE_CURRENT_SOURCE_DIR}/parser.y
+    ${CMAKE_CURRENT_BINARY_DIR}/parser.cpp
+    COMPILE_FLAGS "-d")
+flex_target(scanner
+    ${CMAKE_CURRENT_SOURCE_DIR}/scanner.l
+    ${CMAKE_CURRENT_BINARY_DIR}/scanner.cpp)
+add_flex_bison_dependency(scanner parser)
+
+# Find all the relevant LLVM components
+llvm_map_components_to_libnames(LLVM_LIBS core x86asmparser x86codegen)
+
+# Create compiler executable
+add_executable(compiler
+    definition.cpp definition.hpp
+    parsed_type.cpp parsed_type.hpp
+    ast.cpp ast.hpp
+    llvm_context.cpp llvm_context.hpp
+    type_env.cpp type_env.hpp
+    env.cpp env.hpp
+    type.cpp type.hpp
+    error.cpp error.hpp
+    binop.cpp binop.hpp
+    instruction.cpp instruction.hpp
+    graph.cpp graph.hpp
+    global_scope.cpp global_scope.hpp
+    ${BISON_parser_OUTPUTS}
+    ${FLEX_scanner_OUTPUTS}
+    main.cpp
+)
+
+# Configure compiler executable
+target_include_directories(compiler PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
+target_include_directories(compiler PUBLIC ${CMAKE_CURRENT_BINARY_DIR})
+target_include_directories(compiler PUBLIC ${LLVM_INCLUDE_DIRS})
+target_compile_definitions(compiler PUBLIC ${LLVM_DEFINITIONS})
+target_link_libraries(compiler ${LLVM_LIBS})
--- a/code/compiler/12/ast.cpp
+++ b/code/compiler/12/ast.cpp
@@ -0,0 +1,437 @@
+#include "ast.hpp"
+#include <ostream>
+#include "binop.hpp"
+#include "error.hpp"
+#include "type_env.hpp"
+#include "env.hpp"
+
+static void print_indent(int n, std::ostream& to) {
+    while(n--) to << "  ";
+}
+
+void ast_int::print(int indent, std::ostream& to) const {
+    print_indent(indent, to);
+    to << "INT: " << value << std::endl;
+}
+
+void ast_int::find_free(std::set<std::string>& into) {
+
+}
+
+type_ptr ast_int::typecheck(type_mgr& mgr, type_env_ptr& env) {
+    this->env = env;
+    return type_ptr(new type_app(env->lookup_type("Int")));
+}
+
+void ast_int::translate(global_scope& scope) {
+
+}
+
+void ast_int::compile(const env_ptr& env, std::vector<instruction_ptr>& into) const {
+    into.push_back(instruction_ptr(new instruction_pushint(value)));
+}
+
+void ast_lid::print(int indent, std::ostream& to) const {
+    print_indent(indent, to);
+    to << "LID: " << id << std::endl;
+}
+
+void ast_lid::find_free(std::set<std::string>& into) {
+    into.insert(id);
+}
+
+type_ptr ast_lid::typecheck(type_mgr& mgr, type_env_ptr& env) {
+    this->env = env;
+    return env->lookup(id)->instantiate(mgr);
+}
+
+void ast_lid::translate(global_scope& scope) {
+
+}
+
+void ast_lid::compile(const env_ptr& env, std::vector<instruction_ptr>& into) const {
+    auto mangled_name = this->env->get_mangled_name(id);
+    into.push_back(instruction_ptr(
+        (env->has_variable(mangled_name) && !this->env->is_global(id)) ?
+            (instruction*) new instruction_push(env->get_offset(mangled_name)) :
+            (instruction*) new instruction_pushglobal(mangled_name)));
+}
+
+void ast_uid::print(int indent, std::ostream& to) const {
+    print_indent(indent, to);
+    to << "UID: " << id << std::endl;
+}
+
+void ast_uid::find_free(std::set<std::string>& into) {
+
+}
+
+type_ptr ast_uid::typecheck(type_mgr& mgr, type_env_ptr& env) {
+    this->env = env;
+    return env->lookup(id)->instantiate(mgr);
+}
+
+void ast_uid::translate(global_scope& scope) {
+
+}
+
+void ast_uid::compile(const env_ptr& env, std::vector<instruction_ptr>& into) const {
+    into.push_back(instruction_ptr(
+                new instruction_pushglobal(this->env->get_mangled_name(id))));
+}
+
+void ast_binop::print(int indent, std::ostream& to) const {
+    print_indent(indent, to);
+    to << "BINOP: " << op_name(op) << std::endl;
+    left->print(indent + 1, to);
+    right->print(indent + 1, to);
+}
+
+void ast_binop::find_free(std::set<std::string>& into) {
+    left->find_free(into);
+    right->find_free(into);
+}
+
+type_ptr ast_binop::typecheck(type_mgr& mgr, type_env_ptr& env) {
+    this->env = env;
+    type_ptr ltype = left->typecheck(mgr, env);
+    type_ptr rtype = right->typecheck(mgr, env);
+    type_ptr ftype = env->lookup(op_name(op))->instantiate(mgr);
+    if(!ftype) throw type_error(std::string("unknown binary operator ") + op_name(op));
+
+    type_ptr return_type = mgr.new_type();
+    type_ptr arrow_one = type_ptr(new type_arr(rtype, return_type));
+    type_ptr arrow_two = type_ptr(new type_arr(ltype, arrow_one));
+
+    mgr.unify(arrow_two, ftype);
+    return return_type;
+}
+
+void ast_binop::translate(global_scope& scope) {
+    left->translate(scope);
+    right->translate(scope);
+}
+
+void ast_binop::compile(const env_ptr& env, std::vector<instruction_ptr>& into) const {
+    right->compile(env, into);
+    left->compile(env_ptr(new env_offset(1, env)), into);
+
+    into.push_back(instruction_ptr(new instruction_pushglobal(op_action(op))));
+    into.push_back(instruction_ptr(new instruction_mkapp()));
+    into.push_back(instruction_ptr(new instruction_mkapp()));
+}
+
+void ast_app::print(int indent, std::ostream& to) const {
+    print_indent(indent, to);
+    to << "APP:" << std::endl;
+    left->print(indent + 1, to);
+    right->print(indent + 1, to);
+}
+
+void ast_app::find_free(std::set<std::string>& into) {
+    left->find_free(into);
+    right->find_free(into);
+}
+
+type_ptr ast_app::typecheck(type_mgr& mgr, type_env_ptr& env) {
+    this->env = env;
+    type_ptr ltype = left->typecheck(mgr, env);
+    type_ptr rtype = right->typecheck(mgr, env);
+
+    type_ptr return_type = mgr.new_type();
+    type_ptr arrow = type_ptr(new type_arr(rtype, return_type));
+    mgr.unify(arrow, ltype);
+    return return_type;
+}
+
+void ast_app::translate(global_scope& scope) {
+    left->translate(scope);
+    right->translate(scope);
+}
+
+void ast_app::compile(const env_ptr& env, std::vector<instruction_ptr>& into) const {
+    right->compile(env, into);
+    left->compile(env_ptr(new env_offset(1, env)), into);
+    into.push_back(instruction_ptr(new instruction_mkapp()));
+}
+
+void ast_case::print(int indent, std::ostream& to) const {
+    print_indent(indent, to);
+    to << "CASE: " << std::endl;
+    for(auto& branch : branches) {
+        print_indent(indent + 1, to);
+        branch->pat->print(to);
+        to << std::endl;
+        branch->expr->print(indent + 2, to);
+    }
+}
+
+void ast_case::find_free(std::set<std::string>& into) {
+    of->find_free(into);
+    for(auto& branch : branches) {
+        std::set<std::string> free_in_branch;
+        std::set<std::string> pattern_variables;
+        branch->pat->find_variables(pattern_variables);
+        branch->expr->find_free(free_in_branch);
+        for(auto& free : free_in_branch) {
+            if(pattern_variables.find(free) == pattern_variables.end())
+                into.insert(free);
+        }
+    }
+}
+
+type_ptr ast_case::typecheck(type_mgr& mgr, type_env_ptr& env) {
+    this->env = env;
+    type_var* var;
+    type_ptr case_type = mgr.resolve(of->typecheck(mgr, env), var);
+    type_ptr branch_type = mgr.new_type();
+
+    for(auto& branch : branches) {
+        type_env_ptr new_env = type_scope(env);
+        branch->pat->typecheck(case_type, mgr, new_env);
+        type_ptr curr_branch_type = branch->expr->typecheck(mgr, new_env);
+        mgr.unify(branch_type, curr_branch_type);
+    }
+
+    input_type = mgr.resolve(case_type, var);
+    type_app* app_type;
+    if(!(app_type = dynamic_cast<type_app*>(input_type.get())) ||
+            !dynamic_cast<type_data*>(app_type->constructor.get())) {
+        throw type_error("attempting case analysis of non-data type");
+    }
+
+    return branch_type;
+}
+
+void ast_case::translate(global_scope& scope) {
+    of->translate(scope);
+    for(auto& branch : branches) {
+        branch->expr->translate(scope);
+    }
+}
+
+void ast_case::compile(const env_ptr& env, std::vector<instruction_ptr>& into) const {
+    type_app* app_type = dynamic_cast<type_app*>(input_type.get());
+    type_data* type = dynamic_cast<type_data*>(app_type->constructor.get());
+
+    of->compile(env, into);
+    into.push_back(instruction_ptr(new instruction_eval()));
+
+    instruction_jump* jump_instruction = new instruction_jump();
+    into.push_back(instruction_ptr(jump_instruction));
+    for(auto& branch : branches) {
+        std::vector<instruction_ptr> branch_instructions;
+        pattern_var* vpat;
+        pattern_constr* cpat;
+
+        if((vpat = dynamic_cast<pattern_var*>(branch->pat.get()))) {
+            branch->expr->compile(env_ptr(new env_offset(1, env)), branch_instructions);
+
+            for(auto& constr_pair : type->constructors) {
+                if(jump_instruction->tag_mappings.find(constr_pair.second.tag) !=
+                        jump_instruction->tag_mappings.end())
+                    break;
+
+                jump_instruction->tag_mappings[constr_pair.second.tag] =
+                    jump_instruction->branches.size();
+            }
+            jump_instruction->branches.push_back(std::move(branch_instructions));
+        } else if((cpat = dynamic_cast<pattern_constr*>(branch->pat.get()))) {
+            env_ptr new_env = env;
+            for(auto it = cpat->params.rbegin(); it != cpat->params.rend(); it++) {
+                new_env = env_ptr(new env_var(branch->expr->env->get_mangled_name(*it), new_env));
+            }
+
+            branch_instructions.push_back(instruction_ptr(new instruction_split(
+                            cpat->params.size())));
+            branch->expr->compile(new_env, branch_instructions);
+            branch_instructions.push_back(instruction_ptr(new instruction_slide(
+                            cpat->params.size())));
+
+            int new_tag = type->constructors[cpat->constr].tag;
+            if(jump_instruction->tag_mappings.find(new_tag) !=
+                    jump_instruction->tag_mappings.end())
+                throw type_error("technically not a type error: duplicate pattern");
+
+            jump_instruction->tag_mappings[new_tag] =
+                jump_instruction->branches.size();
+            jump_instruction->branches.push_back(std::move(branch_instructions));
+        }
+    }
+
+    for(auto& constr_pair : type->constructors) {
+        if(jump_instruction->tag_mappings.find(constr_pair.second.tag) ==
+                jump_instruction->tag_mappings.end())
+            throw type_error("non-total pattern");
+    }
+}
+
+void ast_let::print(int indent, std::ostream& to) const {
+    print_indent(indent, to);
+    to << "LET: " << std::endl;
+    in->print(indent + 1, to);
+}
+
+void ast_let::find_free(std::set<std::string>& into) {
+    definitions.find_free(into);
+    std::set<std::string> all_free;
+    in->find_free(all_free);
+    for(auto& free_var : all_free) {
+        if(definitions.defs_defn.find(free_var) == definitions.defs_defn.end())
+            into.insert(free_var);
+    }
+}
+
+type_ptr ast_let::typecheck(type_mgr& mgr, type_env_ptr& env) {
+    this->env = env;
+    definitions.typecheck(mgr, env);
+    return in->typecheck(mgr, definitions.env);
+}
+
+void ast_let::translate(global_scope& scope) {
+    for(auto& def : definitions.defs_data) {
+        def.second->into_globals(scope);
+    }
+    for(auto& def : definitions.defs_defn) {
+        size_t original_params = def.second->params.size();
+        std::string original_name = def.second->name;
+        auto& global_definition = def.second->into_global(scope);
+        size_t captured = global_definition.params.size() - original_params;
+
+        type_env_ptr mangled_env = type_scope(env);
+        mangled_env->bind(def.first, env->lookup(def.first), visibility::global);
+        mangled_env->set_mangled_name(def.first, global_definition.name);
+
+        ast_ptr global_app(new ast_lid(original_name));
+        global_app->env = mangled_env;
+        for(auto& param : global_definition.params) {
+            if(!(captured--)) break;
+            ast_ptr new_arg(new ast_lid(param));
+            new_arg->env = env;
+            global_app = ast_ptr(new ast_app(std::move(global_app), std::move(new_arg)));
+            global_app->env = env;
+        }
+        translated_definitions.push_back({ def.first, std::move(global_app) });
+    }
+    in->translate(scope);
+}
+
+void ast_let::compile(const env_ptr& env, std::vector<instruction_ptr>& into) const {
+    into.push_back(instruction_ptr(new instruction_alloc(translated_definitions.size())));
+    env_ptr new_env = env;
+    for(auto& def : translated_definitions) {
+        new_env = env_ptr(new env_var(definitions.env->get_mangled_name(def.first), std::move(new_env)));
+    }
+    int offset = translated_definitions.size() - 1;
+    for(auto& def : translated_definitions) {
+        def.second->compile(new_env, into);
+        into.push_back(instruction_ptr(new instruction_update(offset--)));
+    }
+    in->compile(new_env, into);
+    into.push_back(instruction_ptr(new instruction_slide(translated_definitions.size())));
+}
+
+void ast_lambda::print(int indent, std::ostream&  to) const {
+    print_indent(indent, to);
+    to << "LAMBDA";
+    for(auto& param : params) {
+        to << " " << param;
+    }
+    to << std::endl;
+    body->print(indent+1, to);
+}
+
+void ast_lambda::find_free(std::set<std::string>& into) {
+    body->find_free(free_variables);
+    for(auto& param : params) {
+        free_variables.erase(param);
+    }
+    into.insert(free_variables.begin(), free_variables.end());
+}
+
+type_ptr ast_lambda::typecheck(type_mgr& mgr, type_env_ptr& env) {
+    this->env = env;
+    var_env = type_scope(env);
+    type_ptr return_type = mgr.new_type();
+    type_ptr full_type = return_type;
+
+    for(auto it = params.rbegin(); it != params.rend(); it++) {
+        type_ptr param_type = mgr.new_type();
+        var_env->bind(*it, param_type);
+        full_type = type_ptr(new type_arr(std::move(param_type), full_type));
+    }
+
+    mgr.unify(return_type, body->typecheck(mgr, var_env));
+    return full_type;
+}
+
+void ast_lambda::translate(global_scope& scope) {
+    std::vector<std::string> function_params;
+    for(auto& free_variable : free_variables) {
+        if(env->is_global(free_variable)) continue;
+        function_params.push_back(free_variable);
+    }
+    size_t captured_count = function_params.size();
+    function_params.insert(function_params.end(), params.begin(), params.end());
+
+    auto& new_function = scope.add_function("lambda", std::move(function_params), std::move(body));
+    type_env_ptr mangled_env = type_scope(env);
+    mangled_env->bind("lambda", type_scheme_ptr(nullptr), visibility::global);
+    mangled_env->set_mangled_name("lambda", new_function.name);
+    ast_ptr new_application = ast_ptr(new ast_lid("lambda"));
+    new_application->env = mangled_env;
+
+    for(auto& param : new_function.params) {
+        if(!(captured_count--)) break;
+        ast_ptr new_arg = ast_ptr(new ast_lid(param));
+        new_arg->env = env;
+        new_application = ast_ptr(new ast_app(std::move(new_application), std::move(new_arg)));
+        new_application->env = env;
+    }
+    translated = std::move(new_application);
+}
+
+void ast_lambda::compile(const env_ptr& env, std::vector<instruction_ptr>& into) const {
+    translated->compile(env, into);
+}
+
+void pattern_var::print(std::ostream& to) const {
+    to << var;
+}
+
+void pattern_var::find_variables(std::set<std::string>& into) const {
+    into.insert(var);
+}
+
+void pattern_var::typecheck(type_ptr t, type_mgr& mgr, type_env_ptr& env) const {
+    env->bind(var, t);
+}
+
+void pattern_constr::print(std::ostream& to) const {
+    to << constr;
+    for(auto& param : params) {
+        to << " " << param;
+    }
+}
+
+void pattern_constr::find_variables(std::set<std::string>& into) const {
+    into.insert(params.begin(), params.end());
+}
+
+void pattern_constr::typecheck(type_ptr t, type_mgr& mgr, type_env_ptr& env) const {
+    type_scheme_ptr constructor_type_scheme = env->lookup(constr);
+    if(!constructor_type_scheme) {
+        throw type_error(std::string("pattern using unknown constructor ") + constr);
+    }
+    type_ptr constructor_type = constructor_type_scheme->instantiate(mgr);
+
+    for(auto& param : params) {
+        type_arr* arr = dynamic_cast<type_arr*>(constructor_type.get());
+        if(!arr) throw type_error("too many parameters in constructor pattern");
+
+        env->bind(param, arr->left);
+        constructor_type = arr->right;
+    }
+
+    mgr.unify(t, constructor_type);
+}
--- a/code/compiler/12/ast.hpp
+++ b/code/compiler/12/ast.hpp
@@ -0,0 +1,189 @@
+#pragma once
+#include <memory>
+#include <vector>
+#include <set>
+#include "type.hpp"
+#include "type_env.hpp"
+#include "binop.hpp"
+#include "instruction.hpp"
+#include "env.hpp"
+#include "definition.hpp"
+#include "global_scope.hpp"
+
+struct ast {
+    type_env_ptr env;
+
+    virtual ~ast() = default;
+
+    virtual void print(int indent, std::ostream& to) const = 0;
+    virtual void find_free(std::set<std::string>& into) = 0;
+    virtual type_ptr typecheck(type_mgr& mgr, type_env_ptr& env) = 0;
+    virtual void translate(global_scope& scope) = 0;
+    virtual void compile(const env_ptr& env,
+        std::vector<instruction_ptr>& into) const = 0;
+};
+
+using ast_ptr = std::unique_ptr<ast>;
+
+struct pattern {
+    virtual ~pattern() = default;
+
+    virtual void print(std::ostream& to) const = 0;
+    virtual void find_variables(std::set<std::string>& into) const = 0;
+    virtual void typecheck(type_ptr t, type_mgr& mgr, type_env_ptr& env) const = 0;
+};
+
+using pattern_ptr = std::unique_ptr<pattern>;
+
+struct branch {
+    pattern_ptr pat;
+    ast_ptr expr;
+
+    branch(pattern_ptr p, ast_ptr a)
+        : pat(std::move(p)), expr(std::move(a)) {}
+};
+
+using branch_ptr = std::unique_ptr<branch>;
+
+struct ast_int : public ast {
+    int value;
+
+    explicit ast_int(int v)
+        : value(v) {}
+
+    void print(int indent, std::ostream& to) const;
+    void find_free(std::set<std::string>& into);
+    type_ptr typecheck(type_mgr& mgr, type_env_ptr& env);
+    void translate(global_scope& scope);
+    void compile(const env_ptr& env, std::vector<instruction_ptr>& into) const;
+};
+
+struct ast_lid : public ast {
+    std::string id;
+
+    explicit ast_lid(std::string i)
+        : id(std::move(i)) {}
+
+    void print(int indent, std::ostream& to) const;
+    void find_free(std::set<std::string>& into);
+    type_ptr typecheck(type_mgr& mgr, type_env_ptr& env);
+    void translate(global_scope& scope);
+    void compile(const env_ptr& env, std::vector<instruction_ptr>& into) const;
+};
+
+struct ast_uid : public ast {
+    std::string id;
+
+    explicit ast_uid(std::string i)
+        : id(std::move(i)) {}
+
+    void print(int indent, std::ostream& to) const;
+    void find_free(std::set<std::string>& into);
+    type_ptr typecheck(type_mgr& mgr, type_env_ptr& env);
+    void translate(global_scope& scope);
+    void compile(const env_ptr& env, std::vector<instruction_ptr>& into) const;
+};
+
+struct ast_binop : public ast {
+    binop op;  
+    ast_ptr left;
+    ast_ptr right;
+
+    ast_binop(binop o, ast_ptr l, ast_ptr r)
+        : op(o), left(std::move(l)), right(std::move(r)) {}
+
+    void print(int indent, std::ostream& to) const;
+    void find_free(std::set<std::string>& into);
+    type_ptr typecheck(type_mgr& mgr, type_env_ptr& env);
+    void translate(global_scope& scope);
+    void compile(const env_ptr& env, std::vector<instruction_ptr>& into) const;
+};
+
+struct ast_app : public ast {
+    ast_ptr left;
+    ast_ptr right;
+
+    ast_app(ast_ptr l, ast_ptr r)
+        : left(std::move(l)), right(std::move(r)) {}
+
+    void print(int indent, std::ostream& to) const;
+    void find_free(std::set<std::string>& into);
+    type_ptr typecheck(type_mgr& mgr, type_env_ptr& env);
+    void translate(global_scope& scope);
+    void compile(const env_ptr& env, std::vector<instruction_ptr>& into) const;
+};
+
+struct ast_case : public ast {
+    ast_ptr of;
+    type_ptr input_type;
+    std::vector<branch_ptr> branches;
+
+    ast_case(ast_ptr o, std::vector<branch_ptr> b)
+        : of(std::move(o)), branches(std::move(b)) {}
+
+    void print(int indent, std::ostream& to) const;
+    void find_free(std::set<std::string>& into);
+    type_ptr typecheck(type_mgr& mgr, type_env_ptr& env);
+    void translate(global_scope& scope);
+    void compile(const env_ptr& env, std::vector<instruction_ptr>& into) const;
+};
+
+struct ast_let : public ast {
+    using basic_definition = std::pair<std::string, ast_ptr>;
+
+    definition_group definitions;
+    ast_ptr in;
+
+    std::vector<basic_definition> translated_definitions;
+
+    ast_let(definition_group g, ast_ptr i)
+        : definitions(std::move(g)), in(std::move(i)) {}
+
+    void print(int indent, std::ostream& to) const;
+    void find_free(std::set<std::string>& into);
+    type_ptr typecheck(type_mgr& mgr, type_env_ptr& env);
+    void translate(global_scope& scope);
+    void compile(const env_ptr& env, std::vector<instruction_ptr>& into) const;
+};
+
+struct ast_lambda : public ast {
+    std::vector<std::string> params;
+    ast_ptr body;
+
+    type_env_ptr var_env;
+
+    std::set<std::string> free_variables;
+    ast_ptr translated;
+
+    ast_lambda(std::vector<std::string> ps, ast_ptr b)
+        : params(std::move(ps)), body(std::move(b)) {}
+
+    void print(int indent, std::ostream& to) const;
+    void find_free(std::set<std::string>& into);
+    type_ptr typecheck(type_mgr& mgr, type_env_ptr& env);
+    void translate(global_scope& scope);
+    void compile(const env_ptr& env, std::vector<instruction_ptr>& into) const;
+};
+
+struct pattern_var : public pattern {
+    std::string var;
+
+    pattern_var(std::string v)
+        : var(std::move(v)) {}
+
+    void print(std::ostream &to) const;
+    void find_variables(std::set<std::string>& into) const;
+    void typecheck(type_ptr t, type_mgr& mgr, type_env_ptr& env) const;
+};
+
+struct pattern_constr : public pattern {
+    std::string constr;
+    std::vector<std::string> params;
+
+    pattern_constr(std::string c, std::vector<std::string> p)
+        : constr(std::move(c)), params(std::move(p)) {}
+
+    void print(std::ostream &to) const;
+    void find_variables(std::set<std::string>& into) const;
+    virtual void typecheck(type_ptr t, type_mgr& mgr, type_env_ptr& env) const;
+};
--- a/code/compiler/12/binop.cpp
+++ b/code/compiler/12/binop.cpp
@@ -0,0 +1,21 @@
+#include "binop.hpp"
+
+std::string op_name(binop op) {
+    switch(op) {
+        case PLUS: return "+";
+        case MINUS: return "-";
+        case TIMES: return "*";
+        case DIVIDE: return "/";
+    }
+    return "??";
+}
+
+std::string op_action(binop op) {
+    switch(op) {
+        case PLUS: return "plus";
+        case MINUS: return "minus";
+        case TIMES: return "times";
+        case DIVIDE: return "divide";
+    }
+    return "??";
+}
--- a/code/compiler/12/binop.hpp
+++ b/code/compiler/12/binop.hpp
@@ -0,0 +1,12 @@
+#pragma once
+#include <string>
+
+enum binop {
+    PLUS,
+    MINUS,
+    TIMES,
+    DIVIDE
+};
+
+std::string op_name(binop op);
+std::string op_action(binop op);
--- a/code/compiler/12/definition.cpp
+++ b/code/compiler/12/definition.cpp
@@ -0,0 +1,145 @@
+#include "definition.hpp"
+#include "error.hpp"
+#include "ast.hpp"
+#include "instruction.hpp"
+#include "llvm_context.hpp"
+#include "type.hpp"
+#include "type_env.hpp"
+#include "graph.hpp"
+#include <llvm/IR/DerivedTypes.h>
+#include <llvm/IR/Function.h>
+#include <llvm/IR/Type.h>
+
+void definition_defn::find_free() {
+    body->find_free(free_variables);
+    for(auto& param : params) {
+        free_variables.erase(param);
+    }
+}
+
+void definition_defn::insert_types(type_mgr& mgr, type_env_ptr& env, visibility v) {
+    this->env = env;
+    var_env = type_scope(env);
+    return_type = mgr.new_type();
+    full_type = return_type;
+
+    for(auto it = params.rbegin(); it != params.rend(); it++) {
+        type_ptr param_type = mgr.new_type();
+        full_type = type_ptr(new type_arr(param_type, full_type));
+        var_env->bind(*it, param_type);
+    }
+    env->bind(name, full_type, v);
+}
+
+void definition_defn::typecheck(type_mgr& mgr) {
+    type_ptr body_type = body->typecheck(mgr, var_env);
+    mgr.unify(return_type, body_type);
+}
+
+
+global_function& definition_defn::into_global(global_scope& scope) {
+    std::vector<std::string> all_params;
+    for(auto& free : free_variables) {
+        if(env->is_global(free)) continue;
+        all_params.push_back(free);
+    }
+    all_params.insert(all_params.end(), params.begin(), params.end());
+    body->translate(scope);
+    return scope.add_function(name, std::move(all_params), std::move(body));
+}
+
+void definition_data::insert_types(type_env_ptr& env) {
+    this->env = env;
+    env->bind_type(name, type_ptr(new type_data(name, vars.size())));
+}
+
+void definition_data::insert_constructors() const {
+    type_ptr this_type_ptr = env->lookup_type(name);
+    type_data* this_type = static_cast<type_data*>(this_type_ptr.get());
+    int next_tag = 0;
+
+    std::set<std::string> var_set;
+    type_app* return_app = new type_app(std::move(this_type_ptr));
+    type_ptr return_type(return_app);
+    for(auto& var : vars) {
+        if(var_set.find(var) != var_set.end()) throw 0;
+        var_set.insert(var);
+        return_app->arguments.push_back(type_ptr(new type_var(var)));
+    }
+
+    for(auto& constructor : constructors) {
+        constructor->tag = next_tag;
+        this_type->constructors[constructor->name] = { next_tag++ };
+
+        type_ptr full_type = return_type;
+        for(auto it = constructor->types.rbegin(); it != constructor->types.rend(); it++) {
+            type_ptr type = (*it)->to_type(var_set, env);
+            full_type = type_ptr(new type_arr(type, full_type));
+        }
+
+        type_scheme_ptr full_scheme(new type_scheme(std::move(full_type)));
+        full_scheme->forall.insert(full_scheme->forall.begin(), vars.begin(), vars.end());
+        env->bind(constructor->name, full_scheme);
+    }
+}
+
+void definition_data::into_globals(global_scope& scope) {
+    for(auto& constructor : constructors) {
+        global_constructor& c = scope.add_constructor(
+                constructor->name, constructor->tag, constructor->types.size());
+        env->set_mangled_name(constructor->name, c.name);
+    }
+}
+
+void definition_group::find_free(std::set<std::string>& into) {
+    for(auto& def_pair : defs_defn) {
+        def_pair.second->find_free();
+        for(auto& free_var : def_pair.second->free_variables) {
+            if(defs_defn.find(free_var) == defs_defn.end()) {
+                into.insert(free_var);
+            } else {
+                def_pair.second->nearby_variables.insert(free_var);
+            }
+        }
+    }
+}
+
+void definition_group::typecheck(type_mgr& mgr, type_env_ptr& env) {
+    this->env = type_scope(env);
+
+    for(auto& def_data : defs_data) {
+        def_data.second->insert_types(this->env);
+    }
+    for(auto& def_data : defs_data) {
+        def_data.second->insert_constructors();
+    }
+
+    function_graph dependency_graph;
+
+    for(auto& def_defn : defs_defn) {
+        def_defn.second->find_free();
+        dependency_graph.add_function(def_defn.second->name);
+
+        for(auto& dependency : def_defn.second->nearby_variables) {
+            if(defs_defn.find(dependency) == defs_defn.end())
+                throw 0;
+            dependency_graph.add_edge(def_defn.second->name, dependency);
+        }
+    }
+
+    std::vector<group_ptr> groups = dependency_graph.compute_order();
+    for(auto it = groups.rbegin(); it != groups.rend(); it++) {
+        auto& group = *it;
+        for(auto& def_defnn_name : group->members) {
+            auto& def_defn = defs_defn.find(def_defnn_name)->second;
+            def_defn->insert_types(mgr, this->env, vis);
+        }
+        for(auto& def_defnn_name : group->members) {
+            auto& def_defn = defs_defn.find(def_defnn_name)->second;
+            def_defn->typecheck(mgr);
+        }
+        for(auto& def_defnn_name : group->members) {
+            this->env->generalize(def_defnn_name, *group, mgr);
+        }
+    }
+}
--- a/code/compiler/12/definition.hpp
+++ b/code/compiler/12/definition.hpp
@@ -0,0 +1,83 @@
+#pragma once
+#include <memory>
+#include <vector>
+#include <map>
+#include <set>
+#include "instruction.hpp"
+#include "llvm_context.hpp"
+#include "parsed_type.hpp"
+#include "type_env.hpp"
+#include "global_scope.hpp"
+
+struct ast;
+using ast_ptr = std::unique_ptr<ast>;
+
+struct constructor {
+    std::string name;
+    std::vector<parsed_type_ptr> types;
+    int8_t tag;
+
+    constructor(std::string n, std::vector<parsed_type_ptr> ts)
+        : name(std::move(n)), types(std::move(ts)) {}
+};
+
+using constructor_ptr = std::unique_ptr<constructor>;
+
+struct definition_defn {
+    std::string name;
+    std::vector<std::string> params;
+    ast_ptr body;
+
+    type_env_ptr env;
+    type_env_ptr var_env;
+    std::set<std::string> free_variables;
+    std::set<std::string> nearby_variables;
+    type_ptr full_type;
+    type_ptr return_type;
+
+    definition_defn(std::string n, std::vector<std::string> p, ast_ptr b)
+        : name(std::move(n)), params(std::move(p)), body(std::move(b)) {
+
+    }
+
+    void find_free();
+    void insert_types(type_mgr& mgr, type_env_ptr& env, visibility v);
+    void typecheck(type_mgr& mgr);
+
+    global_function& into_global(global_scope& scope);
+};
+
+using definition_defn_ptr = std::unique_ptr<definition_defn>;
+
+struct definition_data {
+    std::string name;
+    std::vector<std::string> vars;
+    std::vector<constructor_ptr> constructors;
+
+    type_env_ptr env;
+
+    definition_data(
+            std::string n,
+            std::vector<std::string> vs,
+            std::vector<constructor_ptr> cs)
+        : name(std::move(n)), vars(std::move(vs)), constructors(std::move(cs)) {}
+
+    void insert_types(type_env_ptr& env);
+    void insert_constructors() const;
+
+    void into_globals(global_scope& scope);
+};
+
+using definition_data_ptr = std::unique_ptr<definition_data>;
+
+struct definition_group {
+    std::map<std::string, definition_data_ptr> defs_data;
+    std::map<std::string, definition_defn_ptr> defs_defn;
+    visibility vis;
+    type_env_ptr env;
+
+    definition_group(visibility v = visibility::local) : vis(v) {}
+
+    void find_free(std::set<std::string>& into);
+    void typecheck(type_mgr& mgr, type_env_ptr& env);
+};
--- a/code/compiler/12/env.cpp
+++ b/code/compiler/12/env.cpp
@@ -0,0 +1,23 @@
+#include "env.hpp"
+
+int env_var::get_offset(const std::string& name) const {
+    if(name == this->name) return 0;
+    if(parent) return parent->get_offset(name) + 1;
+    throw 0;
+}
+
+bool env_var::has_variable(const std::string& name) const {
+    if(name == this->name) return true;
+    if(parent) return parent->has_variable(name);
+    return false;
+}
+
+int env_offset::get_offset(const std::string& name) const {
+    if(parent) return parent->get_offset(name) + offset;
+    throw 0;
+}
+
+bool env_offset::has_variable(const std::string& name) const {
+    if(parent) return parent->has_variable(name);
+    return false;
+}
--- a/code/compiler/12/env.hpp
+++ b/code/compiler/12/env.hpp
@@ -0,0 +1,34 @@
+#pragma once
+#include <memory>
+#include <string>
+
+struct env {
+    virtual ~env() = default;
+
+    virtual int get_offset(const std::string& name) const = 0;
+    virtual bool has_variable(const std::string& name) const = 0;
+};
+
+using env_ptr = std::shared_ptr<env>;
+
+struct env_var : public env {
+    std::string name;
+    env_ptr parent;
+
+    env_var(std::string n, env_ptr p)
+        : name(std::move(n)), parent(std::move(p)) {}
+
+    int get_offset(const std::string& name) const;
+    bool has_variable(const std::string& name) const;
+};
+
+struct env_offset : public env {
+    int offset;
+    env_ptr parent;
+
+    env_offset(int o, env_ptr p)
+        : offset(o), parent(std::move(p)) {}
+
+    int get_offset(const std::string& name) const;
+    bool has_variable(const std::string& name) const;
+};
--- a/code/compiler/12/error.cpp
+++ b/code/compiler/12/error.cpp
@@ -0,0 +1,5 @@
+#include "error.hpp"
+
+const char* type_error::what() const noexcept {
+    return "an error occured while checking the types of the program";
+}
--- a/code/compiler/12/error.hpp
+++ b/code/compiler/12/error.hpp
@@ -0,0 +1,21 @@
+#pragma once
+#include <exception>
+#include "type.hpp"
+
+struct type_error : std::exception {
+    std::string description;
+
+    type_error(std::string d)
+        : description(std::move(d)) {}
+
+    const char* what() const noexcept override;
+};
+
+struct unification_error : public type_error {
+    type_ptr left;
+    type_ptr right;
+
+    unification_error(type_ptr l, type_ptr r)
+        : left(std::move(l)), right(std::move(r)), 
+            type_error("failed to unify types") {}
+};
--- a/code/compiler/12/examples/bad1.txt
+++ b/code/compiler/12/examples/bad1.txt
@@ -0,0 +1,2 @@
+data Bool = { True, False }
+defn main = { 3 + True }
--- a/code/compiler/12/examples/bad2.txt
+++ b/code/compiler/12/examples/bad2.txt
@@ -0,0 +1 @@
+defn main = { 1 2 3 4 5 }
--- a/code/compiler/12/examples/bad3.txt
+++ b/code/compiler/12/examples/bad3.txt
@@ -0,0 +1,8 @@
+data List = { Nil, Cons Int List }
+
+defn head l = {
+    case l of {
+        Nil -> { 0 }
+        Cons x y z -> { x }
+    }
+}
--- a/code/compiler/12/examples/fixpoint.txt
+++ b/code/compiler/12/examples/fixpoint.txt
@@ -0,0 +1,17 @@
+data List a = { Nil, Cons a (List a) }
+
+defn fix f = { let { defn x = { f x } } in { x } }
+defn fixpointOnes fo = { Cons 1 fo }
+defn sumTwo l = {
+    case l of {
+        Nil -> { 0 }
+        Cons x xs -> {
+            x + case xs of {
+                Nil -> { 0 }
+                Cons y ys -> { y }
+            }
+        }
+    }
+}
+
+defn main = { sumTwo (fix fixpointOnes) }
--- a/code/compiler/12/examples/if.txt
+++ b/code/compiler/12/examples/if.txt
@@ -0,0 +1,8 @@
+data Bool = { True, False }
+defn if c t e = {
+    case c of {
+        True -> { t }
+        False -> { e }
+    }
+}
+defn main = { if (if True False True) 11 3 }
--- a/code/compiler/12/examples/lambda.txt
+++ b/code/compiler/12/examples/lambda.txt
@@ -0,0 +1,19 @@
+data List a = { Nil, Cons a (List a) }
+
+defn sum l = {
+    case l of {
+        Nil -> { 0 }
+        Cons x xs -> { x + sum xs}
+    }
+}
+
+defn map f l = {
+    case l of {
+        Nil -> { Nil }
+        Cons x xs -> { Cons (f x) (map f xs) }
+    }
+}
+
+defn main = {
+    sum (map \x -> { x * x } (map (\x -> { x + x }) (Cons 1 (Cons 2 (Cons 3 Nil)))))
+}
--- a/code/compiler/12/examples/letin.txt
+++ b/code/compiler/12/examples/letin.txt
@@ -0,0 +1,47 @@
+data Bool = { True, False }
+
+data List a = { Nil, Cons a (List a) }
+
+defn if c t e = {
+    case c of {
+        True -> { t }
+        False -> { e }
+    }
+}
+
+defn mergeUntil l r p = {
+    let {
+        defn mergeLeft nl nr = {
+            case nl of {
+                Nil -> { Nil }
+                Cons x xs -> { if (p x) (Cons x (mergeRight xs nr)) Nil }
+            }
+        }
+        defn mergeRight nl nr = {
+            case nr of {
+                Nil -> { Nil }
+                Cons x xs -> { if (p x) (Cons x (mergeLeft nl xs)) Nil }
+            }
+        }
+    } in {
+        mergeLeft l r
+    }
+}
+
+defn const x y = { x }
+
+defn sum l = {
+    case l of {
+        Nil -> { 0 }
+        Cons x xs -> { x + sum xs }
+    }
+}
+
+defn main = {
+    let {
+        defn firstList = { Cons 1 (Cons 3 (Cons 5 Nil)) }
+        defn secondList = { Cons 2 (Cons 4 (Cons 6 Nil)) }
+    } in {
+        sum (mergeUntil firstList secondList (const True))
+    }
+}
--- a/code/compiler/12/examples/list.txt
+++ b/code/compiler/12/examples/list.txt
@@ -0,0 +1,32 @@
+data List a = { Nil, Cons a (List a) }
+
+defn map f l = {
+    case l of {
+        Nil -> { Nil }
+        Cons x xs -> { Cons (f x) (map f xs) }
+    }
+}
+
+defn foldl f b l = {
+    case l of {
+        Nil -> { b }
+        Cons x xs -> { foldl f (f b x) xs }
+    }
+}
+
+defn foldr f b l = {
+    case l of {
+        Nil -> { b }
+        Cons x xs -> { f x (foldr f b xs) }
+    }
+}
+
+defn list = { Cons 1 (Cons 2 (Cons 3 (Cons 4 Nil))) }
+
+defn add x y = { x + y }
+defn sum l = { foldr add 0 l }
+
+defn skipAdd x y = { y + 1 }
+defn length l = { foldr skipAdd 0 l }
+
+defn main = { sum list + length list }
--- a/code/compiler/12/examples/mutual_recursion.txt
+++ b/code/compiler/12/examples/mutual_recursion.txt
@@ -0,0 +1,25 @@
+data Bool = { True, False }
+data List = { Nil, Cons Int List }
+
+defn if c t e = {
+    case c of {
+        True -> { t }
+        False -> { e }
+    }
+}
+
+defn oddEven l e = {
+    case l of {
+        Nil -> { e }
+        Cons x xs -> { evenOdd xs e }
+    }
+}
+
+defn evenOdd l e = {
+    case l of {
+        Nil -> { e }
+        Cons x xs -> { oddEven xs e }
+    }
+}
+
+defn main = { if (oddEven (Cons 1 (Cons 2 (Cons 3 Nil))) True) (oddEven (Cons 1 (Cons 2 (Cons 3 Nil))) 1) 3 }
--- a/code/compiler/12/examples/packed.txt
+++ b/code/compiler/12/examples/packed.txt
@@ -0,0 +1,23 @@
+data Pair a b = { Pair a b }
+
+defn packer = {
+    let {
+        data Packed a = { Packed a }
+        defn pack a = { Packed a }
+        defn unpack p = {
+            case p of {
+                Packed a -> { a }
+            }
+        }
+    } in {
+        Pair pack unpack
+    }
+}
+
+defn main = { 
+    case packer of {
+        Pair pack unpack -> {
+            unpack (pack 3)
+        }
+    }
+}
--- a/code/compiler/12/examples/pair.txt
+++ b/code/compiler/12/examples/pair.txt
@@ -0,0 +1,17 @@
+data Pair a b = { MkPair a b }
+
+defn fst p = {
+    case p of {
+        MkPair a b -> { a }
+    }
+}
+
+defn snd p = {
+    case p of {
+        MkPair a b -> { b }
+    }
+}
+
+defn pair = { MkPair 1 (MkPair 2 3) }
+
+defn main = { fst pair + snd (snd pair) }
--- a/code/compiler/12/examples/primes.txt
+++ b/code/compiler/12/examples/primes.txt
@@ -0,0 +1,122 @@
+data List = { Nil, Cons Nat List }
+data Bool = { True, False }
+data Nat = { O, S Nat }
+
+defn if c t e = {
+    case c of {
+        True -> { t }
+        False -> { e }
+    }
+}
+
+defn toInt n = {
+    case n of {
+        O -> { 0 }
+        S np -> { 1 + toInt np }
+    }
+}
+
+defn lte n m = {
+    case m of {
+        O -> {
+            case n of {
+                O -> { True }
+                S np -> { False }
+            }
+        }
+        S mp -> {
+            case n of {
+                O -> { True }
+                S np -> { lte np mp }
+            }
+        }
+    }
+}
+
+defn minus n m = {
+    case m of {
+        O -> { n }
+        S mp -> { 
+            case n of {
+                O -> { O }
+                S np -> {
+                    minus np mp
+                }
+            }
+        }
+    }
+}
+
+defn mod n m = {
+    if (lte m n) (mod (minus n m) m) n
+}
+
+defn notDivisibleBy n m = {
+    case (mod m n) of {
+        O -> { False }
+        S mp -> { True }
+    }
+}
+
+defn filter f l = {
+    case l of {
+        Nil -> { Nil }
+        Cons x xs -> { if (f x) (Cons x (filter f xs)) (filter f xs) }
+    }
+}
+
+defn map f l = {
+    case l of {
+        Nil -> { Nil }
+        Cons x xs -> { Cons (f x) (map f xs) }
+    }
+}
+
+defn nats = {
+    Cons (S (S O)) (map S nats)
+}
+
+defn primesRec l = {
+    case l of {
+        Nil -> { Nil }
+        Cons p xs -> { Cons p (primesRec (filter (notDivisibleBy p) xs)) }
+    }
+}
+
+defn primes = {
+    primesRec nats
+}
+
+defn take n l = {
+    case l of {
+        Nil -> { Nil }
+        Cons x xs -> {
+            case n of {
+                O -> { Nil }
+                S np -> { Cons x (take np xs) }
+            }
+        }
+    }
+}
+
+defn head l = {
+    case l of {
+        Nil -> { O }
+        Cons x xs -> { x }
+    }
+}
+
+defn reverseAcc a l = {
+    case l of {
+        Nil -> { a }
+        Cons x xs -> { reverseAcc (Cons x a) xs }
+    }
+}
+
+defn reverse l = {
+    reverseAcc Nil l
+}
+
+defn main = {
+    toInt (head (reverse (take ((S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S (S O))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) primes)))
+}
--- a/code/compiler/12/examples/runtime1.c
+++ b/code/compiler/12/examples/runtime1.c
@@ -0,0 +1,31 @@
+#include "../runtime.h"
+
+void f_add(struct stack* s) {
+    struct node_num* left = (struct node_num*) eval(stack_peek(s, 0));
+    struct node_num* right = (struct node_num*) eval(stack_peek(s, 1));
+    stack_push(s, (struct node_base*) alloc_num(left->value + right->value));
+}
+
+void f_main(struct stack* s) {
+    // PushInt 320
+    stack_push(s, (struct node_base*) alloc_num(320));
+
+    // PushInt 6
+    stack_push(s, (struct node_base*) alloc_num(6));
+
+    // PushGlobal f_add (the function for +)
+    stack_push(s, (struct node_base*) alloc_global(f_add, 2));
+
+    struct node_base* left;
+    struct node_base* right;
+    
+    // MkApp
+    left = stack_pop(s);
+    right = stack_pop(s);
+    stack_push(s, (struct node_base*) alloc_app(left, right));
+    
+    // MkApp
+    left = stack_pop(s);
+    right = stack_pop(s);
+    stack_push(s, (struct node_base*) alloc_app(left, right));
+}
--- a/code/compiler/12/examples/works1.txt
+++ b/code/compiler/12/examples/works1.txt
@@ -0,0 +1,2 @@
+defn main = { sum 320 6 }
+defn sum x y = { x + y }
--- a/code/compiler/12/examples/works2.txt
+++ b/code/compiler/12/examples/works2.txt
@@ -0,0 +1,3 @@
+defn add x y = { x + y }
+defn double x = { add x x }
+defn main = { double 163 }
--- a/code/compiler/12/examples/works3.txt
+++ b/code/compiler/12/examples/works3.txt
@@ -0,0 +1,9 @@
+data List a = { Nil, Cons a (List a) }
+data Bool = { True, False }
+defn length l = {
+    case l of {
+        Nil -> { 0 }
+        Cons x xs -> { 1 + length xs }
+    }
+}
+defn main = { length (Cons 1 (Cons 2 (Cons 3 Nil))) + length (Cons True (Cons False (Cons True Nil))) }
--- a/code/compiler/12/examples/works4.txt
+++ b/code/compiler/12/examples/works4.txt
@@ -0,0 +1,16 @@
+data List = { Nil, Cons Int List }
+
+defn add x y = { x + y }
+defn mul x y = { x * y }
+
+defn foldr f b l = {
+    case l of {
+        Nil -> { b }
+        Cons x xs -> { f x (foldr f b xs) }
+    }
+}
+
+defn main = {
+    foldr add 0 (Cons 1 (Cons 2 (Cons 3 (Cons 4 Nil)))) +
+    foldr mul 1 (Cons 1 (Cons 2 (Cons 3 (Cons 4 Nil))))
+}
--- a/code/compiler/12/examples/works5.txt
+++ b/code/compiler/12/examples/works5.txt
@@ -0,0 +1,17 @@
+data List = { Nil, Cons Int List }
+
+defn sumZip l m = {
+    case l of {
+        Nil -> { 0 }
+        Cons x xs -> {
+            case m of {
+                Nil -> { 0 }
+                Cons y ys -> { x + y + sumZip xs ys }
+            }
+        }
+    }
+}
+
+defn ones = { Cons 1 ones }
+
+defn main = { sumZip ones (Cons 1 (Cons 2 (Cons 3 Nil))) }
--- a/code/compiler/12/global_scope.cpp
+++ b/code/compiler/12/global_scope.cpp
@@ -0,0 +1,83 @@
+#include "global_scope.hpp"
+#include "ast.hpp"
+
+void global_function::compile() {
+    env_ptr new_env = env_ptr(new env_offset(0, nullptr));
+    for(auto it = params.rbegin(); it != params.rend(); it++) {
+        new_env = env_ptr(new env_var(*it, new_env));
+    }
+    body->compile(new_env, instructions);
+    instructions.push_back(instruction_ptr(new instruction_update(params.size())));
+    instructions.push_back(instruction_ptr(new instruction_pop(params.size())));
+}
+
+void global_function::declare_llvm(llvm_context& ctx) {
+    generated_function = ctx.create_custom_function(name, params.size());
+}
+
+void global_function::generate_llvm(llvm_context& ctx) {
+    ctx.builder.SetInsertPoint(&generated_function->getEntryBlock());
+    for(auto& instruction : instructions) {
+        instruction->gen_llvm(ctx, generated_function);
+    }
+    ctx.builder.CreateRetVoid();
+}
+
+void global_constructor::generate_llvm(llvm_context& ctx) {
+    auto new_function =
+        ctx.create_custom_function(name, arity);
+    std::vector<instruction_ptr> instructions;
+    instructions.push_back(instruction_ptr(new instruction_pack(tag, arity)));
+    instructions.push_back(instruction_ptr(new instruction_update(0)));
+    ctx.builder.SetInsertPoint(&new_function->getEntryBlock());
+    for (auto& instruction : instructions) {
+        instruction->gen_llvm(ctx, new_function);
+    }
+    ctx.builder.CreateRetVoid();
+}
+
+global_function& global_scope::add_function(std::string n, std::vector<std::string> ps, ast_ptr b) {
+    global_function* new_function = new global_function(mangle_name(n), std::move(ps), std::move(b));
+    functions.push_back(global_function_ptr(new_function));
+    return *new_function;
+}
+
+global_constructor& global_scope::add_constructor(std::string n, int8_t t, size_t a) {
+    global_constructor* new_constructor = new global_constructor(mangle_name(n), t, a);
+    constructors.push_back(global_constructor_ptr(new_constructor));
+    return *new_constructor;
+}
+
+void global_scope::compile() {
+    for(auto& function : functions) {
+        function->compile();
+    }
+}
+
+void global_scope::generate_llvm(llvm_context& ctx) {
+    for(auto& constructor : constructors) {
+        constructor->generate_llvm(ctx);
+    }
+    for(auto& function : functions) {
+        function->declare_llvm(ctx);
+    }
+    for(auto& function : functions) {
+        function->generate_llvm(ctx);
+    }
+}
+
+std::string global_scope::mangle_name(const std::string& n) {
+    auto occurence_it = occurence_count.find(n);
+    int occurence = 0;
+    if(occurence_it != occurence_count.end()) {
+        occurence = occurence_it->second + 1;
+    }
+    occurence_count[n] = occurence;
+
+    std::string final_name = n;
+    if (occurence != 0) {
+        final_name += "_";
+        final_name += std::to_string(occurence);
+    }
+    return final_name;
+}
--- a/code/compiler/12/global_scope.hpp
+++ b/code/compiler/12/global_scope.hpp
@@ -0,0 +1,55 @@
+#pragma once
+#include <memory>
+#include <string>
+#include <vector>
+#include <llvm/IR/Function.h>
+#include "instruction.hpp"
+
+struct ast;
+using ast_ptr = std::unique_ptr<ast>;
+
+struct global_function {
+    std::string name;
+    std::vector<std::string> params;
+    ast_ptr body;
+
+    std::vector<instruction_ptr> instructions;
+    llvm::Function* generated_function;
+
+    global_function(std::string n, std::vector<std::string> ps, ast_ptr b)
+        : name(std::move(n)), params(std::move(ps)), body(std::move(b)) {}
+
+    void compile();
+    void declare_llvm(llvm_context& ctx);
+    void generate_llvm(llvm_context& ctx);
+};
+
+using global_function_ptr = std::unique_ptr<global_function>;
+
+struct global_constructor {
+    std::string name;
+    int8_t tag;
+    size_t arity;
+
+    global_constructor(std::string n, int8_t t, size_t a)
+        : name(std::move(n)), tag(t), arity(a) {}
+
+    void generate_llvm(llvm_context& ctx);
+};
+
+using global_constructor_ptr = std::unique_ptr<global_constructor>;
+
+struct global_scope {
+    std::map<std::string, int> occurence_count;
+    std::vector<global_function_ptr> functions;
+    std::vector<global_constructor_ptr> constructors;
+
+    global_function& add_function(std::string n, std::vector<std::string> ps, ast_ptr b);
+    global_constructor& add_constructor(std::string n, int8_t t, size_t a);
+
+    void compile();
+    void generate_llvm(llvm_context& ctx);
+
+    private:
+    std::string mangle_name(const std::string& n);
+};
--- a/code/compiler/12/graph.cpp
+++ b/code/compiler/12/graph.cpp
@@ -0,0 +1,114 @@
+#include "graph.hpp"
+
+std::set<function_graph::edge> function_graph::compute_transitive_edges() {
+    std::set<edge> transitive_edges;
+    transitive_edges.insert(edges.begin(), edges.end());
+    for(auto& connector : adjacency_lists) {
+        for(auto& from : adjacency_lists) {
+            edge to_connector { from.first, connector.first };
+            for(auto& to : adjacency_lists) {
+                edge full_jump { from.first, to.first };
+                if(transitive_edges.find(full_jump) != transitive_edges.end()) continue;
+
+                edge from_connector { connector.first, to.first };
+                if(transitive_edges.find(to_connector) != transitive_edges.end() &&
+                        transitive_edges.find(from_connector) != transitive_edges.end())
+                    transitive_edges.insert(std::move(full_jump));
+            }
+        }
+    }
+    return transitive_edges;
+}
+
+void function_graph::create_groups(
+        const std::set<edge>& transitive_edges,
+        std::map<function, group_id>& group_ids,
+        std::map<group_id, data_ptr>& group_data_map) {
+    group_id id_counter = 0;
+    for(auto& vertex : adjacency_lists) {
+        if(group_ids.find(vertex.first) != group_ids.end())
+            continue;
+        data_ptr new_group(new group_data);
+        new_group->functions.insert(vertex.first);
+        group_data_map[id_counter] = new_group;
+        group_ids[vertex.first] = id_counter;
+        for(auto& other_vertex : adjacency_lists) {
+            if(transitive_edges.find({vertex.first, other_vertex.first}) != transitive_edges.end() &&
+                    transitive_edges.find({other_vertex.first, vertex.first}) != transitive_edges.end()) {
+                group_ids[other_vertex.first] = id_counter;
+                new_group->functions.insert(other_vertex.first);
+            }
+        }
+        id_counter++;
+    }
+}
+
+void function_graph::create_edges(
+        std::map<function, group_id>& group_ids,
+        std::map<group_id, data_ptr>& group_data_map) {
+    std::set<std::pair<group_id, group_id>> group_edges;
+    for(auto& vertex : adjacency_lists) {
+        auto vertex_id = group_ids[vertex.first];
+        auto& vertex_data = group_data_map[vertex_id];
+        for(auto& other_vertex : vertex.second) {
+            auto other_id = group_ids[other_vertex];
+            if(vertex_id == other_id) continue;
+            if(group_edges.find({vertex_id, other_id}) != group_edges.end())
+                continue;
+            group_edges.insert({vertex_id, other_id});
+            vertex_data->adjacency_list.insert(other_id);
+            group_data_map[other_id]->indegree++;
+        }
+    }
+}
+
+std::vector<group_ptr> function_graph::generate_order(
+        std::map<function, group_id>& group_ids,
+        std::map<group_id, data_ptr>& group_data_map) {
+    std::queue<group_id> id_queue;
+    std::vector<group_ptr> output;
+    for(auto& group : group_data_map) {
+        if(group.second->indegree == 0) id_queue.push(group.first);
+    }
+
+    while(!id_queue.empty()) {
+        auto new_id = id_queue.front();
+        auto& group_data = group_data_map[new_id];
+        group_ptr output_group(new group);
+        output_group->members = std::move(group_data->functions);
+        id_queue.pop();
+
+        for(auto& adjacent_group : group_data->adjacency_list) {
+            if(--group_data_map[adjacent_group]->indegree == 0)
+                id_queue.push(adjacent_group);
+        }
+
+        output.push_back(std::move(output_group));
+    }
+
+    return output;
+}
+
+std::set<function>& function_graph::add_function(const function& f) {
+    auto adjacency_list_it = adjacency_lists.find(f);
+    if(adjacency_list_it != adjacency_lists.end()) {
+        return adjacency_list_it->second;
+    } else {
+        return adjacency_lists[f] = { };
+    }
+}
+
+void function_graph::add_edge(const function& from, const function& to) {
+    add_function(from).insert(to);
+    edges.insert({ from, to });
+}
+
+std::vector<group_ptr> function_graph::compute_order() {
+    std::set<edge> transitive_edges = compute_transitive_edges();
+    std::map<function, group_id> group_ids;
+    std::map<group_id, data_ptr> group_data_map;
+
+    create_groups(transitive_edges, group_ids, group_data_map);
+    create_edges(group_ids, group_data_map);
+    return generate_order(group_ids, group_data_map);
+}
--- a/code/compiler/12/graph.hpp
+++ b/code/compiler/12/graph.hpp
@@ -0,0 +1,51 @@
+#pragma once
+#include <algorithm>
+#include <cstddef>
+#include <queue>
+#include <set>
+#include <string>
+#include <map>
+#include <memory>
+#include <vector>
+
+using function = std::string;
+
+struct group {
+    std::set<function> members;
+};
+
+using group_ptr = std::unique_ptr<group>;
+
+class function_graph {
+    using group_id = size_t;
+
+    struct group_data {
+        std::set<function> functions;
+        std::set<group_id> adjacency_list;
+        size_t indegree;
+    };
+
+    using data_ptr = std::shared_ptr<group_data>;
+    using edge = std::pair<function, function>;
+    using group_edge = std::pair<group_id, group_id>;
+
+    std::map<function, std::set<function>> adjacency_lists;
+    std::set<edge> edges;
+
+    std::set<edge> compute_transitive_edges();
+    void create_groups(
+            const std::set<edge>&,
+            std::map<function, group_id>&,
+            std::map<group_id, data_ptr>&);
+    void create_edges(
+            std::map<function, group_id>&,
+            std::map<group_id, data_ptr>&);
+    std::vector<group_ptr> generate_order(
+            std::map<function, group_id>&,
+            std::map<group_id, data_ptr>&);
+    
+    public:
+    std::set<function>& add_function(const function& f);
+    void add_edge(const function& from, const function& to);
+    std::vector<group_ptr> compute_order();
+};
--- a/code/compiler/12/instruction.cpp
+++ b/code/compiler/12/instruction.cpp
@@ -0,0 +1,177 @@
+#include "instruction.hpp"
+#include "llvm_context.hpp"
+#include <llvm/IR/BasicBlock.h>
+#include <llvm/IR/Function.h>
+
+using namespace llvm;
+
+static void print_indent(int n, std::ostream& to) {
+    while(n--) to << "  ";
+}
+
+void instruction_pushint::print(int indent, std::ostream& to) const {
+    print_indent(indent, to);
+    to << "PushInt(" << value << ")" << std::endl;
+}
+
+void instruction_pushint::gen_llvm(llvm_context& ctx, Function* f) const {
+    ctx.create_push(f, ctx.create_num(f, ctx.create_i32(value)));
+}
+
+void instruction_pushglobal::print(int indent, std::ostream& to) const {
+    print_indent(indent, to);
+    to << "PushGlobal(" << name << ")" << std::endl;
+}
+
+void instruction_pushglobal::gen_llvm(llvm_context& ctx, Function* f) const {
+    auto& global_f = ctx.custom_functions.at("f_" + name);
+    auto arity = ctx.create_i32(global_f->arity);
+    ctx.create_push(f, ctx.create_global(f, global_f->function, arity));
+}
+
+void instruction_push::print(int indent, std::ostream& to) const {
+    print_indent(indent, to);
+    to << "Push(" << offset << ")" << std::endl;
+}
+
+void instruction_push::gen_llvm(llvm_context& ctx, Function* f) const {
+    ctx.create_push(f, ctx.create_peek(f, ctx.create_size(offset)));
+}
+
+void instruction_pop::print(int indent, std::ostream& to) const {
+    print_indent(indent, to);
+    to << "Pop(" << count << ")" << std::endl;
+}
+
+void instruction_pop::gen_llvm(llvm_context& ctx, Function* f) const {
+    ctx.create_popn(f, ctx.create_size(count));
+}
+
+void instruction_mkapp::print(int indent, std::ostream& to) const {
+    print_indent(indent, to);
+    to << "MkApp()" << std::endl;
+}
+
+void instruction_mkapp::gen_llvm(llvm_context& ctx, Function* f) const {
+    auto left = ctx.create_pop(f);
+    auto right = ctx.create_pop(f);
+    ctx.create_push(f, ctx.create_app(f, left, right));
+}
+
+void instruction_update::print(int indent, std::ostream& to) const {
+    print_indent(indent, to);
+    to << "Update(" << offset << ")" << std::endl;
+}
+
+void instruction_update::gen_llvm(llvm_context& ctx, Function* f) const {
+    ctx.create_update(f, ctx.create_size(offset));
+}
+
+void instruction_pack::print(int indent, std::ostream& to) const {
+    print_indent(indent, to);
+    to << "Pack(" << tag << ", " << size << ")" << std::endl;
+}
+
+void instruction_pack::gen_llvm(llvm_context& ctx, Function* f) const {
+    ctx.create_pack(f, ctx.create_size(size), ctx.create_i8(tag));
+}
+
+void instruction_split::print(int indent, std::ostream& to) const {
+    print_indent(indent, to);
+    to << "Split()" << std::endl;
+}
+
+void instruction_split::gen_llvm(llvm_context& ctx, Function* f) const {
+    ctx.create_split(f, ctx.create_size(size));
+}
+
+void instruction_jump::print(int indent, std::ostream& to) const {
+    print_indent(indent, to);
+    to << "Jump(" << std::endl;
+    for(auto& instruction_set : branches) {
+        for(auto& instruction : instruction_set) {
+            instruction->print(indent + 2, to);
+        }
+        to << std::endl;
+    }
+    print_indent(indent, to);
+    to << ")" << std::endl;
+}
+
+void instruction_jump::gen_llvm(llvm_context& ctx, Function* f) const {
+    auto top_node = ctx.create_peek(f, ctx.create_size(0));
+    auto tag = ctx.unwrap_data_tag(top_node);
+    auto safety_block = BasicBlock::Create(ctx.ctx, "safety", f);
+    auto switch_op = ctx.builder.CreateSwitch(tag, safety_block, tag_mappings.size());
+    std::vector<BasicBlock*> blocks;
+
+    for(auto& branch : branches) {
+        auto branch_block = BasicBlock::Create(ctx.ctx, "branch", f);
+        ctx.builder.SetInsertPoint(branch_block);
+        for(auto& instruction : branch) {
+            instruction->gen_llvm(ctx, f);
+        }
+        ctx.builder.CreateBr(safety_block);
+        blocks.push_back(branch_block);
+    }
+
+    for(auto& mapping : tag_mappings) {
+        switch_op->addCase(ctx.create_i8(mapping.first), blocks[mapping.second]);
+    }
+
+    ctx.builder.SetInsertPoint(safety_block);
+}
+
+void instruction_slide::print(int indent, std::ostream& to) const {
+    print_indent(indent, to);
+    to << "Slide(" << offset << ")" << std::endl;
+}
+
+void instruction_slide::gen_llvm(llvm_context& ctx, Function* f) const {
+    ctx.create_slide(f, ctx.create_size(offset));
+}
+
+void instruction_binop::print(int indent, std::ostream& to) const {
+    print_indent(indent, to);
+    to << "BinOp(" << op_action(op) << ")" << std::endl;
+}
+
+void instruction_binop::gen_llvm(llvm_context& ctx, Function* f) const {
+    auto left_int = ctx.unwrap_num(ctx.create_pop(f));
+    auto right_int = ctx.unwrap_num(ctx.create_pop(f));
+    llvm::Value* result;
+    switch(op) {
+        case PLUS: result = ctx.builder.CreateAdd(left_int, right_int); break;
+        case MINUS: result = ctx.builder.CreateSub(left_int, right_int); break;
+        case TIMES: result = ctx.builder.CreateMul(left_int, right_int); break;
+        case DIVIDE: result = ctx.builder.CreateSDiv(left_int, right_int); break;
+    }
+    ctx.create_push(f, ctx.create_num(f, result));
+}
+
+void instruction_eval::print(int indent, std::ostream& to) const {
+    print_indent(indent, to);
+    to << "Eval()" << std::endl;
+}
+
+void instruction_eval::gen_llvm(llvm_context& ctx, Function* f) const {
+    ctx.create_unwind(f);
+}
+
+void instruction_alloc::print(int indent, std::ostream& to) const {
+    print_indent(indent, to);
+    to << "Alloc(" << amount << ")" << std::endl;
+}
+
+void instruction_alloc::gen_llvm(llvm_context& ctx, Function* f) const {
+    ctx.create_alloc(f, ctx.create_size(amount));
+}
+
+void instruction_unwind::print(int indent, std::ostream& to) const {
+    print_indent(indent, to);
+    to << "Unwind()" << std::endl;
+}
+
+void instruction_unwind::gen_llvm(llvm_context& ctx, Function* f) const {
+    // Nothing
+}
--- a/code/compiler/12/instruction.hpp
+++ b/code/compiler/12/instruction.hpp
@@ -0,0 +1,142 @@
+#pragma once
+#include <llvm/IR/Function.h>
+#include <string>
+#include <memory>
+#include <vector>
+#include <map>
+#include <ostream>
+#include "binop.hpp"
+#include "llvm_context.hpp"
+
+struct instruction {
+    virtual ~instruction() = default;
+
+    virtual void print(int indent, std::ostream& to) const = 0;
+    virtual void gen_llvm(llvm_context& ctx, llvm::Function* f) const = 0;
+};
+
+using instruction_ptr = std::unique_ptr<instruction>;
+
+struct instruction_pushint : public instruction {
+    int value;
+
+    instruction_pushint(int v)
+        : value(v) {}
+
+    void print(int indent, std::ostream& to) const;
+    void gen_llvm(llvm_context& ctx, llvm::Function* f) const;
+};
+
+struct instruction_pushglobal : public instruction {
+    std::string name;
+
+    instruction_pushglobal(std::string n)
+        : name(std::move(n)) {}
+
+    void print(int indent, std::ostream& to) const;
+    void gen_llvm(llvm_context& ctx, llvm::Function* f) const;
+};
+
+struct instruction_push : public instruction {
+    int offset;
+
+    instruction_push(int o)
+        : offset(o) {}
+
+    void print(int indent, std::ostream& to) const;
+    void gen_llvm(llvm_context& ctx, llvm::Function* f) const;
+};
+
+struct instruction_pop : public instruction {
+    int count;
+
+    instruction_pop(int c)
+        : count(c) {}
+
+    void print(int indent, std::ostream& to) const;
+    void gen_llvm(llvm_context& ctx, llvm::Function* f) const;
+};
+
+struct instruction_mkapp : public instruction {
+    void print(int indent, std::ostream& to) const;
+    void gen_llvm(llvm_context& ctx, llvm::Function* f) const;
+};
+
+struct instruction_update : public instruction {
+    int offset;
+
+    instruction_update(int o)
+        : offset(o) {}
+
+    void print(int indent, std::ostream& to) const;
+    void gen_llvm(llvm_context& ctx, llvm::Function* f) const;
+};
+
+struct instruction_pack : public instruction {
+    int tag;
+    int size;
+
+    instruction_pack(int t, int s)
+        : tag(t), size(s) {}
+
+    void print(int indent, std::ostream& to) const;
+    void gen_llvm(llvm_context& ctx, llvm::Function* f) const;
+};
+
+struct instruction_split : public instruction {
+    int size;
+
+    instruction_split(int s)
+        : size(s) {}
+
+    void print(int indent, std::ostream& to) const;
+    void gen_llvm(llvm_context& ctx, llvm::Function* f) const;
+};
+
+struct instruction_jump : public instruction {
+    std::vector<std::vector<instruction_ptr>> branches;
+    std::map<int, int> tag_mappings;
+
+    void print(int indent, std::ostream& to) const;
+    void gen_llvm(llvm_context& ctx, llvm::Function* f) const;
+};
+
+struct instruction_slide : public instruction {
+    int offset;
+
+    instruction_slide(int o)
+        : offset(o) {}
+
+    void print(int indent, std::ostream& to) const;
+    void gen_llvm(llvm_context& ctx, llvm::Function* f) const;
+};
+
+struct instruction_binop : public instruction {
+    binop op;
+
+    instruction_binop(binop o)
+        : op(o) {}
+
+    void print(int indent, std::ostream& to) const;
+    void gen_llvm(llvm_context& ctx, llvm::Function* f) const;
+};
+
+struct instruction_eval : public instruction {
+    void print(int indent, std::ostream& to) const;
+    void gen_llvm(llvm_context& ctx, llvm::Function* f) const;
+};
+
+struct instruction_alloc : public instruction {
+    int amount;
+
+    instruction_alloc(int a)
+        : amount(a) {}
+
+    void print(int indent, std::ostream& to) const;
+    void gen_llvm(llvm_context& ctx, llvm::Function* f) const;
+};
+
+struct instruction_unwind : public instruction {
+    void print(int indent, std::ostream& to) const;
+    void gen_llvm(llvm_context& ctx, llvm::Function* f) const;
+};
--- a/code/compiler/12/llvm_context.cpp
+++ b/code/compiler/12/llvm_context.cpp
@@ -0,0 +1,278 @@
+#include "llvm_context.hpp"
+#include <llvm/IR/DerivedTypes.h>
+
+using namespace llvm;
+
+void llvm_context::create_types() {
+    stack_type = StructType::create(ctx, "stack");
+    gmachine_type = StructType::create(ctx, "gmachine");
+    stack_ptr_type = PointerType::getUnqual(stack_type);
+    gmachine_ptr_type = PointerType::getUnqual(gmachine_type);
+    tag_type = IntegerType::getInt8Ty(ctx);
+    struct_types["node_base"] = StructType::create(ctx, "node_base");
+    struct_types["node_app"] = StructType::create(ctx, "node_app");
+    struct_types["node_num"] = StructType::create(ctx, "node_num");
+    struct_types["node_global"] = StructType::create(ctx, "node_global");
+    struct_types["node_ind"] = StructType::create(ctx, "node_ind");
+    struct_types["node_data"] = StructType::create(ctx, "node_data");
+    node_ptr_type = PointerType::getUnqual(struct_types.at("node_base"));
+    function_type = FunctionType::get(Type::getVoidTy(ctx), { gmachine_ptr_type }, false);
+
+    gmachine_type->setBody(
+            stack_ptr_type,
+            node_ptr_type,
+            IntegerType::getInt64Ty(ctx),
+            IntegerType::getInt64Ty(ctx)
+    );
+    struct_types.at("node_base")->setBody(
+            IntegerType::getInt32Ty(ctx),
+            IntegerType::getInt8Ty(ctx),
+            node_ptr_type
+    );
+    struct_types.at("node_app")->setBody(
+            struct_types.at("node_base"),
+            node_ptr_type,
+            node_ptr_type
+    );
+    struct_types.at("node_num")->setBody(
+            struct_types.at("node_base"),
+            IntegerType::getInt32Ty(ctx)
+    );
+    struct_types.at("node_global")->setBody(
+            struct_types.at("node_base"),
+            FunctionType::get(Type::getVoidTy(ctx), { stack_ptr_type }, false)
+    );
+    struct_types.at("node_ind")->setBody(
+            struct_types.at("node_base"),
+            node_ptr_type
+    );
+    struct_types.at("node_data")->setBody(
+            struct_types.at("node_base"),
+            IntegerType::getInt8Ty(ctx),
+            PointerType::getUnqual(node_ptr_type)
+    );
+}
+
+void llvm_context::create_functions() {
+    auto void_type = Type::getVoidTy(ctx);
+    auto sizet_type = IntegerType::get(ctx, sizeof(size_t) * 8);
+    functions["stack_init"] = Function::Create(
+            FunctionType::get(void_type, { stack_ptr_type }, false),
+            Function::LinkageTypes::ExternalLinkage,
+            "stack_init",
+            &module
+    );
+    functions["stack_free"] = Function::Create(
+            FunctionType::get(void_type, { stack_ptr_type }, false),
+            Function::LinkageTypes::ExternalLinkage,
+            "stack_free",
+            &module
+    );
+    functions["stack_push"] = Function::Create(
+            FunctionType::get(void_type, { stack_ptr_type, node_ptr_type }, false),
+            Function::LinkageTypes::ExternalLinkage,
+            "stack_push",
+            &module
+    );
+    functions["stack_pop"] = Function::Create(
+            FunctionType::get(node_ptr_type, { stack_ptr_type }, false),
+            Function::LinkageTypes::ExternalLinkage,
+            "stack_pop",
+            &module
+    );
+    functions["stack_peek"] = Function::Create(
+            FunctionType::get(node_ptr_type, { stack_ptr_type, sizet_type }, false),
+            Function::LinkageTypes::ExternalLinkage,
+            "stack_peek",
+            &module
+    );
+    functions["stack_popn"] = Function::Create(
+            FunctionType::get(void_type, { stack_ptr_type, sizet_type }, false),
+            Function::LinkageTypes::ExternalLinkage,
+            "stack_popn",
+            &module
+    );
+    functions["gmachine_slide"] = Function::Create(
+            FunctionType::get(void_type, { gmachine_ptr_type, sizet_type }, false),
+            Function::LinkageTypes::ExternalLinkage,
+            "gmachine_slide",
+            &module
+    );
+    functions["gmachine_update"] = Function::Create(
+            FunctionType::get(void_type, { gmachine_ptr_type, sizet_type }, false),
+            Function::LinkageTypes::ExternalLinkage,
+            "gmachine_update",
+            &module
+    );
+    functions["gmachine_alloc"] = Function::Create(
+            FunctionType::get(void_type, { gmachine_ptr_type, sizet_type }, false),
+            Function::LinkageTypes::ExternalLinkage,
+            "gmachine_alloc",
+            &module
+    );
+    functions["gmachine_pack"] = Function::Create(
+            FunctionType::get(void_type, { gmachine_ptr_type, sizet_type, tag_type }, false),
+            Function::LinkageTypes::ExternalLinkage,
+            "gmachine_pack",
+            &module
+    );
+    functions["gmachine_split"] = Function::Create(
+            FunctionType::get(void_type, { gmachine_ptr_type, sizet_type }, false),
+            Function::LinkageTypes::ExternalLinkage,
+            "gmachine_split",
+            &module
+    );
+    functions["gmachine_track"] = Function::Create(
+            FunctionType::get(node_ptr_type, { gmachine_ptr_type, node_ptr_type }, false),
+            Function::LinkageTypes::ExternalLinkage,
+            "gmachine_track",
+            &module
+    );
+
+    auto int32_type = IntegerType::getInt32Ty(ctx);
+    functions["alloc_app"] = Function::Create(
+            FunctionType::get(node_ptr_type, { node_ptr_type, node_ptr_type }, false),
+            Function::LinkageTypes::ExternalLinkage,
+            "alloc_app",
+            &module
+    );
+    functions["alloc_num"] = Function::Create(
+            FunctionType::get(node_ptr_type, { int32_type }, false),
+            Function::LinkageTypes::ExternalLinkage,
+            "alloc_num",
+            &module
+    );
+    functions["alloc_global"] = Function::Create(
+            FunctionType::get(node_ptr_type, { function_type, int32_type }, false),
+            Function::LinkageTypes::ExternalLinkage,
+            "alloc_global",
+            &module
+    );
+    functions["alloc_ind"] = Function::Create(
+            FunctionType::get(node_ptr_type, { node_ptr_type }, false),
+            Function::LinkageTypes::ExternalLinkage,
+            "alloc_ind",
+            &module
+    );
+
+    functions["unwind"] = Function::Create(
+            FunctionType::get(void_type, { gmachine_ptr_type }, false),
+            Function::LinkageTypes::ExternalLinkage,
+            "unwind",
+            &module
+    );
+}
+
+ConstantInt* llvm_context::create_i8(int8_t i) {
+    return ConstantInt::get(ctx, APInt(8, i));
+}
+ConstantInt* llvm_context::create_i32(int32_t i) {
+    return ConstantInt::get(ctx, APInt(32, i));
+}
+ConstantInt* llvm_context::create_size(size_t i) {
+    return ConstantInt::get(ctx, APInt(sizeof(size_t) * 8, i));
+}
+
+Value* llvm_context::create_pop(Function* f) {
+    auto pop_f = functions.at("stack_pop");
+    return builder.CreateCall(pop_f, { unwrap_gmachine_stack_ptr(f->arg_begin()) });
+}
+Value* llvm_context::create_peek(Function* f, Value* off) {
+    auto peek_f = functions.at("stack_peek");
+    return builder.CreateCall(peek_f, { unwrap_gmachine_stack_ptr(f->arg_begin()), off });
+}
+void llvm_context::create_push(Function* f, Value* v) {
+    auto push_f = functions.at("stack_push");
+    builder.CreateCall(push_f, { unwrap_gmachine_stack_ptr(f->arg_begin()), v });
+}
+void llvm_context::create_popn(Function* f, Value* off) {
+    auto popn_f = functions.at("stack_popn");
+    builder.CreateCall(popn_f, { unwrap_gmachine_stack_ptr(f->arg_begin()), off });
+}
+void llvm_context::create_update(Function* f, Value* off) {
+    auto update_f = functions.at("gmachine_update");
+    builder.CreateCall(update_f, { f->arg_begin(), off });
+}
+void llvm_context::create_pack(Function* f, Value* c, Value* t) {
+    auto pack_f = functions.at("gmachine_pack");
+    builder.CreateCall(pack_f, { f->arg_begin(), c, t });
+}
+void llvm_context::create_split(Function* f, Value* c) {
+    auto split_f = functions.at("gmachine_split");
+    builder.CreateCall(split_f, { f->arg_begin(), c });
+}
+void llvm_context::create_slide(Function* f, Value* off) {
+    auto slide_f = functions.at("gmachine_slide");
+    builder.CreateCall(slide_f, { f->arg_begin(), off });
+}
+void llvm_context::create_alloc(Function* f, Value* n) {
+    auto alloc_f = functions.at("gmachine_alloc");
+    builder.CreateCall(alloc_f, { f->arg_begin(), n });
+}
+Value* llvm_context::create_track(Function* f, Value* v) {
+    auto track_f = functions.at("gmachine_track");
+    return builder.CreateCall(track_f, { f->arg_begin(), v });
+}
+
+void llvm_context::create_unwind(Function* f) {
+    auto unwind_f = functions.at("unwind");
+    builder.CreateCall(unwind_f, { f->args().begin() });
+}
+
+Value* llvm_context::unwrap_gmachine_stack_ptr(Value* g) {
+    auto offset_0 = create_i32(0);
+    return builder.CreateGEP(g, { offset_0, offset_0 });
+}
+
+Value* llvm_context::unwrap_num(Value* v) {
+    auto num_ptr_type = PointerType::getUnqual(struct_types.at("node_num"));
+    auto cast = builder.CreatePointerCast(v, num_ptr_type);
+    auto offset_0 = create_i32(0);
+    auto offset_1 = create_i32(1);
+    auto int_ptr = builder.CreateGEP(cast, { offset_0, offset_1 });
+    return builder.CreateLoad(int_ptr);
+}
+Value* llvm_context::create_num(Function* f, Value* v) {
+    auto alloc_num_f = functions.at("alloc_num");
+    auto alloc_num_call = builder.CreateCall(alloc_num_f, { v });
+    return create_track(f, alloc_num_call);
+}
+
+Value* llvm_context::unwrap_data_tag(Value* v) {
+    auto data_ptr_type = PointerType::getUnqual(struct_types.at("node_data"));
+    auto cast = builder.CreatePointerCast(v, data_ptr_type);
+    auto offset_0 = create_i32(0);
+    auto offset_1 = create_i32(1);
+    auto tag_ptr = builder.CreateGEP(cast, { offset_0, offset_1 });
+    return builder.CreateLoad(tag_ptr);
+}
+
+Value* llvm_context::create_global(Function* f, Value* gf, Value* a) {
+    auto alloc_global_f = functions.at("alloc_global");
+    auto alloc_global_call = builder.CreateCall(alloc_global_f, { gf, a });
+    return create_track(f, alloc_global_call);
+}
+
+Value* llvm_context::create_app(Function* f, Value* l, Value* r) {
+    auto alloc_app_f = functions.at("alloc_app");
+    auto alloc_app_call = builder.CreateCall(alloc_app_f, { l, r });
+    return create_track(f, alloc_app_call);
+}
+
+llvm::Function* llvm_context::create_custom_function(std::string name, int32_t arity) {
+    auto void_type = llvm::Type::getVoidTy(ctx);
+    auto new_function = llvm::Function::Create(
+            function_type,
+            llvm::Function::LinkageTypes::ExternalLinkage,
+            "f_" + name,
+            &module
+    );
+    auto start_block = llvm::BasicBlock::Create(ctx, "entry", new_function);
+
+    auto new_custom_f = custom_function_ptr(new custom_function());
+    new_custom_f->arity = arity;
+    new_custom_f->function = new_function;
+    custom_functions["f_" + name] = std::move(new_custom_f);
+
+    return new_function;
+}
--- a/code/compiler/12/llvm_context.hpp
+++ b/code/compiler/12/llvm_context.hpp
@@ -0,0 +1,72 @@
+#pragma once
+#include <llvm/IR/DerivedTypes.h>
+#include <llvm/IR/Function.h>
+#include <llvm/IR/LLVMContext.h>
+#include <llvm/IR/IRBuilder.h>
+#include <llvm/IR/Module.h>
+#include <llvm/IR/Value.h>
+#include <map>
+
+struct llvm_context {
+    struct custom_function {
+        llvm::Function* function;
+        int32_t arity;
+    };
+
+    using custom_function_ptr = std::unique_ptr<custom_function>;
+
+    llvm::LLVMContext ctx;
+    llvm::IRBuilder<> builder;
+    llvm::Module module;
+
+    std::map<std::string, custom_function_ptr> custom_functions;
+    std::map<std::string, llvm::Function*> functions;
+    std::map<std::string, llvm::StructType*> struct_types;
+
+    llvm::StructType* stack_type;
+    llvm::StructType* gmachine_type;
+    llvm::PointerType* stack_ptr_type;
+    llvm::PointerType* gmachine_ptr_type;
+    llvm::PointerType* node_ptr_type;
+    llvm::IntegerType* tag_type;
+    llvm::FunctionType* function_type;
+
+    llvm_context()
+        : builder(ctx), module("bloglang", ctx) {
+        create_types();
+        create_functions();
+    }
+
+    void create_types();
+    void create_functions();
+
+    llvm::ConstantInt* create_i8(int8_t);
+    llvm::ConstantInt* create_i32(int32_t);
+    llvm::ConstantInt* create_size(size_t);
+
+    llvm::Value* create_pop(llvm::Function*);
+    llvm::Value* create_peek(llvm::Function*, llvm::Value*);
+    void create_push(llvm::Function*, llvm::Value*);
+    void create_popn(llvm::Function*, llvm::Value*);
+    void create_update(llvm::Function*, llvm::Value*);
+    void create_pack(llvm::Function*, llvm::Value*, llvm::Value*);
+    void create_split(llvm::Function*, llvm::Value*);
+    void create_slide(llvm::Function*, llvm::Value*);
+    void create_alloc(llvm::Function*, llvm::Value*);
+    llvm::Value* create_track(llvm::Function*, llvm::Value*);
+
+    void create_unwind(llvm::Function*);
+
+    llvm::Value* unwrap_gmachine_stack_ptr(llvm::Value*);
+
+    llvm::Value* unwrap_num(llvm::Value*);
+    llvm::Value* create_num(llvm::Function*, llvm::Value*);
+
+    llvm::Value* unwrap_data_tag(llvm::Value*);
+
+    llvm::Value* create_global(llvm::Function*, llvm::Value*, llvm::Value*);
+
+    llvm::Value* create_app(llvm::Function*, llvm::Value*, llvm::Value*);
+
+    llvm::Function* create_custom_function(std::string name, int32_t arity);
+};
--- a/code/compiler/12/main.cpp
+++ b/code/compiler/12/main.cpp
@@ -0,0 +1,163 @@
+#include "ast.hpp"
+#include <iostream>
+#include "binop.hpp"
+#include "definition.hpp"
+#include "graph.hpp"
+#include "instruction.hpp"
+#include "llvm_context.hpp"
+#include "parser.hpp"
+#include "error.hpp"
+#include "type.hpp"
+#include "llvm/IR/LegacyPassManager.h"
+#include "llvm/IR/Verifier.h"
+#include "llvm/Support/TargetSelect.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Target/TargetOptions.h"
+#include "llvm/Target/TargetMachine.h"
+
+void yy::parser::error(const std::string& msg) {
+    std::cout << "An error occured: " << msg << std::endl;
+}
+
+extern definition_group global_defs;
+
+void typecheck_program(
+        definition_group& defs,
+        type_mgr& mgr, type_env_ptr& env) {
+    type_ptr int_type = type_ptr(new type_base("Int")); 
+    env->bind_type("Int", int_type);
+    type_ptr int_type_app = type_ptr(new type_app(int_type));
+
+    type_ptr binop_type = type_ptr(new type_arr(
+                int_type_app,
+                type_ptr(new type_arr(int_type_app, int_type_app))));
+    env->bind("+", binop_type, visibility::global);
+    env->bind("-", binop_type, visibility::global);
+    env->bind("*", binop_type, visibility::global);
+    env->bind("/", binop_type, visibility::global);
+
+    std::set<std::string> free;
+    defs.find_free(free);
+    defs.typecheck(mgr, env);
+
+    for(auto& pair : defs.env->names) {
+        std::cout << pair.first << ": ";
+        pair.second.type->print(mgr, std::cout);
+        std::cout << std::endl;
+    }
+}
+
+global_scope translate_program(definition_group& group) {
+    global_scope scope;
+    for(auto& data : group.defs_data) {
+        data.second->into_globals(scope);
+    }
+    for(auto& defn : group.defs_defn) {
+        auto& function = defn.second->into_global(scope);
+        function.body->env->parent->set_mangled_name(defn.first, function.name);
+    }
+    return scope;
+}
+
+void gen_llvm_internal_op(llvm_context& ctx, binop op) {
+    auto new_function = ctx.create_custom_function(op_action(op), 2);
+    std::vector<instruction_ptr> instructions;
+    instructions.push_back(instruction_ptr(new instruction_push(1)));
+    instructions.push_back(instruction_ptr(new instruction_eval()));
+    instructions.push_back(instruction_ptr(new instruction_push(1)));
+    instructions.push_back(instruction_ptr(new instruction_eval()));
+    instructions.push_back(instruction_ptr(new instruction_binop(op)));
+    instructions.push_back(instruction_ptr(new instruction_update(2)));
+    instructions.push_back(instruction_ptr(new instruction_pop(2)));
+    ctx.builder.SetInsertPoint(&new_function->getEntryBlock());
+    for(auto& instruction : instructions) {
+        instruction->gen_llvm(ctx, new_function);
+    }
+    ctx.builder.CreateRetVoid();
+}
+
+void output_llvm(llvm_context& ctx, const std::string& filename) {
+    std::string targetTriple = llvm::sys::getDefaultTargetTriple();
+
+    llvm::InitializeNativeTarget();
+    llvm::InitializeNativeTargetAsmParser();
+    llvm::InitializeNativeTargetAsmPrinter();
+
+    std::string error;
+    const llvm::Target* target =
+        llvm::TargetRegistry::lookupTarget(targetTriple, error);
+    if (!target) {
+        std::cerr << error << std::endl;
+    } else {
+        std::string cpu = "generic";
+        std::string features = "";
+        llvm::TargetOptions options;
+        llvm::TargetMachine* targetMachine =
+            target->createTargetMachine(targetTriple, cpu, features,
+                    options, llvm::Optional<llvm::Reloc::Model>());
+
+        ctx.module.setDataLayout(targetMachine->createDataLayout());
+        ctx.module.setTargetTriple(targetTriple);
+
+        std::error_code ec;
+        llvm::raw_fd_ostream file(filename, ec, llvm::sys::fs::F_None);
+        if (ec) {
+            throw 0;
+        } else {
+            llvm::CodeGenFileType type = llvm::CGFT_ObjectFile;
+            llvm::legacy::PassManager pm;
+            if (targetMachine->addPassesToEmitFile(pm, file, NULL, type)) {
+                throw 0;
+            } else {
+                pm.run(ctx.module);
+                file.close();
+            }
+        }
+    }
+}
+
+void gen_llvm(global_scope& scope) {
+    llvm_context ctx;
+    gen_llvm_internal_op(ctx, PLUS);
+    gen_llvm_internal_op(ctx, MINUS);
+    gen_llvm_internal_op(ctx, TIMES);
+    gen_llvm_internal_op(ctx, DIVIDE);
+
+    scope.generate_llvm(ctx);
+
+    ctx.module.print(llvm::outs(), nullptr);
+    output_llvm(ctx, "program.o");
+}
+
+int main() {
+    yy::parser parser;
+    type_mgr mgr;
+    type_env_ptr env(new type_env);
+
+    parser.parse();
+    for(auto& def_defn : global_defs.defs_defn) {
+        std::cout << def_defn.second->name;
+        for(auto& param : def_defn.second->params) std::cout << " " << param;
+        std::cout << ":" << std::endl;
+
+        def_defn.second->body->print(1, std::cout);
+    }
+    try {
+        typecheck_program(global_defs, mgr, env);
+        global_scope scope = translate_program(global_defs);
+        scope.compile();
+        gen_llvm(scope);
+    } catch(unification_error& err) {
+        std::cout << "failed to unify types: " << std::endl;
+        std::cout << "  (1) \033[34m";
+        err.left->print(mgr, std::cout);
+        std::cout << "\033[0m" << std::endl;
+        std::cout << "  (2) \033[32m";
+        err.right->print(mgr, std::cout);
+        std::cout << "\033[0m" << std::endl;
+    } catch(type_error& err) {
+        std::cout << "failed to type check program: " << err.description << std::endl;
+    }
+}
--- a/code/compiler/12/parsed_type.cpp
+++ b/code/compiler/12/parsed_type.cpp
@@ -0,0 +1,36 @@
+#include "parsed_type.hpp"
+#include "type.hpp"
+#include "type_env.hpp"
+
+type_ptr parsed_type_app::to_type(
+        const std::set<std::string>& vars,
+        const type_env& e) const {
+    auto parent_type = e.lookup_type(name);
+    if(parent_type == nullptr) throw 0;
+    type_base* base_type;
+    if(!(base_type = dynamic_cast<type_base*>(parent_type.get()))) throw 0;
+    if(base_type->arity != arguments.size()) throw 0;
+
+    type_app* new_app = new type_app(std::move(parent_type));
+    type_ptr to_return(new_app);
+    for(auto& arg : arguments) {
+        new_app->arguments.push_back(arg->to_type(vars, e));
+    }
+    return to_return;
+}
+
+type_ptr parsed_type_var::to_type(
+        const std::set<std::string>& vars,
+        const type_env& e) const {
+    if(vars.find(var) == vars.end()) throw 0;
+    return type_ptr(new type_var(var));
+}
+
+
+type_ptr parsed_type_arr::to_type(
+        const std::set<std::string>& vars,
+        const type_env& env) const {
+    auto new_left = left->to_type(vars, env);
+    auto new_right = right->to_type(vars, env);
+    return type_ptr(new type_arr(std::move(new_left), std::move(new_right)));
+}
--- a/code/compiler/12/parsed_type.hpp
+++ b/code/compiler/12/parsed_type.hpp
@@ -0,0 +1,43 @@
+#pragma once
+#include <memory>
+#include <set>
+#include <string>
+#include "type_env.hpp"
+
+struct parsed_type {
+    virtual type_ptr to_type(
+            const std::set<std::string>& vars,
+            const type_env& env) const = 0;
+};
+
+using parsed_type_ptr = std::unique_ptr<parsed_type>;
+
+struct parsed_type_app : parsed_type {
+    std::string name;
+    std::vector<parsed_type_ptr> arguments;
+
+    parsed_type_app(
+            std::string n,
+            std::vector<parsed_type_ptr> as)
+        : name(std::move(n)), arguments(std::move(as)) {}
+
+    type_ptr to_type(const std::set<std::string>& vars, const type_env& env) const;
+};
+
+struct parsed_type_var : parsed_type {
+    std::string var;
+
+    parsed_type_var(std::string v) : var(std::move(v)) {}
+
+    type_ptr to_type(const std::set<std::string>& vars, const type_env& env) const;
+};
+
+struct parsed_type_arr : parsed_type {
+    parsed_type_ptr left;
+    parsed_type_ptr right;
+
+    parsed_type_arr(parsed_type_ptr l, parsed_type_ptr r)
+        : left(std::move(l)), right(std::move(r)) {}
+
+    type_ptr to_type(const std::set<std::string>& vars, const type_env& env) const;
+};
--- a/code/compiler/12/parser.y
+++ b/code/compiler/12/parser.y
@@ -0,0 +1,174 @@
+%{
+#include <string>
+#include <iostream>
+#include <map>
+#include "ast.hpp"
+#include "definition.hpp"
+#include "parser.hpp"
+#include "parsed_type.hpp"
+
+definition_group global_defs;
+
+extern yy::parser::symbol_type yylex();
+
+%}
+
+%token BACKSLASH
+%token PLUS
+%token TIMES
+%token MINUS
+%token DIVIDE
+%token <int> INT
+%token DEFN
+%token DATA
+%token CASE
+%token OF
+%token LET
+%token IN
+%token OCURLY
+%token CCURLY
+%token OPAREN
+%token CPAREN
+%token COMMA
+%token ARROW
+%token EQUAL
+%token <std::string> LID
+%token <std::string> UID
+
+%language "c++"
+%define api.value.type variant
+%define api.token.constructor
+
+%type <std::vector<std::string>> lowercaseParams
+%type <std::vector<branch_ptr>> branches
+%type <std::vector<constructor_ptr>> constructors
+%type <std::vector<parsed_type_ptr>> typeList
+%type <definition_group> definitions
+%type <parsed_type_ptr> type nonArrowType typeListElement
+%type <ast_ptr> aAdd aMul case let lambda app appBase
+%type <definition_data_ptr> data 
+%type <definition_defn_ptr> defn
+%type <branch_ptr> branch
+%type <pattern_ptr> pattern
+%type <constructor_ptr> constructor
+
+%start program
+
+%%
+
+program
+    : definitions { global_defs = std::move($1); global_defs.vis = visibility::global; }
+    ;
+
+definitions
+    : definitions defn { $$ = std::move($1); auto name = $2->name; $$.defs_defn[name] = std::move($2); }
+    | definitions data { $$ = std::move($1); auto name = $2->name; $$.defs_data[name] = std::move($2); }
+    | %empty { $$ = definition_group(); }
+    ;
+
+defn
+    : DEFN LID lowercaseParams EQUAL OCURLY aAdd CCURLY
+        { $$ = definition_defn_ptr(
+            new definition_defn(std::move($2), std::move($3), std::move($6))); }
+    ;
+
+lowercaseParams
+    : %empty { $$ = std::vector<std::string>(); }
+    | lowercaseParams LID { $$ = std::move($1); $$.push_back(std::move($2)); }
+    ;
+
+aAdd
+    : aAdd PLUS aMul { $$ = ast_ptr(new ast_binop(PLUS, std::move($1), std::move($3))); }
+    | aAdd MINUS aMul { $$ = ast_ptr(new ast_binop(MINUS, std::move($1), std::move($3))); }
+    | aMul { $$ = std::move($1); }
+    ;
+
+aMul
+    : aMul TIMES app { $$ = ast_ptr(new ast_binop(TIMES, std::move($1), std::move($3))); }
+    | aMul DIVIDE app { $$ = ast_ptr(new ast_binop(DIVIDE, std::move($1), std::move($3))); }
+    | app { $$ = std::move($1); }
+    ;
+
+app
+    : app appBase { $$ = ast_ptr(new ast_app(std::move($1), std::move($2))); }
+    | appBase { $$ = std::move($1); }
+    ;
+
+appBase
+    : INT { $$ = ast_ptr(new ast_int($1)); }
+    | LID { $$ = ast_ptr(new ast_lid(std::move($1))); }
+    | UID { $$ = ast_ptr(new ast_uid(std::move($1))); }
+    | OPAREN aAdd CPAREN { $$ = std::move($2); }
+    | case { $$ = std::move($1); }
+    | let { $$ = std::move($1); }
+    | lambda { $$ = std::move($1); }
+    ;
+
+let
+    : LET OCURLY definitions CCURLY IN OCURLY aAdd CCURLY
+        { $$ = ast_ptr(new ast_let(std::move($3), std::move($7))); }
+    ;
+
+lambda
+    : BACKSLASH lowercaseParams ARROW OCURLY aAdd CCURLY
+        { $$ = ast_ptr(new ast_lambda(std::move($2), std::move($5))); }
+    ;
+
+case
+    : CASE aAdd OF OCURLY branches CCURLY 
+        { $$ = ast_ptr(new ast_case(std::move($2), std::move($5))); }
+    ;
+
+branches
+    : branches branch { $$ = std::move($1); $$.push_back(std::move($2)); }
+    | branch { $$ = std::vector<branch_ptr>(); $$.push_back(std::move($1));}
+    ;
+
+branch
+    : pattern ARROW OCURLY aAdd CCURLY
+        { $$ = branch_ptr(new branch(std::move($1), std::move($4))); }
+    ;
+
+pattern
+    : LID { $$ = pattern_ptr(new pattern_var(std::move($1))); }
+    | UID lowercaseParams
+        { $$ = pattern_ptr(new pattern_constr(std::move($1), std::move($2))); }
+    ;
+
+data
+    : DATA UID lowercaseParams EQUAL OCURLY constructors CCURLY
+        { $$ = definition_data_ptr(new definition_data(std::move($2), std::move($3), std::move($6))); }
+    ;
+
+constructors
+    : constructors COMMA constructor { $$ = std::move($1); $$.push_back(std::move($3)); }
+    | constructor
+        { $$ = std::vector<constructor_ptr>(); $$.push_back(std::move($1)); }
+    ;
+
+constructor
+    : UID typeList
+        { $$ = constructor_ptr(new constructor(std::move($1), std::move($2))); }
+    ;
+
+type
+    : nonArrowType ARROW type { $$ = parsed_type_ptr(new parsed_type_arr(std::move($1), std::move($3))); }
+    | nonArrowType { $$ = std::move($1); }
+    ;
+
+nonArrowType
+    : UID typeList { $$ = parsed_type_ptr(new parsed_type_app(std::move($1), std::move($2))); }
+    | LID { $$ = parsed_type_ptr(new parsed_type_var(std::move($1))); }
+    | OPAREN type CPAREN { $$ = std::move($2); }
+    ;
+
+typeListElement
+    : OPAREN type CPAREN { $$ = std::move($2); }
+    | UID { $$ = parsed_type_ptr(new parsed_type_app(std::move($1), {})); }
+    | LID { $$ = parsed_type_ptr(new parsed_type_var(std::move($1))); }
+    ;
+
+typeList
+    : %empty { $$ = std::vector<parsed_type_ptr>(); }
+    | typeList typeListElement { $$ = std::move($1); $$.push_back(std::move($2)); }
+    ;
--- a/code/compiler/12/runtime.c
+++ b/code/compiler/12/runtime.c
@@ -0,0 +1,269 @@
+#include <stdint.h>
+#include <assert.h>
+#include <memory.h>
+#include <stdio.h>
+#include "runtime.h"
+
+struct node_base* alloc_node() {
+    struct node_base* new_node = malloc(sizeof(struct node_app));
+    new_node->gc_next = NULL;
+    new_node->gc_reachable = 0;
+    assert(new_node != NULL);
+    return new_node;
+}
+
+struct node_app* alloc_app(struct node_base* l, struct node_base* r) {
+    struct node_app* node = (struct node_app*) alloc_node();
+    node->base.tag = NODE_APP;
+    node->left = l;
+    node->right = r;
+    return node;
+}
+
+struct node_num* alloc_num(int32_t n) {
+    struct node_num* node = (struct node_num*) alloc_node();
+    node->base.tag = NODE_NUM;
+    node->value = n;
+    return node;
+}
+
+struct node_global* alloc_global(void (*f)(struct gmachine*), int32_t a) {
+    struct node_global* node = (struct node_global*) alloc_node();
+    node->base.tag = NODE_GLOBAL;
+    node->arity = a;
+    node->function = f;
+    return node;
+}
+
+struct node_ind* alloc_ind(struct node_base* n) {
+    struct node_ind* node = (struct node_ind*) alloc_node();
+    node->base.tag = NODE_IND;
+    node->next = n;
+    return node;
+}
+
+void free_node_direct(struct node_base* n) {
+    if(n->tag == NODE_DATA) {
+        free(((struct node_data*) n)->array);
+    }
+}
+
+void gc_visit_node(struct node_base* n) {
+    if(n->gc_reachable) return;
+    n->gc_reachable = 1;
+
+    if(n->tag == NODE_APP) {
+        struct node_app* app = (struct node_app*) n;
+        gc_visit_node(app->left);
+        gc_visit_node(app->right);
+    } if(n->tag == NODE_IND) {
+        struct node_ind* ind = (struct node_ind*) n;
+        gc_visit_node(ind->next);
+    } if(n->tag == NODE_DATA) {
+        struct node_data* data = (struct node_data*) n;
+        struct node_base** to_visit = data->array;
+        while(*to_visit) {
+            gc_visit_node(*to_visit);
+            to_visit++;
+        }
+    }
+}
+
+void stack_init(struct stack* s) {
+    s->size = 4;
+    s->count = 0;
+    s->data = malloc(sizeof(*s->data) * s->size);
+    assert(s->data != NULL);
+}
+
+void stack_free(struct stack* s) {
+    free(s->data);
+}
+
+void stack_push(struct stack* s, struct node_base* n) {
+    while(s->count >= s->size) {
+        s->data = realloc(s->data, sizeof(*s->data) * (s->size *= 2));
+        assert(s->data != NULL);
+    }
+    s->data[s->count++] = n;
+}
+
+struct node_base* stack_pop(struct stack* s) {
+    assert(s->count > 0);
+    return s->data[--s->count];
+}
+
+struct node_base* stack_peek(struct stack* s, size_t o) {
+    assert(s->count > o);
+    return s->data[s->count - o - 1];
+}
+
+void stack_popn(struct stack* s, size_t n) {
+    assert(s->count >= n);
+    s->count -= n;
+}
+
+void gmachine_init(struct gmachine* g) {
+    stack_init(&g->stack);
+    g->gc_nodes = NULL;
+    g->gc_node_count = 0;
+    g->gc_node_threshold = 128;
+}
+
+void gmachine_free(struct gmachine* g) {
+    stack_free(&g->stack);
+    struct node_base* to_free = g->gc_nodes;
+    struct node_base* next;
+
+    while(to_free) {
+        next = to_free->gc_next;
+        free_node_direct(to_free);
+        free(to_free);
+        to_free = next;
+    }
+}
+
+void gmachine_slide(struct gmachine* g, size_t n) {
+    assert(g->stack.count > n);
+    g->stack.data[g->stack.count - n - 1] = g->stack.data[g->stack.count - 1];
+    g->stack.count -= n;
+}
+
+void gmachine_update(struct gmachine* g, size_t o) {
+    assert(g->stack.count > o + 1);
+    struct node_ind* ind =
+        (struct node_ind*) g->stack.data[g->stack.count - o - 2];
+    ind->base.tag = NODE_IND;
+    ind->next = g->stack.data[g->stack.count -= 1];
+}
+
+void gmachine_alloc(struct gmachine* g, size_t o) {
+    while(o--) {
+        stack_push(&g->stack,
+                gmachine_track(g, (struct node_base*) alloc_ind(NULL)));
+    }
+}
+
+void gmachine_pack(struct gmachine* g, size_t n, int8_t t) {
+    assert(g->stack.count >= n);
+
+    struct node_base** data = malloc(sizeof(*data) * (n + 1));
+    assert(data != NULL);
+    memcpy(data, &g->stack.data[g->stack.count - n], n * sizeof(*data));
+    data[n] = NULL;
+
+    struct node_data* new_node = (struct node_data*) alloc_node();
+    new_node->array = data;
+    new_node->base.tag = NODE_DATA;
+    new_node->tag = t;
+
+    stack_popn(&g->stack, n);
+    stack_push(&g->stack, gmachine_track(g, (struct node_base*) new_node));
+}
+
+void gmachine_split(struct gmachine* g, size_t n) {
+    struct node_data* node = (struct node_data*) stack_pop(&g->stack);
+    for(size_t i = 0; i < n; i++) {
+        stack_push(&g->stack, node->array[i]);
+    }
+}
+
+struct node_base* gmachine_track(struct gmachine* g, struct node_base* b) {
+    g->gc_node_count++;
+    b->gc_next = g->gc_nodes;
+    g->gc_nodes = b;
+
+    if(g->gc_node_count >= g->gc_node_threshold) {
+        uint64_t nodes_before = g->gc_node_count;
+        gc_visit_node(b);
+        gmachine_gc(g);
+        g->gc_node_threshold = g->gc_node_count * 2;
+    }
+
+    return b;
+}
+
+void gmachine_gc(struct gmachine* g) {
+    for(size_t i = 0; i < g->stack.count; i++) {
+        gc_visit_node(g->stack.data[i]);
+    }
+
+    struct node_base** head_ptr = &g->gc_nodes;
+    while(*head_ptr) {
+        if((*head_ptr)->gc_reachable) {
+            (*head_ptr)->gc_reachable = 0;
+            head_ptr = &(*head_ptr)->gc_next;
+        } else {
+            struct node_base* to_free = *head_ptr;
+            *head_ptr = to_free->gc_next;
+            free_node_direct(to_free);
+            free(to_free);
+            g->gc_node_count--;
+        }
+    }
+}
+
+void unwind(struct gmachine* g) {
+    struct stack* s = &g->stack;
+
+    while(1) {
+        struct node_base* peek = stack_peek(s, 0);
+        if(peek->tag == NODE_APP) {
+            struct node_app* n = (struct node_app*) peek;
+            stack_push(s, n->left);
+        } else if(peek->tag == NODE_GLOBAL) {
+            struct node_global* n = (struct node_global*) peek;
+            assert(s->count > n->arity);
+
+            for(size_t i = 1; i <= n->arity; i++) {
+                s->data[s->count - i]
+                    = ((struct node_app*) s->data[s->count - i - 1])->right;
+            }
+
+            n->function(g);
+        } else if(peek->tag == NODE_IND) {
+            struct node_ind* n = (struct node_ind*) peek;
+            stack_pop(s);
+            stack_push(s, n->next);
+        } else {
+            break;
+        }
+    }
+}
+
+extern void f_main(struct gmachine* s);
+
+void print_node(struct node_base* n) {
+    if(n->tag == NODE_APP) {
+        struct node_app* app = (struct node_app*) n;
+        print_node(app->left);
+        putchar(' ');
+        print_node(app->right);
+    } else if(n->tag == NODE_DATA) {
+        printf("(Packed)");
+    } else if(n->tag == NODE_GLOBAL) {
+        struct node_global* global = (struct node_global*) n;
+        printf("(Global: %p)", global->function);
+    } else if(n->tag == NODE_IND) {
+        print_node(((struct node_ind*) n)->next);
+    } else if(n->tag == NODE_NUM) {
+        struct node_num* num = (struct node_num*) n;
+        printf("%d", num->value);
+    }
+}
+
+int main(int argc, char** argv) {
+    struct gmachine gmachine;
+    struct node_global* first_node = alloc_global(f_main, 0);
+    struct node_base* result;
+
+    gmachine_init(&gmachine);
+    gmachine_track(&gmachine, (struct node_base*) first_node);
+    stack_push(&gmachine.stack, (struct node_base*) first_node);
+    unwind(&gmachine);
+    result = stack_pop(&gmachine.stack);
+    printf("Result: ");
+    print_node(result);
+    putchar('\n');
+    gmachine_free(&gmachine);
+}
--- a/code/compiler/12/runtime.h
+++ b/code/compiler/12/runtime.h
@@ -0,0 +1,84 @@
+#pragma once
+#include <stdlib.h>
+
+struct gmachine;
+
+enum node_tag {
+    NODE_APP,
+    NODE_NUM,
+    NODE_GLOBAL,
+    NODE_IND,
+    NODE_DATA
+};
+
+struct node_base {
+    enum node_tag tag;
+    int8_t gc_reachable;
+    struct node_base* gc_next;
+};
+
+struct node_app {
+    struct node_base base;
+    struct node_base* left;
+    struct node_base* right;
+};
+
+struct node_num {
+    struct node_base base;
+    int32_t value;
+};
+
+struct node_global {
+    struct node_base base;
+    int32_t arity;
+    void (*function)(struct gmachine*);
+};
+
+struct node_ind {
+    struct node_base base;
+    struct node_base* next;
+};
+
+struct node_data {
+    struct node_base base;
+    int8_t tag;
+    struct node_base** array;
+};
+
+struct node_base* alloc_node();
+struct node_app* alloc_app(struct node_base* l, struct node_base* r);
+struct node_num* alloc_num(int32_t n);
+struct node_global* alloc_global(void (*f)(struct gmachine*), int32_t a);
+struct node_ind* alloc_ind(struct node_base* n);
+void free_node_direct(struct node_base*);
+void gc_visit_node(struct node_base*);
+
+struct stack {
+    size_t size;
+    size_t count;
+    struct node_base** data;
+};
+
+void stack_init(struct stack* s);
+void stack_free(struct stack* s);
+void stack_push(struct stack* s, struct node_base* n);
+struct node_base* stack_pop(struct stack* s);
+struct node_base* stack_peek(struct stack* s, size_t o);
+void stack_popn(struct stack* s, size_t n);
+
+struct gmachine {
+    struct stack stack;
+    struct node_base* gc_nodes;
+    int64_t gc_node_count;
+    int64_t gc_node_threshold;
+};
+
+void gmachine_init(struct gmachine* g);
+void gmachine_free(struct gmachine* g);
+void gmachine_slide(struct gmachine* g, size_t n);
+void gmachine_update(struct gmachine* g, size_t o);
+void gmachine_alloc(struct gmachine* g, size_t o);
+void gmachine_pack(struct gmachine* g, size_t n, int8_t t);
+void gmachine_split(struct gmachine* g, size_t n);
+struct node_base* gmachine_track(struct gmachine* g, struct node_base* b);
+void gmachine_gc(struct gmachine* g);
--- a/code/compiler/12/scanner.l
+++ b/code/compiler/12/scanner.l
@@ -0,0 +1,38 @@
+%option noyywrap
+
+%{
+#include <iostream>
+#include "ast.hpp"
+#include "definition.hpp"
+#include "parser.hpp"
+
+#define YY_DECL yy::parser::symbol_type yylex()
+
+%}
+
+%%
+
+[ \n]+ {}
+\\ { return yy::parser::make_BACKSLASH(); }
+\+ { return yy::parser::make_PLUS(); }
+\* { return yy::parser::make_TIMES(); }
+- { return yy::parser::make_MINUS(); }
+\/ { return yy::parser::make_DIVIDE(); }
+[0-9]+ { return yy::parser::make_INT(atoi(yytext)); }
+defn { return yy::parser::make_DEFN(); }
+data { return yy::parser::make_DATA(); }
+case { return yy::parser::make_CASE(); }
+of { return yy::parser::make_OF(); }
+let { return yy::parser::make_LET(); }
+in { return yy::parser::make_IN(); }
+\{ { return yy::parser::make_OCURLY(); }
+\} { return yy::parser::make_CCURLY(); }
+\( { return yy::parser::make_OPAREN(); }
+\) { return yy::parser::make_CPAREN(); }
+,  { return yy::parser::make_COMMA(); }
+-> { return yy::parser::make_ARROW(); }
+= { return yy::parser::make_EQUAL(); }
+[a-z][a-zA-Z]* { return yy::parser::make_LID(std::string(yytext)); }
+[A-Z][a-zA-Z]* { return yy::parser::make_UID(std::string(yytext)); }
+
+%%
--- a/code/compiler/12/test.cpp
+++ b/code/compiler/12/test.cpp
@@ -0,0 +1,23 @@
+#include "graph.hpp"
+
+int main() {
+    function_graph graph;
+    graph.add_edge("f", "g");
+    graph.add_edge("g", "h");
+    graph.add_edge("h", "f");
+
+    graph.add_edge("i", "j");
+    graph.add_edge("j", "i");
+
+    graph.add_edge("j", "f");
+
+    graph.add_edge("x", "f");
+    graph.add_edge("x", "i");
+
+    for(auto& group : graph.compute_order()) {
+        std::cout << "Group: " << std::endl;
+        for(auto& member : group->members) {
+            std::cout << member << std::endl;
+        }
+    }
+}
--- a/code/compiler/12/type.cpp
+++ b/code/compiler/12/type.cpp
@@ -0,0 +1,219 @@
+#include "type.hpp"
+#include <ostream>
+#include <sstream>
+#include <algorithm>
+#include <vector>
+#include "error.hpp"
+
+bool type::is_arrow(const type_mgr& mgr) const { return false; }
+
+void type_scheme::print(const type_mgr& mgr, std::ostream& to) const {
+    if(forall.size() != 0) {
+        to << "forall ";
+        for(auto& var : forall) {
+            to << var << " ";
+        }
+        to << ". ";
+    }
+    monotype->print(mgr, to);
+}
+
+type_ptr type_scheme::instantiate(type_mgr& mgr) const {
+    if(forall.size() == 0) return monotype;
+    std::map<std::string, type_ptr> subst;
+    for(auto& var : forall) {
+        subst[var] = mgr.new_type();
+    }
+    return mgr.substitute(subst, monotype);
+}
+
+void type_var::print(const type_mgr& mgr, std::ostream& to) const {
+    auto it = mgr.types.find(name);
+    if(it != mgr.types.end()) {
+        it->second->print(mgr, to);
+    } else {
+        to << name;
+    }
+}
+
+bool type_var::is_arrow(const type_mgr& mgr) const {
+    auto it = mgr.types.find(name);
+    if(it != mgr.types.end()) {
+        return it->second->is_arrow(mgr);
+    } else {
+        return false;
+    }
+}
+
+void type_base::print(const type_mgr& mgr, std::ostream& to) const {
+    to << name;
+}
+
+void type_arr::print(const type_mgr& mgr, std::ostream& to) const {
+    bool print_parenths = left->is_arrow(mgr);
+    if(print_parenths) to << "(";
+    left->print(mgr, to);
+    if(print_parenths) to << ")";
+    to << " -> ";
+    right->print(mgr, to);
+}
+
+bool type_arr::is_arrow(const type_mgr& mgr) const {
+    return true;
+}
+
+void type_app::print(const type_mgr& mgr, std::ostream& to) const {
+    constructor->print(mgr, to);
+    to << "*";
+    for(auto& arg : arguments) {
+        to << " ";
+        arg->print(mgr, to);
+    }
+}
+
+std::string type_mgr::new_type_name() {
+    int temp = last_id++;
+    std::string str = "";
+
+    while(temp != -1) {
+        str += (char) ('a' + (temp % 26));
+        temp = temp / 26 - 1;
+    }
+
+    std::reverse(str.begin(), str.end());
+    return str;
+}
+
+type_ptr type_mgr::new_type() {
+    return type_ptr(new type_var(new_type_name()));
+}
+
+type_ptr type_mgr::new_arrow_type() {
+    return type_ptr(new type_arr(new_type(), new_type()));
+}
+
+type_ptr type_mgr::resolve(type_ptr t, type_var*& var) const {
+    type_var* cast;
+
+    var = nullptr;
+    while((cast = dynamic_cast<type_var*>(t.get()))) {
+        auto it = types.find(cast->name);
+
+        if(it == types.end()) {
+            var = cast;
+            break;
+        }
+        t = it->second;
+    }
+
+    return t;
+}
+
+void type_mgr::unify(type_ptr l, type_ptr r) {
+    type_var *lvar, *rvar;
+    type_arr *larr, *rarr;
+    type_base *lid, *rid;
+    type_app *lapp, *rapp;
+
+    l = resolve(l, lvar);
+    r = resolve(r, rvar);
+
+    if(lvar) {
+        bind(lvar->name, r);
+        return;
+    } else if(rvar) {
+        bind(rvar->name, l);
+        return;
+    } else if((larr = dynamic_cast<type_arr*>(l.get())) &&
+            (rarr = dynamic_cast<type_arr*>(r.get()))) {
+        unify(larr->left, rarr->left);
+        unify(larr->right, rarr->right);
+        return;
+    } else if((lid = dynamic_cast<type_base*>(l.get())) &&
+            (rid = dynamic_cast<type_base*>(r.get()))) {
+        if(lid->name == rid->name && lid->arity == rid->arity) return;
+    } else if((lapp = dynamic_cast<type_app*>(l.get())) &&
+            (rapp = dynamic_cast<type_app*>(r.get()))) {
+        unify(lapp->constructor, rapp->constructor);
+        auto left_it = lapp->arguments.begin();
+        auto right_it = rapp->arguments.begin();
+        while(left_it != lapp->arguments.end() &&
+                right_it != rapp->arguments.end()) {
+            unify(*left_it, *right_it);
+            left_it++, right_it++;
+        }
+        return;
+    }
+
+    throw unification_error(l, r);
+}
+
+type_ptr type_mgr::substitute(const std::map<std::string, type_ptr>& subst, const type_ptr& t) const {
+    type_ptr temp = t;
+    while(type_var* var = dynamic_cast<type_var*>(temp.get())) {
+        auto subst_it = subst.find(var->name);
+        if(subst_it != subst.end()) return subst_it->second;
+        auto var_it = types.find(var->name);
+        if(var_it == types.end()) return t;
+        temp = var_it->second;
+    }
+
+    if(type_arr* arr = dynamic_cast<type_arr*>(temp.get())) {
+        auto left_result = substitute(subst, arr->left);
+        auto right_result = substitute(subst, arr->right);
+        if(left_result == arr->left && right_result == arr->right) return t;
+        return type_ptr(new type_arr(left_result, right_result));
+    } else if(type_app* app = dynamic_cast<type_app*>(temp.get())) {
+        auto constructor_result = substitute(subst, app->constructor);
+        bool arg_changed = false;
+        std::vector<type_ptr> new_args;
+        for(auto& arg : app->arguments) {
+            auto arg_result = substitute(subst, arg);
+            arg_changed |= arg_result != arg;
+            new_args.push_back(std::move(arg_result));
+        }
+
+        if(constructor_result == app->constructor && !arg_changed) return t;
+        type_app* new_app = new type_app(std::move(constructor_result));
+        std::swap(new_app->arguments, new_args);
+        return type_ptr(new_app);
+    }
+    return t;
+}
+
+void type_mgr::bind(const std::string& s, type_ptr t) {
+    type_var* other = dynamic_cast<type_var*>(t.get());
+    
+    if(other && other->name == s) return;
+    types[s] = t;
+}
+
+void type_mgr::find_free(const type_ptr& t, std::set<std::string>& into) const {
+    type_var* var;
+    type_ptr resolved = resolve(t, var);
+
+    if(var) {
+        into.insert(var->name);
+    } else if(type_arr* arr = dynamic_cast<type_arr*>(resolved.get())) {
+        find_free(arr->left, into);
+        find_free(arr->right, into);
+    } else if(type_app* app = dynamic_cast<type_app*>(resolved.get())) {
+        find_free(app->constructor, into);
+        for(auto& arg : app->arguments) find_free(arg, into);
+    }
+}
+
+void type_mgr::find_free(const type_scheme_ptr& t, std::set<std::string>& into) const {
+    std::set<std::string> monotype_free;
+    type_mgr limited_mgr;
+    for(auto& binding : types) {
+        auto existing_position = std::find(t->forall.begin(), t->forall.end(), binding.first);
+        if(existing_position != t->forall.end()) continue;
+        limited_mgr.types[binding.first] = binding.second;
+    }
+    limited_mgr.find_free(t->monotype, monotype_free);
+    for(auto& not_free : t->forall) {
+        monotype_free.erase(not_free);
+    }
+    into.insert(monotype_free.begin(), monotype_free.end());
+}
--- a/code/compiler/12/type.hpp
+++ b/code/compiler/12/type.hpp
@@ -0,0 +1,99 @@
+#pragma once
+#include <memory>
+#include <map>
+#include <string>
+#include <vector>
+#include <set>
+
+struct type_mgr;
+
+struct type {
+    virtual ~type() = default;
+
+    virtual void print(const type_mgr& mgr, std::ostream& to) const = 0;
+    virtual bool is_arrow(const type_mgr& mgr) const;
+};
+
+using type_ptr = std::shared_ptr<type>;
+
+struct type_scheme {
+    std::vector<std::string> forall;
+    type_ptr monotype;
+
+    type_scheme(type_ptr type) : forall(), monotype(std::move(type)) {}
+
+    void print(const type_mgr& mgr, std::ostream& to) const;
+    type_ptr instantiate(type_mgr& mgr) const;
+};
+
+using type_scheme_ptr = std::shared_ptr<type_scheme>;
+
+struct type_var : public type {
+    std::string name;
+
+    type_var(std::string n)
+        : name(std::move(n)) {}
+
+    void print(const type_mgr& mgr, std::ostream& to) const;
+    bool is_arrow(const type_mgr& mgr) const;
+};
+
+struct type_base : public type {
+    std::string name;
+    int32_t arity;
+
+    type_base(std::string n, int32_t a = 0) 
+        : name(std::move(n)), arity(a) {}
+
+    void print(const type_mgr& mgr, std::ostream& to) const;
+};
+
+struct type_data : public type_base {
+    struct constructor {
+        int tag;
+    };
+
+    std::map<std::string, constructor> constructors;
+
+    type_data(std::string n, int32_t a = 0)
+        : type_base(std::move(n), a) {}
+};
+
+struct type_arr : public type {
+    type_ptr left;
+    type_ptr right;
+
+    type_arr(type_ptr l, type_ptr r)
+        : left(std::move(l)), right(std::move(r)) {}
+
+    void print(const type_mgr& mgr, std::ostream& to) const;
+    bool is_arrow(const type_mgr& mgr) const;
+};
+
+struct type_app : public type {
+    type_ptr constructor;
+    std::vector<type_ptr> arguments;
+
+    type_app(type_ptr c)
+        : constructor(std::move(c)) {}
+
+    void print(const type_mgr& mgr, std::ostream& to) const;
+};
+
+struct type_mgr {
+    int last_id = 0;
+    std::map<std::string, type_ptr> types;
+
+    std::string new_type_name();
+    type_ptr new_type();
+    type_ptr new_arrow_type();
+
+    void unify(type_ptr l, type_ptr r);
+    type_ptr substitute(
+            const std::map<std::string, type_ptr>& subst,
+            const type_ptr& t) const;
+    type_ptr resolve(type_ptr t, type_var*& var) const;
+    void bind(const std::string& s, type_ptr t);
+    void find_free(const type_ptr& t, std::set<std::string>& into) const;
+    void find_free(const type_scheme_ptr& t, std::set<std::string>& into) const;
+};
--- a/code/compiler/12/type_env.cpp
+++ b/code/compiler/12/type_env.cpp
@@ -0,0 +1,85 @@
+#include "type_env.hpp"
+#include "type.hpp"
+
+void type_env::find_free(const type_mgr& mgr, std::set<std::string>& into) const {
+    if(parent != nullptr) parent->find_free(mgr, into);
+    for(auto& binding : names) {
+        mgr.find_free(binding.second.type, into);
+    }
+}
+
+void type_env::find_free_except(const type_mgr& mgr, const group& avoid,
+        std::set<std::string>& into) const {
+    if(parent != nullptr) parent->find_free(mgr, into);
+    for(auto& binding : names) {
+        if(avoid.members.find(binding.first) != avoid.members.end()) continue;
+        mgr.find_free(binding.second.type, into);
+    }
+}
+
+type_scheme_ptr type_env::lookup(const std::string& name) const {
+    auto it = names.find(name);
+    if(it != names.end()) return it->second.type;
+    if(parent) return parent->lookup(name);
+    return nullptr;
+}
+
+bool type_env::is_global(const std::string& name) const {
+    auto it = names.find(name);
+    if(it != names.end()) return it->second.vis == visibility::global;
+    if(parent) return parent->is_global(name);
+    return false;
+}
+
+void type_env::set_mangled_name(const std::string& name, const std::string& mangled) {
+    auto it = names.find(name);
+    if(it != names.end()) it->second.mangled_name = mangled;
+}
+
+const std::string& type_env::get_mangled_name(const std::string& name) const {
+    auto it = names.find(name);
+    if(it != names.end())
+        return (it->second.mangled_name != "") ? it->second.mangled_name : name;
+    if(parent) return parent->get_mangled_name(name);
+    return name;
+}
+
+type_ptr type_env::lookup_type(const std::string& name) const {
+    auto it = type_names.find(name);
+    if(it != type_names.end()) return it->second;
+    if(parent) return parent->lookup_type(name);
+    return nullptr;
+}
+
+void type_env::bind(const std::string& name, type_ptr t, visibility v) {
+    type_scheme_ptr new_scheme(new type_scheme(std::move(t)));
+    names[name] = variable_data(std::move(new_scheme), v, "");
+}
+
+void type_env::bind(const std::string& name, type_scheme_ptr t, visibility v) {
+    names[name] = variable_data(std::move(t), v, "");
+}
+
+void type_env::bind_type(const std::string& type_name, type_ptr t) {
+    if(lookup_type(type_name) != nullptr) throw 0;
+    type_names[type_name] = t;
+}
+
+void type_env::generalize(const std::string& name, const group& grp, type_mgr& mgr) {
+    auto names_it = names.find(name);
+    if(names_it == names.end()) throw 0;
+    if(names_it->second.type->forall.size() > 0) throw 0;
+
+    std::set<std::string> free_in_type;
+    std::set<std::string> free_in_env;
+    mgr.find_free(names_it->second.type->monotype, free_in_type);
+    find_free_except(mgr, grp, free_in_env);
+    for(auto& free : free_in_type) {
+        if(free_in_env.find(free) != free_in_env.end()) continue;
+        names_it->second.type->forall.push_back(free);
+    }
+}
+
+type_env_ptr type_scope(type_env_ptr parent) {
+    return type_env_ptr(new type_env(std::move(parent)));
+}
--- a/code/compiler/12/type_env.hpp
+++ b/code/compiler/12/type_env.hpp
@@ -0,0 +1,49 @@
+#pragma once
+#include <map>
+#include <string>
+#include <set>
+#include "graph.hpp"
+#include "type.hpp"
+
+struct type_env;
+using type_env_ptr = std::shared_ptr<type_env>;
+
+enum class visibility { global,local };
+
+struct type_env {
+    struct variable_data {
+        type_scheme_ptr type;
+        visibility vis;
+        std::string mangled_name;
+
+        variable_data()
+            : variable_data(nullptr, visibility::local, "") {}
+        variable_data(type_scheme_ptr t, visibility v, std::string n)
+            : type(std::move(t)), vis(v), mangled_name(std::move(n)) {}
+    };
+
+    type_env_ptr parent;
+    std::map<std::string, variable_data> names;
+    std::map<std::string, type_ptr> type_names;
+
+    type_env(type_env_ptr p) : parent(std::move(p)) {}
+    type_env() : type_env(nullptr) {}
+
+    void find_free(const type_mgr& mgr, std::set<std::string>& into) const;
+    void find_free_except(const type_mgr& mgr, const group& avoid,
+            std::set<std::string>& into) const;
+    type_scheme_ptr lookup(const std::string& name) const;
+    bool is_global(const std::string& name) const;
+    void set_mangled_name(const std::string& name, const std::string& mangled);
+    const std::string& get_mangled_name(const std::string& name) const;
+    type_ptr lookup_type(const std::string& name) const;
+    void bind(const std::string& name, type_ptr t,
+            visibility v = visibility::local);
+    void bind(const std::string& name, type_scheme_ptr t,
+            visibility v = visibility::local);
+    void bind_type(const std::string& type_name, type_ptr t);
+    void generalize(const std::string& name, const group& grp, type_mgr& mgr);
+};
+
+
+type_env_ptr type_scope(type_env_ptr parent);
--- a/code/compiler/test.sh
+++ b/code/compiler/test.sh
@@ -1,4 +1,4 @@
-cd 10
+cd 11
 mkdir -p build && cd build
 cmake ..
 make -j8
--- a/config.toml
+++ b/config.toml
@@ -4,3 +4,10 @@ title = "Daniel's Blog"
 theme = "vanilla"
 pygmentsCodeFences = true
 pygmentsStyle = "github"
+summaryLength = 20
+
+[markup]
+  [markup.tableOfContents]
+    endLevel = 4
+    ordered = false
+    startLevel = 3
--- a/content/_index.md
+++ b/content/_index.md
@@ -1,5 +1,6 @@
 ---
 title: Daniel's Blog
+description: Daniel Fedorin's personal blog, covering topics such as functional programming, compiler development, and more!
 ---
 ## Hello!
 Welcome to my blog. Here, I write about various subjects, including (but not limited to)
--- a/content/blog/00_compiler_intro.md
+++ b/content/blog/00_compiler_intro.md
@@ -2,6 +2,7 @@
 title: Compiling a Functional Language Using C++, Part 0 - Intro
 date: 2019-08-03T01:02:30-07:00
 tags: ["C and C++", "Functional Languages", "Compilers"]
+description: "In this first post of a larger series, we embark on a journey of developing a compiler for a lazily evaluated functional language."
 ---
 During my last academic term, I was enrolled in a compilers course.
 We had a final project - develop a compiler for a basic Python subset,
@@ -143,3 +144,5 @@ Here are the posts that I've written so far for this series:
 * [Garbage Collection]({{< relref "09_compiler_garbage_collection.md" >}})
 * [Polymorphism]({{< relref "10_compiler_polymorphism.md" >}})
 * [Polymorphic Data Types]({{< relref "11_compiler_polymorphic_data_types.md" >}})
+* [Let/In and Lambdas]({{< relref "12_compiler_let_in_lambda/index.md" >}})
+
--- a/content/blog/01_compiler_tokenizing.md
+++ b/content/blog/01_compiler_tokenizing.md
@@ -2,6 +2,7 @@
 title: Compiling a Functional Language Using C++, Part 1 - Tokenizing
 date: 2019-08-03T01:02:30-07:00
 tags: ["C and C++", "Functional Languages", "Compilers"]
+description: "In this post, we tackle the first component of our compiler: tokenizing."
 ---
 It makes sense to build a compiler bit by bit, following the stages we outlined in
 the first post of the series. This is because these stages are essentially a pipeline,
--- a/content/blog/02_compiler_parsing.md
+++ b/content/blog/02_compiler_parsing.md
@@ -2,6 +2,7 @@
 title: Compiling a Functional Language Using C++, Part 2 - Parsing
 date: 2019-08-03T01:02:30-07:00
 tags: ["C and C++", "Functional Languages", "Compilers"]
+description: "In this post, we combine our compiler's tokenizer with a parser, allowing us to extract structure from input source code."
 ---
 In the previous post, we covered tokenizing. We learned how to convert an input string into logical segments, and even wrote up a tokenizer to do it according to the rules of our language. Now, it's time to make sense of the tokens, and parse our language.

--- a/content/blog/03_compiler_typechecking.md
+++ b/content/blog/03_compiler_typechecking.md
@@ -2,6 +2,7 @@
 title: Compiling a Functional Language Using C++, Part 3 - Type Checking
 date: 2019-08-06T14:26:38-07:00
 tags: ["C and C++", "Functional Languages", "Compilers"]
+description: "In this post, we allow our compiler to throw away invalid programs, detected using a monomorphic typechecking algorithm."
 ---
 I think tokenizing and parsing are boring. The thing is, looking at syntax
 is a pretty shallow measure of how interesting a language is. It's like
--- a/content/blog/04_compiler_improvements.md
+++ b/content/blog/04_compiler_improvements.md
@@ -2,6 +2,7 @@
 title: Compiling a Functional Language Using C++, Part 4 - Small Improvements
 date: 2019-08-06T14:26:38-07:00
 tags: ["C and C++", "Functional Languages", "Compilers"]
+description: "In this post, we take a little break from pushing our compiler forward to make some improvements to the code we've written so far."
 ---
 We've done quite a big push in the previous post. We defined
 type rules for our language, implemented unification,
--- a/content/blog/05_compiler_execution.md
+++ b/content/blog/05_compiler_execution.md
@@ -2,6 +2,7 @@
 title: Compiling a Functional Language Using C++, Part 5 - Execution
 date: 2019-08-06T14:26:38-07:00
 tags: ["C and C++", "Functional Languages", "Compilers"]
+description: "In this post, we define the rules for a G-machine, the abstract machine that we will target with our compiler."
 ---
 {{< gmachine_css >}}
 We now have trees representing valid programs in our language,
--- a/content/blog/06_compiler_compilation.md
+++ b/content/blog/06_compiler_compilation.md
@@ -2,6 +2,7 @@
 title: Compiling a Functional Language Using C++, Part 6 - Compilation
 date: 2019-08-06T14:26:38-07:00
 tags: ["C and C++", "Functional Languages", "Compilers"]
+description: "In this post, we enable our compiler to convert programs written in our functional language to G-machine instructions."
 ---
 In the previous post, we defined a machine for graph reduction,
 called a G-machine. However, this machine is still not particularly
--- a/content/blog/07_compiler_runtime.md
+++ b/content/blog/07_compiler_runtime.md
@@ -2,6 +2,7 @@
 title: Compiling a Functional Language Using C++, Part 7 - Runtime
 date: 2019-08-06T14:26:38-07:00
 tags: ["C and C++", "Functional Languages", "Compilers"]
+description: "In this post, we implement the supporting code that will be shared between all executables our compiler will create."
 ---
 Wikipedia has the following definition for a __runtime__:

--- a/content/blog/08_compiler_llvm.md
+++ b/content/blog/08_compiler_llvm.md
@@ -2,6 +2,7 @@
 title: Compiling a Functional Language Using C++, Part 8 - LLVM
 date: 2019-10-30T22:16:22-07:00
 tags: ["C and C++", "Functional Languages", "Compilers"]
+description: "In this post, we enable our compiler to convert G-machine instructions to LLVM IR, which finally allows us to generate working executables."
 ---

 We don't want a compiler that can only generate code for a single
--- a/content/blog/09_compiler_garbage_collection.md
+++ b/content/blog/09_compiler_garbage_collection.md
@@ -2,6 +2,7 @@
 title: Compiling a Functional Language Using C++, Part 9 - Garbage Collection
 date: 2020-02-10T19:22:41-08:00
 tags: ["C and C++", "Functional Languages", "Compilers"]
+description: "In this post, we implement a garbage collector that frees memory no longer used by the executables our compiler creates."
 ---

 > "When will you learn? When will you learn that __your actions have consequences?__"
--- a/content/blog/10_compiler_polymorphism.md
+++ b/content/blog/10_compiler_polymorphism.md
@@ -2,6 +2,7 @@
 title: Compiling a Functional Language Using C++, Part 10 - Polymorphism
 date: 2020-03-25T17:14:20-07:00
 tags: ["C and C++", "Functional Languages", "Compilers"]
+description: "In this post, we extend our compiler's typechecking algorithm to implement the Hindley-Milner type system, allowing for polymorphic functions."
 ---

 [In part 8]({{< relref "08_compiler_llvm.md" >}}), we wrote some pretty interesting programs in our little language.
--- a/content/blog/11_compiler_polymorphic_data_types.md
+++ b/content/blog/11_compiler_polymorphic_data_types.md
@@ -2,6 +2,7 @@
 title: Compiling a Functional Language Using C++, Part 11 - Polymorphic Data Types
 date: 2020-04-14T19:05:42-07:00
 tags: ["C and C++", "Functional Languages", "Compilers"]
+description: "In this post, we enable our compiler to understand polymorphic data types."
 ---
 [In part 10]({{< relref "10_compiler_polymorphism.md" >}}), we managed to get our
 compiler to accept functions that were polymorphically typed. However, a piece
@@ -395,4 +396,5 @@ Result: 4

 This looks good! We have added support for polymorphic data types to our compiler.
 We are now free to move on to `let/in` expressions, __lambda functions__, and __Input/Output__,
-as promised! I'll see you then!
+as promised, starting with [part 12]({{< relref "12_compiler_let_in_lambda/index.md" >}}) - `let/in`
+and lambdas!
--- a/content/blog/12_compiler_let_in_lambda/index.md
+++ b/content/blog/12_compiler_let_in_lambda/index.md
--- a/content/blog/crystal_nix_revisited.md
+++ b/content/blog/crystal_nix_revisited.md
@@ -0,0 +1,112 @@
+---
+title: Building a Crystal Project with Nix, Revisited
+date: 2020-04-26T18:37:22-07:00
+tags: ["Crystal", "Nix"]
+---
+
+As I've described in my [previous post]({{< relref "crystal_nix.md" >}}), the process for compiling a Crystal project with Nix is a fairly straightforward one. As is standard within the Nix ecosystem, the project's dependencies, as specified by the source language's build system (shards, in Crystal's case), are converted into a Nix expression (`shards.nix`). These dependencies are then used in a derivation, which, in Crystal's case, can take advantage of `buildCrystalPackage` to reduce boilerplate build scripts. All is well.
+
+Things start to fall apart a little bit when the Crystal project being built is more complex. The predefined infrastructure (like `buildCrystalPackage`)
+{{< sidenote "right" "versatility-note" "is not written with versatility in mind," >}}
+This is not a bad thing at all; it's much better to get something working for the practical case, rather than concoct an overcomplicated solution that covers all theoretically possible cases.
+{{< /sidenote >}} though it seems to work exceptionally in the common case. Additionally, I discovered that the compiler itself has some quirks, and have killed a few hours of my time trying to figure out some unexpected behaviors.
+
+This post will cover the extra, more obscure steps I had to take to build an HTTPS-enabled Crystal project.
+
+### First Problem: Git-Based Dependencies
+A lot of my projects use Crystal libraries that are not hosted on GitHub at all; I use a private Git server, and most of my non-public code resides on it. The Crystal people within Nix don't seem to like this: let's look at the code for `crystal2nix.cr` file in the [nixpkgs repository](https://github.com/NixOS/nixpkgs/blob/1ffdf01777360f548cc7c10ef5b168cbe78fd183/pkgs/development/compilers/crystal/crystal2nix.cr). In particular, consider lines 18 and 19:
+```Crystal {linenos=table,linenostart=18}
+yaml.shards.each do |key, value|
+  owner, repo = value["github"].split("/")
+```
+Ouch! If you as much as mention a non-GitHub repository in your `shards.lock` file, you will experience  a good old uncaught exception. Things don't end there, either. Nix provides a convenient `fetchFromGitHub` function, which only requires a repository name and its enclosing namespace (user or group). `crystal2nix` uses this, by generating a file with that information:
+```Crystal {linenos=table,linenostart=34}
+file.puts %(  #{key} = {)
+file.puts %(    owner = "#{owner}";)
+file.puts %(    repo = "#{repo}";)
+file.puts %(    rev = "#{rev}";)
+file.puts %(    sha256 = "#{sha256}";)
+file.puts %(  };)
+```
+And, of course, `build-package.nix` (of which [this is the version at the time of writing](https://github.com/NixOS/nixpkgs/blob/912eb6b120eba15237ff053eafc4b5d90577685b/pkgs/development/compilers/crystal/build-package.nix)) uses this to declare dependencies:
+```Nix {linenos=table,linenostart=26}
+crystalLib = linkFarm "crystal-lib" (lib.mapAttrsToList (name: value: {
+  inherit name;
+  path = fetchFromGitHub value;
+}) (import shardsFile));
+```
+This effectively creates a folder of dependencies cloned from GitHub, which is then placed into `lib` as if `shards` was run:
+```Nix {linenos=table,linenostart=37}
+configurePhase = args.configurePhase or lib.concatStringsSep "\n" ([
+ "runHook preConfigure"
+] ++ lib.optional (lockFile != null)   "ln -s ${lockFile} ./shard.lock"
+  ++ lib.optional (shardsFile != null) "ln -s ${crystalLib} lib"
+  ++ [ "runHook postConfigure "]);
+```
+Sleek, except that there's no place in this flow for dependencies based _only_ on Git! `crystalLib` is declared locally in a `let/in` expression, and we don't have access to it; neither can we call `linkFarm` again, since this results in a derivation, which, with different inputs, will be created at a different path. To work around this, I made my own Nix package, called `customCrystal`, and had it pass several modifications to `buildCrystalPackage`:
+```Nix
+{ stdenv, lib, linkFarm, fetchgit, fetchFromGitHub }:
+
+{ crystal,
+  gitShardsFile ? null,
+  lockFile ? null,
+  shardsFile ? null, ...}@args:
+
+let
+    buildArgs = builtins.removeAttrs args [ "crystal" ];
+    githubLinks = lib.mapAttrsToList (name: value: {
+        inherit name;
+        path = fetchFromGitHub value;
+    }) (import shardsFile);
+    gitLinks = lib.mapAttrsToList (name: value: {
+        inherit name;
+	path = fetchgit { inherit (value) url rev sha256; };
+    }) (import gitShardsFile);
+    crystalLib = linkFarm "crystal-lib" (githubLinks ++ gitLinks);
+    configurePhase = args.configurePhase or lib.concatStringsSep "\n" ([
+        "runHook preConfigure"
+    ] ++ lib.optional (lockFile != null)   "ln -s ${lockFile} ./shard.lock"
+        ++ lib.optional (shardsFile != null) "ln -s ${crystalLib} lib"
+	++ [ "runHook postConfigure "]);
+in
+    crystal.buildCrystalPackage (buildArgs // { inherit configurePhase; })
+```
+This does pretty much the equivalent of what `buildCrystalPackage` does (indeed, it does the heavy lifting). However, this snippet also retrieves Git repositories from the `gitShardsFile`, and creates the `lib` folder using both Git and GitHub dependencies. I didn't bother writing a `crystal2nix` equivalent for this, since I only had a couple of dependencies. I invoked my new function like `buildCrystalPackage`, with the addition of passing in the Crystal package, and that problem was solved.
+
+### Second Problem: OpenSSL
+The package I was trying to build used Crystal's built-in HTTP client, which, in turn, required OpenSSL. This, I thought, would be rather straightforward: add `openssl` to my package's `buildInputs`, and be done with it. It was not as simple, though, and I was greeted with a wall of errors like this one:
+
+```
+/nix/store/sq2b0dqlq243mqn4ql5h36xmpplyy20k-binutils-2.31.1/bin/ld: _main.o: in function `__crystal_main':
+main_module:(.text+0x6f0): undefined reference to `SSL_library_init'
+/nix/store/sq2b0dqlq243mqn4ql5h36xmpplyy20k-binutils-2.31.1/bin/ld: main_module:(.text+0x6f5): undefined reference to `SSL_load_error_strings'
+/nix/store/sq2b0dqlq243mqn4ql5h36xmpplyy20k-binutils-2.31.1/bin/ld: main_module:(.text+0x6fa): undefined reference to `OPENSSL_add_all_algorithms_noconf'
+/nix/store/sq2b0dqlq243mqn4ql5h36xmpplyy20k-binutils-2.31.1/bin/ld: main_module:(.text+0x6ff): undefined reference to `ERR_load_crypto_strings'
+/nix/store/sq2b0dqlq243mqn4ql5h36xmpplyy20k-binutils-2.31.1/bin/ld: _main.o: in function `*HTTP::Client::new<String, (Int32 | Nil), Bool>:HTTP::Client':
+```
+
+Some snooping led me to discover that these symbols were part of OpenSSL 1.0.2, support for which ended in 2019. OpenSSL 1.1.0 has these symbols deprecated, and from what I can tell, they might be missing from the `.so` file altogether. I tried changing the package to specifically accept OpenSSL 1.0.2, but that didn't work, either: for some reason, the Crystal kept running the `gcc` command with `-L...openssl-1.1.0`. It also seemed like the compiler itself was built against the most recent version of OpenSSL, so what's the issue? I discovered this is a problem in the compiler itself. Consider the following line from Crystal's `openssl/lib_ssl.cr` [source file](https://github.com/crystal-lang/crystal/blob/0.34.0/src/openssl/lib_ssl.cr):
+
+```Crystal {linenos=table,linenostart=8}
+ {% ssl_version = `hash pkg-config 2> /dev/null && pkg-config --silence-errors --modversion libssl || printf %s 0.0.0`.split.last.gsub(/[^0-9.]/, "") %}
+```
+
+Excuse me? If `pkg-config` is not found (which, in Nix, it won't be by default), Crystal assumes that it's using the _least_ up-to-date version of OpenSSL,
+{{< sidenote "right" "version-note" "indicated by version code 0.0.0." >}}
+The Crystal compiler compares version numbers based on semantic versioning, it seems, and 0.0.0 will always compare to be less than any other version of OpenSSL. Thus, code 0.0.0 indicates that Crystal should assume it's dealing with an extremely old version of OpenSSL.
+{{< /sidenote >}} This matters, because later on in the file, we get this beauty:
+
+```Crystal {linenos=table,linenostart=215}
+{% if compare_versions(OPENSSL_VERSION, "1.1.0") >= 0 %}
+  fun tls_method = TLS_method : SSLMethod
+{% else %}
+  fun ssl_library_init = SSL_library_init
+  fun ssl_load_error_strings = SSL_load_error_strings
+  fun sslv23_method = SSLv23_method : SSLMethod
+{% end %}
+```
+
+That would be where the linker errors are coming from. Adding `pkg-config`to `buildInputs` along with `openssl` fixes the issue, and my package builds without problems.
+
+### Conclusion
+Crystal is a rather obscure language, and Nix is a rather obscure build system. I'm grateful that the infrastructure I'm using exists, and that using it is as streamlined as it is. There is, however, always room for improvement. If I have time, I will be opening pull requests for the `crystal2nix` tool on GitHub (to allow Git-based repositories), and perhaps on the Crystal compiler as well (to try figure out what to do about `pkg-config`). If someone else wants to do it themselves, I'd be happy to hear how it goes! Otherwise, I hope you found this post useful.
--- a/content/blog/haskell_lazy_evaluation.md
+++ b/content/blog/haskell_lazy_evaluation.md
@@ -0,0 +1,95 @@
+---
+title: "Clairvoyance for Good: Using Lazy Evaluation in Haskell"
+date: 2020-05-03T20:05:29-07:00
+tags: ["Haskell"]
+draft: true
+---
+
+While tackling a project for work, I ran across a rather unpleasant problem.
+I don't think it's valuable to go into the specifics here (it's rather
+large and convoluted); however, the outcome of this experience led me to
+discover a very interesting technique for lazy functional languages,
+and I want to share what I learned.
+
+### Time Traveling
+Some time ago, I read [this post](https://kcsongor.github.io/time-travel-in-haskell-for-dummies/) by Csongor Kiss about time traveling in Haskell. It's
+really cool, and makes a lot of sense if you have wrapped your head around
+lazy evaluation. I'm going to present my take on it here, but please check out
+Csongor's original post if you are interested.
+
+Say that you have a list of integers, like `[3,2,6]`. Next, suppose that
+you want to find the maximum value in the list. You can implement such
+behavior quite simply with pattern matching:
+
+```Haskell
+myMax :: [Int] -> Int
+myMax [] = error "Being total sucks"
+myMax (x:xs) = max x $ myMax xs
+```
+
+You could even get fancy with a `fold`:
+
+```Haskell
+myMax :: [Int] -> Int
+myMax = foldr1 max
+```
+
+All is well, and this is rather elementary Haskell. But now let's look at
+something that Csongor calls the `repMax` problem:
+
+> Imagine you had a list, and you wanted to replace all the elements of the
+> list with the largest element, by only passing the list once.
+
+How can we possibly do this in one pass? First, we need to find the maximum
+element, and only then can we have something to replace the other numbers
+with! It turns out, though, that we can just expect to have the future
+value, and all will be well. Csongor provides the following example:
+
+```Haskell {linenos=table}
+repMax :: [Int] -> Int -> (Int, [Int])
+repMax [] rep = (rep, [])
+repMax [x] rep = (x, [rep])
+repMax (l : ls) rep = (m', rep : ls')
+  where (m, ls') = repMax ls rep
+        m' = max m l
+
+doRepMax :: [Int] -> [Int]
+doRepMax xs = xs'
+  where (largest, xs') = repMax xs largest
+```
+
+In the above snippet, `repMax` expects to receive the maximum value of
+its input list. At the same time, it also computes that maximum value,
+returning it and the newly created list. `doRepMax` is where the magic happens:
+the `where` clauses receives the maximum number from `repMax`, while at the
+same time using that maximum number to call `repMax`!
+
+This works because Haskell's evaluation model is, effectively,
+[lazy graph reduction](https://en.wikipedia.org/wiki/Graph_reduction). That is,
+you can think of Haskell as manipulating your code as
+{{< sidenote "right" "tree-note" "a syntax tree," >}}
+Why is it called graph reduction, you may be wondering, if the runtime is
+manipulating syntax trees? To save on work, if a program refers to the
+same value twice, Haskell has both of those references point to the
+exact same graph. This violates the tree's property of having only one path
+from the root to any node, and makes our program a graph. Graphs that
+refer to themselves also violate the properties of a tree.
+{{< /sidenote >}} performing
+substitutions and simplifications as necessary until it reaches a final answer.
+What the lazy part means is that parts of the syntax tree that are not yet
+needed to compute the final answer can exist, unsimplied, in the tree. This is
+what allows us to write the code above: the graph of `repMax xs largest`
+effectively refers to itself. While traversing the list, it places references
+to itself in place of each of the elements, and thanks to laziness, these
+references are not evaluated.
+
+Let's try a more complicated example. How about instead of creating a new list,
+we return a `Map` containing the number of times each number occured, but only
+when those numbers were a factor of the maximum numbers. Our expected output
+will be:
+
+```
+>>> countMaxFactors [1,3,3,9]
+
+fromList [(1, 1), (3, 2), (9, 1)]
+```
--- a/content/blog/starbound.md
+++ b/content/blog/starbound.md
@@ -12,7 +12,7 @@ __py-starbound__, nicely enough, actually has a file named `FORMATS.md`. This fi
 > This section will contain information on how to retrieve a value from a BTreeDB5 database.

 Not very helpful. Before I go into what I managed to determine from the code, we may first take a look at one thing that we already know about the world format - it is a [B-Tree](https://en.wikipedia.org/wiki/B-tree).
-## Binary Search Trees
+### Binary Search Trees
 The B-Tree is a generalization of a Binary Search Tree, or BST for short. Binary Search trees (and B-Trees in general) operate on data that can be ordered consistently, the simplest example being numbers. For instance, as an example, I'll be using a BST that holds integers. A BST is made up of nodes, objects that actually hold the pieces of data that the tree itself organizes.

 In a BST, the nodes are organized in a simple way. Each node can have up to two _children_ (sub-nodes), and each of those can have up to two children, etc. The children are generally classified as _right_ and _left_. Conventionally, left children always have a value that is below (or comes before) the value of the node whose child they are (their _parent_), and right children have a bigger value.
@@ -45,7 +45,7 @@ __Although the average efficiency of a Binary Search Tree is \\(O(\log n)\\), me

 This isn't good enough, and many clever algorithms have been invented to speed up the lookup of the tree by making sure that it remains _balanced_ - that is, it _isn't_ arranged like a simple list. Some of these algorithms include [Red-Black Trees](https://en.wikipedia.org/wiki/Red%E2%80%93black_tree), [AVL Trees](https://en.wikipedia.org/wiki/AVL_tree), and, of course, B-Trees.

-## B-Trees
+### B-Trees
 B-Trees are a generalization of Binary Search Trees. That means that every Binary Search Tree is a B-Tree, but not all B-Trees are BSTs. The key difference lies in the fact that B-Trees' nodes aren't limited to having only two child nodes, and can also have more than one value.

 Each B-Tree node is a sorted array of values. That is, instead of a single number like the BST that we've looked at, it has multiple, and these numbers _must_ be sorted. Below are some examples of B-Tree nodes:
@@ -64,7 +64,7 @@ This is solved using another property of B-Trees - the number of children of a n

 If we were looking for the number 15, we'd look between the 10 and the 20, examining the 2nd node, and if we were looking for 45 we'd look past the 30, at the 4th node.

-## Starbound B-Trees and BTreeDB5
+### Starbound B-Trees and BTreeDB5
 The BTreeDB5 data structure uses something other than integers for its keys - it uses sequences of bytes. These bytes are compared in a very similar fashion to integers. The game first looks at the first number in the sequence of bytes (like the largest digit in an integer), and if that's the same, moves on to the next one. Also, Starbound B-Trees not only have the values, or _keys_, that they use to find data, but the data itself.

 The "nodes" in the BTreeDB are called "blocks" and are one of three types - "index", "leaf", and "free" nodes. "Index" nodes are like the `(10, 20, 30)` node in the above example - they point to other nodes, but actually store no data themselves. The "leaf" nodes actually contain the data, and, if that data is longer than the maximum block size, "leaf" nodes contain the index of the next leaf node where the user might continue to read the data. The "free" nodes are simply free data, empty and ready for Starbound to fill them with something useful.
--- a/themes/vanilla/assets/scss/margin.scss
+++ b/themes/vanilla/assets/scss/margin.scss
@@ -0,0 +1,47 @@
+@import "variables.scss";
+@import "mixins.scss";
+
+$margin-width: 30rem;
+$margin-inner-offset: 0.5rem;
+$margin-outer-offset: 1rem;
+
+@mixin below-two-margins {
+    @media screen and
+        (max-width: $container-width-threshold +
+            2 * ($margin-width + $margin-inner-offset + $margin-outer-offset)) {
+        @content;
+    }
+}
+
+@mixin below-one-margin {
+    @media screen and
+        (max-width: $container-width-threshold +
+            ($margin-width + $margin-inner-offset + $margin-outer-offset)) {
+        @content;
+    }
+}
+
+@mixin margin-content {
+    display: block;
+    position: absolute;
+    width: $margin-width;
+    box-sizing: border-box;
+}
+
+@mixin margin-content-left {
+    left: 0;
+    margin-left: -($margin-width + $container-min-padding + $margin-inner-offset);
+
+    @include below-two-margins {
+        display: none;
+    }
+}
+
+@mixin margin-content-right {
+    right: 0;
+    margin-right: -($margin-width + $container-min-padding + $margin-inner-offset);
+
+    @include below-one-margin {
+        display: none;
+    }
+}
--- a/themes/vanilla/assets/scss/mixins.scss
+++ b/themes/vanilla/assets/scss/mixins.scss
@@ -6,7 +6,7 @@
 }

@mixin below-container-width {
-    @media screen and (max-width: $container-width){
+    @media screen and (max-width: $container-width-threshold){
        @content;
    }
 }
--- a/themes/vanilla/assets/scss/sidenotes.scss
+++ b/themes/vanilla/assets/scss/sidenotes.scss
@@ -1,28 +1,10 @@
@import "variables.scss";
@import "mixins.scss";
+@import "margin.scss";

-$sidenote-accommodate-shrink: 10rem;
-$sidenote-width: 30rem;
-$sidenote-offset: 1.5rem;
 $sidenote-padding: 1rem;
 $sidenote-highlight-border-width: .2rem;

-@mixin below-two-sidenotes {
-    @media screen and
-        (max-width: $container-width +
-            2 * ($sidenote-width + 2 * $sidenote-offset)) {
-        @content;
-    }
-}
-
-@mixin below-one-sidenote {
-    @media screen and
-        (max-width: $container-width +
-            ($sidenote-width + 3 * $sidenote-offset)) {
-        @content;
-    }
-}
-
 .sidenote {
    &:hover {
        .sidenote-label {
@@ -40,7 +22,7 @@ $sidenote-highlight-border-width: .2rem;
 }

 .sidenote-label {
-    border-bottom: .2rem solid $primary-color;
+    border-bottom: .2rem dashed $primary-color;
 }

 .sidenote-checkbox {
@@ -48,25 +30,19 @@ $sidenote-highlight-border-width: .2rem;
 }

 .sidenote-content {
-    display: block;
-    position: absolute;
-    width: $sidenote-width;
+    @include margin-content;
+    @include bordered-block;
    margin-top: -1.5rem;
+    padding: $sidenote-padding;
+    text-align: left;

    &.sidenote-right {
-        right: 0;
-        margin-right: -($sidenote-width + $sidenote-offset);
+        @include margin-content-right;
    }

    &.sidenote-left {
-        left: 0;
-        margin-left: -($sidenote-width + $sidenote-offset);
+        @include margin-content-left;
    }
-
-    @include bordered-block;
-    padding: $sidenote-padding;
-    box-sizing: border-box;
-    text-align: left;
 }

 .sidenote-delimiter {
@@ -78,36 +54,22 @@ $sidenote-highlight-border-width: .2rem;
    margin-top: 1rem;
    margin-bottom: 1rem;
    width: 100%;
-    display: none;

    .sidenote-checkbox:checked ~ & {
        display: block;
    }
 }

-@include below-two-sidenotes {
+@include below-two-margins {
    .sidenote-content.sidenote-left {
        @include hidden-sidenote;
        margin-left: 0rem;
    }
-
-    .container {
-        left: -$sidenote-width/2
-    }
 }

-@include below-one-sidenote {
-    .post-content {
-        max-width: 100%;
-    }
-
+@include below-one-margin {
    .sidenote-content.sidenote-right {
        @include hidden-sidenote;
        margin-right: 0rem;
    }
-
-    .container {
-        position: initial;
-    }
 }
-
--- a/themes/vanilla/assets/scss/style.scss
+++ b/themes/vanilla/assets/scss/style.scss
@@ -1,5 +1,7 @@
@import "variables.scss";
@import "mixins.scss";
+@import "margin.scss";
+@import "toc.scss";

 body {
  font-family: $font-body;
@@ -7,6 +9,10 @@ body {
  line-height: 1.5;
  margin-bottom: 1rem;
  text-align: justify;
+
+  @include below-container-width {
+    text-align: left;
+  }
 }

 h1, h2, h3, h4, h5, h6 {
@@ -14,10 +20,10 @@ h1, h2, h3, h4, h5, h6 {
  margin-top: .5rem;
  font-family: $font-heading;
  font-weight: normal;
-  text-align: left;
+  text-align: center;

  a {
-    color: black;
+    border-bottom: none;

    &:hover {
      color: $primary-color;
@@ -34,7 +40,20 @@ pre code {
    display: block;
    padding: 0.5rem;
    overflow-x: auto;
-    background-color: $code-color;
+    border: $code-border;
+}
+
+div.highlight table {
+    border: $code-border !important;
+    border-radius: 0px;
+
+    pre {
+        margin: 0;
+    }
+
+    code {
+        border: none;
+    }
 }

 .container {
@@ -45,7 +64,17 @@ pre code {
  box-sizing: border-box;

  @include below-container-width {
-      padding: 0rem 1rem 0rem 1rem;
+      padding: 0 $container-min-padding 0 $container-min-padding;
+      margin: 0;
+      max-width: $container-width + 2 * $container-min-padding;
+  }
+
+  @include below-two-margins {
+      left: -($margin-width + $margin-inner-offset + $margin-outer-offset)/2;
+  }
+
+  @include below-one-margin {
+      left: 0;
  }
 }

@@ -54,8 +83,7 @@ pre code {
  background-color: $primary-color;
  border: none;
  color: white;
-  transition: color 0.25s;
-  transition: background-color 0.25s;
+  transition: color 0.25s, background-color 0.25s;
  text-align: left;

  &:focus {
@@ -69,28 +97,28 @@ pre code {
 }

 nav {
-  background-color: $primary-color;
  width: 100%;
-  margin: 1rem 0rem 1rem 0rem;
-}
+  margin: 0rem 0rem 1rem 0rem;

-nav a {
-  padding: .75em;
-  text-decoration: none;
-  color: white;
-  display: inline-block;
-
-  transition: color .25s, background-color .25s;
-
-  &:hover {
-    color: $primary-color;
-    background-color: white;
+  .container {
+    display: flex;
+    justify-content: center;
+    flex-wrap: wrap;
  }

+  a {
+    padding: 0.25rem 0.75rem 0.25rem .75rem;
+    text-decoration: none;
+    color: black;
+    display: inline-block;
+    border-bottom: none;
+    white-space: nowrap;
+  }
 }

 .post-subscript {
  color: #8f8f8f;
+  text-align: center;
 }

 .post-content {
@@ -122,8 +150,14 @@ h6 {
 }

 a {
-  color: $primary-color-dark;
+  color: black;
  text-decoration: none;
+  border-bottom: .2rem solid $primary-color;
+  transition: color 0.25s;
+
+  &:hover {
+    color: $primary-color;
+  }
 }

 img {
@@ -150,6 +184,61 @@ td {
    padding: 0.5rem;
 }

+div.highlight tr {
+    display: table-row;
+}
+
+hr.header-divider {
+    background-color: $primary-color;
+    height: 0.3rem;
+    border: none;
+    border-radius: 0.15rem;
+}
+
+ul.post-list {
+    list-style: none;
+    padding: 0;
+
+    li {
+        @include bordered-block;
+        margin-bottom: 1rem;
+        padding: 1rem;
+    }
+
+    p {
+        margin: 0;
+    }
+
+    a.post-title {
+        border-bottom: none;
+        font-size: 1.4rem;
+        font-family: $font-heading;
+        text-align: center;
+        display: block;
+    }
+
+    p.post-wordcount {
+        text-align: center;
+        margin-bottom: 0.6rem;
+    }
+}
+
 .katex-html {
    white-space: nowrap;
 }
+
+figure {
+    img {
+        max-width: 70%;
+        display: block;
+        margin: auto;
+
+        @include below-container-width {
+            max-width: 100%;
+        }
+    }
+
+    figcaption {
+        text-align: center;
+    }
+}
--- a/themes/vanilla/assets/scss/toc.scss
+++ b/themes/vanilla/assets/scss/toc.scss
@@ -0,0 +1,49 @@
+@import "variables.scss";
+@import "mixins.scss";
+
+$toc-color: $code-color;
+$toc-border-color: $code-border-color;
+
+.table-of-contents {
+    @include margin-content;
+    @include margin-content-left;
+    display: flex;
+    flex-direction: column;
+    align-items: end;
+    margin-bottom: 1rem;
+
+    em {
+        font-style: normal;
+        font-weight: bold;
+        font-size: 1.2em;
+        display: block;
+        margin-bottom: 0.5rem;
+    }
+
+    #TableOfContents > ul {
+        padding-left: 0;
+    }
+
+    nav {
+        margin: 0px;
+    }
+
+    ul {
+        list-style: none;
+        padding-left: 2rem;
+        margin: 0px;
+    }
+
+    a {
+        padding: 0;
+    }
+
+    div.wrapper {
+        @include bordered-block;
+        padding: 1rem;
+        background-color: $toc-color;
+        border-color: $toc-border-color;
+        box-sizing: border-box;
+        max-width: 100%;
+    }
+}
--- a/themes/vanilla/assets/scss/variables.scss
+++ b/themes/vanilla/assets/scss/variables.scss
@@ -1,14 +1,16 @@
 $container-width: 45rem;
+$container-min-padding: 1rem;
+$container-width-threshold: $container-width + 2 * $container-min-padding;
 $standard-border-width: .075rem;

 $primary-color: #36e281;
-$primary-color-dark: darken($primary-color, 10%);
-$code-color: #f0f0f0;
-$code-color-dark: darken($code-color, 10%);
 $border-color: #bfbfbf;
+$code-color: #f0f0f0;
+$code-border-color: darken($code-color, 10%);

 $font-heading: "Lora", serif;
 $font-body: "Raleway", serif;
 $font-code: "Inconsolata", monospace;

 $standard-border: $standard-border-width solid $border-color;
+$code-border: $standard-border-width solid $code-border-color;
--- a/themes/vanilla/layouts/_default/baseof.html
+++ b/themes/vanilla/layouts/_default/baseof.html
@@ -3,6 +3,7 @@
    {{- partial "head.html" . -}}
    <body>
        {{- partial "header.html" . -}}
+        <div class="container"><hr class="header-divider"></div>
        <main class="container">
        {{- block "main" . }}{{- end }}
        </main>
--- a/themes/vanilla/layouts/_default/list.html
+++ b/themes/vanilla/layouts/_default/list.html
@@ -1,9 +1,9 @@
 {{ define "main" }}
 <h2>{{ .Title }}</h2>

-<ul>
+<ul class="post-list">
    {{ range .Pages.ByDate.Reverse }}
-    <li><a href="{{ .Permalink }}">{{ .Title }}</a></li>
+    {{ partial "post.html" . }}
    {{ end }}
 </ul>
 {{ end }}
--- a/themes/vanilla/layouts/blog/single.html
+++ b/themes/vanilla/layouts/blog/single.html
@@ -1,15 +1,23 @@
 {{ define "main" }}
 <h2>{{ .Title }}</h2>
 <div class="post-subscript">
-    <p>Posted on {{ .Date.Format "January 2, 2006" }}.</p>
-    <p>Tags:
+    <p>
        {{ range .Params.tags }}
        <a class="button" href="{{ $.Site.BaseURL }}/tags/{{ . | urlize }}">{{ . }}</a>
        {{ end }}
    </p>
+    <p>Posted on {{ .Date.Format "January 2, 2006" }}.</p>
 </div>

 <div class="post-content">
+    {{ if not (eq .TableOfContents "<nav id=\"TableOfContents\"></nav>") }}
+    <div class="table-of-contents">
+        <div class="wrapper">
+            <em>Table of Contents</em>
+            {{ .TableOfContents }}
+        </div>
+    </div>
+    {{ end }}
    {{ .Content }}
 </div>
 {{ end }}
--- a/themes/vanilla/layouts/index.html
+++ b/themes/vanilla/layouts/index.html
@@ -2,9 +2,9 @@
 {{ .Content }}

 Recent posts:
-<ul>
-{{ range first 10 (where (where .Site.Pages.ByDate.Reverse "Section" "blog") ".Kind" "!=" "section") }}
-<li><a href="{{ .Permalink }}">{{ .Title }}</a></li>
-{{ end }}
+<ul class="post-list">
+    {{ range first 10 (where (where .Site.Pages.ByDate.Reverse "Section" "blog") ".Kind" "!=" "section") }}
+    {{ partial "post.html" . }}
+    {{ end }}
 </ul>
 {{ end }}
--- a/themes/vanilla/layouts/partials/head.html
+++ b/themes/vanilla/layouts/partials/head.html
@@ -1,19 +1,21 @@
 <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
-    <meta name="theme-color" content="#1dc868" />
+    <meta name="theme-color" content="#1dc868">
+    {{ if .Description }}
+    <meta name="description" content="{{ .Description }}">
+    {{ end }}

-    <link href="https://fonts.googleapis.com/css?family=Inconsolata|Lora|Raleway" rel="stylesheet">
-    <link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/normalize/5.0.0/normalize.min.css">
+    <link rel="stylesheet" href="https://fonts.googleapis.com/css2?family=Inconsolata&family=Raleway&family=Lora&display=block" media="screen"> 
+    <link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/normalize/5.0.0/normalize.min.css" media="screen">
    {{ $style := resources.Get "scss/style.scss" | resources.ToCSS | resources.Minify }}
    {{ $sidenotes := resources.Get "scss/sidenotes.scss" | resources.ToCSS | resources.Minify }}
    {{ $icon := resources.Get "img/favicon.png" }}
    {{- partial "sidenotes.html" . -}}
-    <link rel="stylesheet" href="{{ $style.Permalink }}">
-    <link rel="stylesheet" href="{{ $sidenotes.Permalink }}">
+    <link rel="stylesheet" href="{{ $style.Permalink }}" media="screen">
+    <link rel="stylesheet" href="{{ $sidenotes.Permalink }}" media="screen">
+    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@0.11.1/dist/katex.min.css" integrity="sha384-zB1R0rpPzHqg7Kpt0Aljp8JPLqbXI3bhnPWROx27a9N0Ll6ZP/+DiW/UqRcLbRjq" crossorigin="anonymous" media="screen">
    <link rel="icon" type="image/png" href="{{ $icon.Permalink }}">

-    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@0.11.1/dist/katex.min.css" integrity="sha384-zB1R0rpPzHqg7Kpt0Aljp8JPLqbXI3bhnPWROx27a9N0Ll6ZP/+DiW/UqRcLbRjq" crossorigin="anonymous">
-
    <title>{{ .Title }}</title>
 </head>
--- a/themes/vanilla/layouts/partials/post.html
+++ b/themes/vanilla/layouts/partials/post.html
@@ -0,0 +1,5 @@
+<li>
+    <a href="{{ .Permalink }}" class="post-title">{{ .Title }}</a>
+    <p class="post-wordcount">{{ .WordCount }} words, about {{ .ReadingTime }} minutes to read.</p>
+    <p class="post-preview">{{ .Summary }} . . .</p>
+</li>
--- a/themes/vanilla/layouts/shortcodes/codelines.html
+++ b/themes/vanilla/layouts/shortcodes/codelines.html
@@ -6,4 +6,4 @@
 {{ .Scratch.Set "u" $t }}
 {{ end }}
 {{ $v := first (add (sub (int (.Get 3)) (int (.Get 2))) 1) (.Scratch.Get "u") }}
-{{ highlight (delimit $v "\n") (.Get 0) "" }}
+{{ highlight (delimit $v "\n") (.Get 0) (printf "linenos=table,linenostart=%d" (.Get 2)) }}
--- a/themes/vanilla/layouts/tags/list.html
+++ b/themes/vanilla/layouts/tags/list.html
@@ -1,9 +1,9 @@
 {{ define "main" }}
 <h2>Tagged "{{ .Title }}"</h2>

-<ul>
+<ul class="post-list">
    {{ range .Pages.ByDate.Reverse }}
-    <li><a href="{{ .Permalink }}">{{ .Title }}</a></li>
+    {{ partial "post.html" . }}
    {{ end }}
 </ul>
 {{ end }}
Author	SHA1	Message	Date
Danila Fedorin	e7d56dd4bd	Clean up some styles.	2020-07-15 13:56:03 -07:00
Danila Fedorin	a4fedb276d	Adjust margin spacing.	2020-07-15 13:18:34 -07:00
Danila Fedorin	277c0a2ce6	Rework sidenote spacing and TOC.	2020-07-15 13:13:47 -07:00
Danila Fedorin	ef3c61e9e6	Make table of contents dark.	2020-06-30 22:15:22 -07:00
Danila Fedorin	1908126607	Add border to code.	2020-06-30 21:31:16 -07:00
Danila Fedorin	2d77f8489f	Move hiding code into margin SCSS.	2020-06-30 21:22:19 -07:00
Danila Fedorin	0371651fdd	Fix headings on Starbound post.	2020-06-24 23:01:35 -07:00
Danila Fedorin	01734d24f7	Get started on tables of contents.	2020-06-24 22:46:22 -07:00
Danila Fedorin	71fc0546e0	Move move code into common 'margin node' mixin.	2020-06-24 22:06:08 -07:00
Danila Fedorin	871a745702	Extract margin variables and mixins into separate file.	2020-06-24 14:21:56 -07:00
Danila Fedorin	3f0df8ae0d	Add links for 12th part of compiler series.	2020-06-21 22:21:43 -07:00
Danila Fedorin	1746011c16	Publish 12th part of compiler series.	2020-06-21 00:51:04 -07:00
Danila Fedorin	7c4cfbf3d4	Fix typechecking of mutually recursive functions.	2020-06-21 00:47:26 -07:00
Danila Fedorin	8524e098a8	Make proofreading-based fixes.	2020-06-20 23:50:26 -07:00
Danila Fedorin	971f58da9b	Finish draft of part 12 of compiler series.	2020-06-20 22:03:57 -07:00
Danila Fedorin	c496be1031	Finish implementation description in part 12.	2020-06-20 20:46:54 -07:00
Danila Fedorin	21851e3a9c	Add more content to part 12.	2020-06-19 02:22:08 -07:00
Danila Fedorin	600d5b91ea	Remove unneeded parent class.	2020-06-18 23:06:13 -07:00
Danila Fedorin	09b90c3bbc	Add line numbers to codelines shortode.	2020-06-18 22:30:01 -07:00
Danila Fedorin	f6ca13d6dc	Add more implementation content to part 12.	2020-06-18 22:29:38 -07:00
Danila Fedorin	9c4d7c514f	Add more content to post 12 draft.	2020-06-16 23:32:09 -07:00
Danila Fedorin	ad1946e9fb	Add first draft of lambdas.	2020-06-14 02:00:20 -07:00
Danila Fedorin	68910458e8	Properly handle null types in pattern typechecking.	2020-06-14 00:43:39 -07:00
Danila Fedorin	240e87eca4	Use mangled names in variable environments.	2020-06-13 23:43:52 -07:00
Danila Fedorin	6b5f7e25b7	Maybe finish the let/in code?	2020-06-01 00:23:41 -07:00
Danila Fedorin	e7229e644f	Start working on translation.	2020-05-31 18:52:52 -07:00
Danila Fedorin	08c8aca144	Start working on a lifted version of a definition.	2020-05-31 14:37:33 -07:00
Danila Fedorin	7f8dae74ac	Adjust type output.	2020-05-31 00:50:58 -07:00
Danila Fedorin	08503116ff	Mark some definitions as global, so as not to capture them.	2020-05-31 00:34:12 -07:00
Danila Fedorin	a1d679a59d	No longer destroy the list of free variables. It so happens that this list will tell us which variables need to be captured.	2020-05-30 23:29:36 -07:00
Danila Fedorin	4586bd0188	Check for free variables in the environment before generalizing.	2020-05-30 16:40:27 -07:00
Danila Fedorin	a97b50f497	Add parsing of let/in.	2020-05-28 14:44:12 -07:00
Danila Fedorin	c84ff11d0d	Add typechecking to let/in expressions.	2020-05-26 00:52:54 -07:00
Danila Fedorin	e966e74487	Extract ordering functionality into definition group.	2020-05-25 23:58:56 -07:00
Danila Fedorin	3865abfb4d	Add a struct to contain groups of mutually recursive definitions.	2020-05-25 22:11:45 -07:00
Danila Fedorin	1905601aaa	Fork off the 12th version of the compiler.	2020-05-25 21:20:41 -07:00
Danila Fedorin	aacb9e2874	Prefer invisible text to unstyled text.	2020-05-25 20:55:20 -07:00
Danila Fedorin	78f3b18969	Increase padding in post lists.	2020-05-17 22:00:10 -07:00
Danila Fedorin	9f73ca2950	Remove bold font weight on post lists. Some checks failed continuous-integration/drone/push Build is failing Details	2020-05-09 17:53:55 -07:00
Danila Fedorin	035b98a602	Start using description meta. Some checks failed continuous-integration/drone/push Build is failing Details	2020-05-09 17:29:57 -07:00
Danila Fedorin	17f4ebc297	Add media screen to all stylesheets.	2020-05-09 17:02:13 -07:00
Danila Fedorin	906e15674e	Make minor edits to the content	2020-05-09 16:52:05 -07:00
Danila Fedorin	85bd0b6c9c	Switch to left-alignment on small screens to prevent ugly gaps. Some checks failed continuous-integration/drone/push Build is failing Details	2020-05-09 01:48:22 -07:00
Danila Fedorin	b19e8713e0	Center post titles and word counters.	2020-05-09 01:45:53 -07:00
Danila Fedorin	68fb78e765	Only left-justify post titles	2020-05-09 01:41:10 -07:00
Danila Fedorin	be8a0a4a3a	Left jusify text in links to prevent random variation Some checks failed continuous-integration/drone/push Build is failing Details	2020-05-04 19:55:48 -07:00
Danila Fedorin	e883e3c60e	Update link lists to visually indicate they're links. Some checks failed continuous-integration/drone/push Build is failing Details	2020-05-04 19:25:03 -07:00
Danila Fedorin	4ede62b39a	Stop displaying links in bold. Some checks failed continuous-integration/drone/push Build is failing Details	2020-05-04 03:56:21 -07:00
Danila Fedorin	7d9f487a78	Stop using revert due to Chrome issues Some checks failed continuous-integration/drone/push Build is failing Details	2020-05-04 03:47:53 -07:00
Danila Fedorin	9da584ded4	Make page lists bold Some checks failed continuous-integration/drone/push Build is failing Details	2020-05-04 03:36:23 -07:00
Danila Fedorin	9452c90cf3	Switch back to Raleway	2020-05-04 03:35:24 -07:00
Danila Fedorin	a80064f40a	Merge branch 'master' of https://dev.danilafe.com/Web-Projects/blog-static	2020-05-04 03:29:48 -07:00
Danila Fedorin	49691803cc	Stop displaying links as inline-block	2020-05-04 03:28:17 -07:00
Danila Fedorin	ee4738b245	Add redesign CSS	2020-05-04 03:23:55 -07:00
Danila Fedorin	b270fa78da	Add draft of lazy evaluation post	2020-05-04 01:58:25 -07:00
Danila Fedorin	18339d7e4d	Build and test version 11 of the compiler instead of 10. Some checks failed continuous-integration/drone/push Build is failing Details	2020-04-26 21:28:34 -07:00
Danila Fedorin	78563448fb	Update to LLVM 10. Some checks failed continuous-integration/drone/push Build is failing Details	2020-04-26 21:24:24 -07:00
Danila Fedorin	144d5f3324	Try to fix compiler build failure Some checks failed continuous-integration/drone/push Build is failing Details	2020-04-26 21:05:28 -07:00
Danila Fedorin	0fb315ec47	Prevent single-column tables in the case of highlighting Some checks failed continuous-integration/drone/push Build is failing Details	2020-04-26 20:47:51 -07:00
Danila Fedorin	1ff67341a1	Disable live uploading while the new server doesn't accept the files. Some checks failed continuous-integration/drone/push Build is failing Details	2020-04-26 19:57:50 -07:00
Danila Fedorin	a441280812	Add article about Crystal and Nix with OpenSSL. Some checks failed continuous-integration/drone/push Build is failing Details	2020-04-26 19:56:15 -07:00
Danila Fedorin	eda9bbb191	Add more to part 12 of compiler series	2020-04-25 18:07:32 -07:00
Danila Fedorin	2d9da2899f	Switch to no line breaks (for Ghostwriter support)	2020-04-25 15:45:15 -07:00
Danila Fedorin	a95490d9d4	Add more content to part 12 of compiler series Some checks failed continuous-integration/drone/push Build is failing Details	2020-04-22 00:30:42 -07:00
Danila Fedorin	44135b1824	Add experimental figure-based styles	2020-04-22 00:30:22 -07:00