code/compiler/06/CMakeLists.txt

@@ -1,26 +0,0 @@
-cmake_minimum_required(VERSION 3.1)
-project(compiler)
-
-find_package(BISON)
-find_package(FLEX)
-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)
-
-add_executable(compiler
-    ast.cpp ast.hpp definition.cpp
-    type_env.cpp type_env.hpp
-    env.cpp env.hpp
-    type.cpp type.hpp
-    error.cpp error.hpp
-    ${BISON_parser_OUTPUTS}
-    ${FLEX_scanner_OUTPUTS}
-    main.cpp
-)
-target_include_directories(compiler PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
-target_include_directories(compiler PUBLIC ${CMAKE_CURRENT_BINARY_DIR})

code/compiler/06/ast.cpp

@@ -1,144 +0,0 @@
-#include "ast.hpp"
-#include <ostream>
-#include "error.hpp"
-
-std::string op_name(binop op) {
-    switch(op) {
-        case PLUS: return "+";
-        case MINUS: return "-";
-        case TIMES: return "*";
-        case DIVIDE: return "/";
-    }
-    return "??";
-}
-
-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;
-}
-
-type_ptr ast_int::typecheck(type_mgr& mgr, const type_env& env) const {
-    return type_ptr(new type_base("Int"));
-}
-
-void ast_lid::print(int indent, std::ostream& to) const {
-    print_indent(indent, to);
-    to << "LID: " << id << std::endl;
-}
-
-type_ptr ast_lid::typecheck(type_mgr& mgr, const type_env& env) const {
-    return env.lookup(id);
-}
-
-void ast_uid::print(int indent, std::ostream& to) const {
-    print_indent(indent, to);
-    to << "UID: " << id << std::endl;
-}
-
-type_ptr ast_uid::typecheck(type_mgr& mgr, const type_env& env) const {
-    return env.lookup(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);
-}
-
-type_ptr ast_binop::typecheck(type_mgr& mgr, const type_env& env) const {
-    type_ptr ltype = left->typecheck(mgr, env);
-    type_ptr rtype = right->typecheck(mgr, env);
-    type_ptr ftype = env.lookup(op_name(op));
-    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_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);
-}
-
-type_ptr ast_app::typecheck(type_mgr& mgr, const type_env& env) const {
-    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_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);
-    }
-}
-
-type_ptr ast_case::typecheck(type_mgr& mgr, const type_env& env) const {
-    type_var* var;
-    type_ptr case_type = mgr.resolve(of->typecheck(mgr, env), var);
-    type_ptr branch_type = mgr.new_type();
-
-    if(!dynamic_cast<type_base*>(case_type.get())) {
-        throw type_error("attempting case analysis of non-data type");
-    }
-
-    for(auto& branch : branches) {
-        type_env new_env = env.scope();
-        branch->pat->match(case_type, mgr, new_env);
-        type_ptr curr_branch_type = branch->expr->typecheck(mgr, new_env);
-        mgr.unify(branch_type, curr_branch_type);
-    }
-
-    return branch_type;
-}
-
-void pattern_var::print(std::ostream& to) const {
-    to << var;
-}
-
-void pattern_var::match(type_ptr t, type_mgr& mgr, type_env& 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::match(type_ptr t, type_mgr& mgr, type_env& env) const {
-    type_ptr constructor_type = env.lookup(constr);
-    if(!constructor_type) {
-        throw type_error(std::string("pattern using unknown constructor ") + constr);
-    }
-
-    for(int i = 0; i < params.size(); i++) {
-        type_arr* arr = dynamic_cast<type_arr*>(constructor_type.get());
-        if(!arr) throw type_error("too many parameters in constructor pattern");
-
-        env.bind(params[i], arr->left);
-        constructor_type = arr->right;
-    }
-
-    mgr.unify(t, constructor_type);
-}

code/compiler/06/ast.hpp

@@ -1,170 +0,0 @@
-#pragma once
-#include <memory>
-#include <vector>
-#include "type.hpp"
-#include "type_env.hpp"
-#include "binop.hpp"
-#include "instruction.hpp"
-#include "env.hpp"
-
-struct ast {
-    virtual ~ast() = default;
-
-    virtual void print(int indent, std::ostream& to) const = 0;
-    virtual type_ptr typecheck(type_mgr& mgr, const type_env& env) const = 0;
-    virtual void compile(const env_ptr env,
-            std::vector<instruction>& into) const;
-};
-
-using ast_ptr = std::unique_ptr<ast>;
-
-struct pattern {
-    virtual ~pattern() = default;
-
-    virtual void print(std::ostream& to) const = 0;
-    virtual void match(type_ptr t, type_mgr& mgr, type_env& 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 constructor {
-    std::string name;
-    std::vector<std::string> types;
-
-    constructor(std::string n, std::vector<std::string> ts)
-        : name(std::move(n)), types(std::move(ts)) {}
-};
-
-using constructor_ptr = std::unique_ptr<constructor>;
-
-struct definition {
-    virtual ~definition() = default;
-    
-    virtual void typecheck_first(type_mgr& mgr, type_env& env) = 0;
-    virtual void typecheck_second(type_mgr& mgr, const type_env& env) const = 0;
-};
-
-using definition_ptr = std::unique_ptr<definition>;
-
-struct ast_int : public ast {
-    int value;
-
-    explicit ast_int(int v)
-        : value(v) {}
-
-    void print(int indent, std::ostream& to) const;
-    type_ptr typecheck(type_mgr& mgr, const type_env& env) 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;
-    type_ptr typecheck(type_mgr& mgr, const type_env& env) 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;
-    type_ptr typecheck(type_mgr& mgr, const type_env& env) 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;
-    type_ptr typecheck(type_mgr& mgr, const type_env& env) 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;
-    type_ptr typecheck(type_mgr& mgr, const type_env& env) const;
-};
-
-struct ast_case : public ast {
-    ast_ptr of;
-    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;
-    type_ptr typecheck(type_mgr& mgr, const type_env& env) 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 match(type_ptr t, type_mgr& mgr, type_env& 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 match(type_ptr t, type_mgr&, type_env& env) const;
-};
-
-struct definition_defn : public definition {
-    std::string name;
-    std::vector<std::string> params;
-    ast_ptr body;
-
-    type_ptr return_type;
-    std::vector<type_ptr> param_types;
-
-    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 typecheck_first(type_mgr& mgr, type_env& env);
-    void typecheck_second(type_mgr& mgr, const type_env& env) const;
-};
-
-struct definition_data : public definition {
-    std::string name;
-    std::vector<constructor_ptr> constructors;
-
-    definition_data(std::string n, std::vector<constructor_ptr> cs)
-        : name(std::move(n)), constructors(std::move(cs)) {}
-
-    void typecheck_first(type_mgr& mgr, type_env& env);
-    void typecheck_second(type_mgr& mgr, const type_env& env) const;
-};

code/compiler/06/binop.hpp

@@ -1,9 +0,0 @@
-#pragma once
-
-enum binop {
-    PLUS,
-    MINUS,
-    TIMES,
-    DIVIDE
-};
-

code/compiler/06/definition.cpp

@@ -1,48 +0,0 @@
-#include "ast.hpp"
-
-void definition_defn::typecheck_first(type_mgr& mgr, type_env& env) {
-    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();
-        full_type = type_ptr(new type_arr(param_type, full_type));
-        param_types.push_back(param_type);
-    }
-
-    env.bind(name, full_type);
-}
-
-void definition_defn::typecheck_second(type_mgr& mgr, const type_env& env) const {
-    type_env new_env = env.scope();
-    auto param_it = params.begin();
-    auto type_it = param_types.rbegin();
-
-    while(param_it != params.end() && type_it != param_types.rend()) {
-        new_env.bind(*param_it, *type_it);
-        param_it++;
-        type_it++;
-    }
-
-    type_ptr body_type = body->typecheck(mgr, new_env);
-    mgr.unify(return_type, body_type);
-}
-
-void definition_data::typecheck_first(type_mgr& mgr, type_env& env) {
-    type_ptr return_type = type_ptr(new type_base(name));
-
-    for(auto& constructor : constructors) {
-        type_ptr full_type = return_type;
-
-        for(auto it = constructor->types.rbegin(); it != constructor->types.rend(); it++) {
-            type_ptr type = type_ptr(new type_base(*it));
-            full_type = type_ptr(new type_arr(type, full_type));
-        }
-
-        env.bind(constructor->name, full_type);
-    }
-}
-
-void definition_data::typecheck_second(type_mgr& mgr, const type_env& env) const {
-    // Nothing
-}

code/compiler/06/env.hpp

@@ -1,31 +0,0 @@
-#pragma once
-#include <memory>
-#include <string>
-
-struct env {
-    virtual ~env() = default;
-
-    virtual int get_offset(const std::string& name) const = 0;
-};
-
-using env_ptr = std::shared_ptr<env>;
-
-struct env_var {
-    std::string name;
-    env_ptr parent;
-
-    env_var(std::string& n, env_ptr p)
-        : name(std::move(n)), parent(std::move(p)) {}
-
-    virtual int get_offset(const std::string& name) const;
-};
-
-struct env_offset {
-    int offset;
-    env_ptr parent;
-
-    env_offset(int o, env_ptr p)
-        : offset(o), parent(std::move(p)) {}
-
-    virtual int get_offset(const std::string& name) const;
-};

code/compiler/06/error.cpp

@@ -1,5 +0,0 @@
-#include "error.hpp"
-
-const char* type_error::what() const noexcept {
-    return "an error occured while checking the types of the program";
-}

code/compiler/06/error.hpp

@@ -1,21 +0,0 @@
-#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") {}
-};

code/compiler/06/examples/bad1.txt

@@ -1,2 +0,0 @@
-data Bool = { True, False }
-defn main = { 3 + True }

code/compiler/06/examples/bad2.txt

@@ -1 +0,0 @@
-defn main = { 1 2 3 4 5 }

code/compiler/06/examples/bad3.txt

@@ -1,8 +0,0 @@
-data List = { Nil, Cons Int List }
-
-defn head l = {
-    case l of {
-        Nil -> { 0 }
-        Cons x y z -> { x }
-    }
-}

code/compiler/06/examples/works1.txt

@@ -1,2 +0,0 @@
-defn main = { plus 320 6 }
-defn plus x y = { x + y }

code/compiler/06/examples/works2.txt

@@ -1,3 +0,0 @@
-defn add x y = { x + y }
-defn double x = { add x x }
-defn main = { double 163 }

code/compiler/06/examples/works3.txt

@@ -1,7 +0,0 @@
-data List = { Nil, Cons Int List }
-defn length l = {
-    case l of {
-        Nil -> { 0 }
-        Cons x xs -> { 1 + length xs }
-    }
-}

code/compiler/06/instruction.hpp

@@ -1,83 +0,0 @@
-#pragma once
-#include <string>
-#include <memory>
-#include "binop.hpp"
-
-struct instruction {
-    virtual ~instruction() = default;
-};
-
-using instruction_ptr = std::unique_ptr<instruction>;
-
-struct instruction_pushint : public instruction {
-    int value;
-
-    instruction_pushint(int v)
-        : value(v) {}
-};
-
-struct instruction_pushglobal : public instruction {
-    std::string name;
-
-    instruction_pushglobal(std::string n)
-        : name(std::move(n)) {}
-};
-
-struct instruction_push : public instruction {
-    int offset;
-
-    instruction_push(int o)
-        : offset(o) {}
-};
-
-struct instruction_mkapp : public instruction {
-
-};
-
-struct instruction_update : public instruction {
-    int offset;
-
-    instruction_update(int o)
-        : offset(o) {}
-};
-
-struct instruction_pack : public instruction {
-    int tag;
-    int size;
-
-    instruction_pack(int t, int s)
-        : tag(t), size(s) {}
-};
-
-struct instruction_split : public instruction {
-    
-};
-
-struct instruction_slide : public instruction {
-    int offset;
-
-    instruction_slide(int o)
-        : offset(o) {}
-};
-
-struct instruction_binop : public instruction {
-    binop op;
-
-    instruction_binop(binop o)
-        : op(o) {}
-};
-
-struct instruction_eval : public instruction {
-    
-};
-
-struct instruction_alloc : public instruction {
-    int amount;
-
-    instruction_alloc(int a)
-        : amount(a) {}
-};
-
-struct instruction_unwind : public instruction {
-
-};

code/compiler/06/main.cpp

@@ -1,70 +0,0 @@
-#include "ast.hpp"
-#include <iostream>
-#include "parser.hpp"
-#include "error.hpp"
-#include "type.hpp"
-
-void yy::parser::error(const std::string& msg) {
-    std::cout << "An error occured: " << msg << std::endl;
-}
-
-extern std::vector<definition_ptr> program;
-
-void typecheck_program(
-        const std::vector<definition_ptr>& prog,
-        type_mgr& mgr, type_env& env) {
-    type_ptr int_type = type_ptr(new type_base("Int")); 
-    type_ptr binop_type = type_ptr(new type_arr(
-                int_type,
-                type_ptr(new type_arr(int_type, int_type))));
-
-    env.bind("+", binop_type);
-    env.bind("-", binop_type);
-    env.bind("*", binop_type);
-    env.bind("/", binop_type);
-
-    for(auto& def : prog) {
-        def->typecheck_first(mgr, env);
-    }
-
-    for(auto& def : prog) {
-        def->typecheck_second(mgr, env);
-    }
-
-    for(auto& pair : env.names) {
-        std::cout << pair.first << ": ";
-        pair.second->print(mgr, std::cout);
-        std::cout << std::endl;
-    }
-}
-
-int main() {
-    yy::parser parser;
-    type_mgr mgr;
-    type_env env;
-
-    parser.parse();
-    for(auto& definition : program) {
-        definition_defn* def = dynamic_cast<definition_defn*>(definition.get());
-        if(!def) continue;
-
-        std::cout << def->name;
-        for(auto& param : def->params) std::cout << " " << param;
-        std::cout << ":" << std::endl;
-
-        def->body->print(1, std::cout);
-    }
-    try {
-        typecheck_program(program, mgr, env);
-    } 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;
-    }
-}

code/compiler/06/parser.y

@@ -1,140 +0,0 @@
-%{
-#include <string>
-#include <iostream>
-#include "ast.hpp"
-#include "parser.hpp"
-
-std::vector<definition_ptr> program;
-extern yy::parser::symbol_type yylex();
-
-%}
-
-%token PLUS
-%token TIMES
-%token MINUS
-%token DIVIDE
-%token <int> INT
-%token DEFN
-%token DATA
-%token CASE
-%token OF
-%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 uppercaseParams
-%type <std::vector<definition_ptr>> program definitions
-%type <std::vector<branch_ptr>> branches
-%type <std::vector<constructor_ptr>> constructors
-%type <ast_ptr> aAdd aMul case app appBase
-%type <definition_ptr> definition defn data 
-%type <branch_ptr> branch
-%type <pattern_ptr> pattern
-%type <constructor_ptr> constructor
-
-%start program
-
-%%
-
-program
-    : definitions { program = std::move($1); }
-    ;
-
-definitions
-    : definitions definition { $$ = std::move($1); $$.push_back(std::move($2)); }
-    | definition { $$ = std::vector<definition_ptr>(); $$.push_back(std::move($1)); }
-    ;
-
-definition
-    : defn { $$ = std::move($1); }
-    | data { $$ = std::move($1); }
-    ;
-
-defn
-    : DEFN LID lowercaseParams EQUAL OCURLY aAdd CCURLY
-        { $$ = definition_ptr(
-            new definition_defn(std::move($2), std::move($3), std::move($6))); }
-    ;
-
-lowercaseParams
-    : %empty { $$ = std::vector<std::string>(); }
-    | lowercaseParams LID { $$ = std::move($1); $$.push_back(std::move($2)); }
-    ;
-
-uppercaseParams
-    : %empty { $$ = std::vector<std::string>(); }
-    | uppercaseParams UID { $$ = 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); }
-    ;
-
-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 EQUAL OCURLY constructors CCURLY
-        { $$ = definition_ptr(new definition_data(std::move($2), std::move($5))); }
-    ;
-
-constructors
-    : constructors COMMA constructor { $$ = std::move($1); $$.push_back(std::move($3)); }
-    | constructor
-        { $$ = std::vector<constructor_ptr>(); $$.push_back(std::move($1)); }
-    ;
-
-constructor
-    : UID uppercaseParams
-        { $$ = constructor_ptr(new constructor(std::move($1), std::move($2))); }
-    ;
-

code/compiler/06/scanner.l

@@ -1,34 +0,0 @@
-%option noyywrap
-
-%{
-#include <iostream>
-#include "ast.hpp"
-#include "parser.hpp"
-
-#define YY_DECL yy::parser::symbol_type yylex()
-
-%}
-
-%%
-
-[ \n]+ {}
-\+ { 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(); }
-\{ { 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)); }
-
-%%

code/compiler/06/type.cpp

@@ -1,99 +0,0 @@
-#include "type.hpp"
-#include <sstream>
-#include <algorithm>
-#include "error.hpp"
-
-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;
-    }
-}
-
-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 {
-    left->print(mgr, to);
-    to << " -> (";
-    right->print(mgr, to);
-    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) {
-    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;
-    type_var* rvar;
-    type_arr* larr;
-    type_arr* rarr;
-    type_base* lid;
-    type_base* rid;
-
-    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) return;
-    }
-
-    throw unification_error(l, r);
-}
-
-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;
-}

code/compiler/06/type.hpp

@@ -1,54 +0,0 @@
-#pragma once
-#include <memory>
-#include <map>
-
-struct type_mgr;
-
-struct type {
-    virtual ~type() = default;
-
-    virtual void print(const type_mgr& mgr, std::ostream& to) const = 0;
-};
-
-using type_ptr = std::shared_ptr<type>;
-
-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;
-};
-
-struct type_base : public type {
-    std::string name;
-
-    type_base(std::string n) 
-        : name(std::move(n)) {}
-
-    void print(const type_mgr& mgr, std::ostream& to) const;
-};
-
-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;
-};
-
-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 resolve(type_ptr t, type_var*& var);
-    void bind(const std::string& s, type_ptr t);
-};

code/compiler/06/type_env.cpp

@@ -1,16 +0,0 @@
-#include "type_env.hpp"
-
-type_ptr type_env::lookup(const std::string& name) const {
-    auto it = names.find(name);
-    if(it != names.end()) return it->second;
-    if(parent) return parent->lookup(name);
-    return nullptr;
-}
-
-void type_env::bind(const std::string& name, type_ptr t) {
-    names[name] = t;
-}
-
-type_env type_env::scope() const {
-    return type_env(this);
-}

code/compiler/06/type_env.hpp

@@ -1,16 +0,0 @@
-#pragma once
-#include <map>
-#include "type.hpp"
-
-struct type_env {
-    std::map<std::string, type_ptr> names;
-    type_env const* parent = nullptr;
-
-    type_env(type_env const* p)
-        : parent(p) {}
-    type_env() : type_env(nullptr) {}
-
-    type_ptr lookup(const std::string& name) const;
-    void bind(const std::string& name, type_ptr t);
-    type_env scope() const;
-};

content/blog/06_compiler_semantics.md

@@ -161,35 +161,9 @@ graphs when we have to instantiate those functions, we simply
 evaluate the arguments and perform the relevant arithmetic operation using BinOp.
 We will do a similar thing for constructors.
 
-### Implementation
+With that out of the way, we can get around to writing some code. We can envision
-
+a method on the `ast` struct that takes an environment (just like our compilation
-With that out of the way, we can get around to writing some code. Let's
+scheme takes the environment \\(\\rho\\\)). Rather than returning a vector
-first define C++ structs for the instructions of the G-machine:
-
-{{< codeblock "C++" "compiler/06/instruction.hpp" >}}
-
-We can now envision a method on the `ast` struct that takes an environment 
-(just like our compilation scheme takes the environment \\(\\rho\\\)),
-and compiles the `ast`. Rather than returning a vector
 of instructions (which involves copying, unless we get some optimization kicking in),
-we'll pass a reference to a vector to our method. The method will then place the generated
+we'll pass to it a reference to a vector. The method will then place the generated
 instructions into the vector.
-
-There's one more thing to be considered. How do we tell apart a "global"
-from a variable? A naive solution would be to take a list or map of
-global functions as a third parameter to our `compile` method.
-But there's an easier way! We know that the program passed type checking.
-This means that every referenced variable exists. From then, the situation is easy -
-if actual variable names are kept in the environment, \\(\\rho\\), then whenever
-we see a variable that __isn't__ in the current environment, it must be a function name.
-
-Having finished contemplating out method, it's time to define a signature:
-```C++
-virtual void compile(const env_ptr env, std::vector<instruction>& into) const;
-```
-
-Ah, but now we have to define "environment". Let's do that:
-
-{{< codeblock "C++" "compiler/06/env.hpp" >}}
-
-And now, we begin our implementation.