diff --git a/src/chalk.cr b/src/chalk.cr
index b42f081..0443cb5 100644
--- a/src/chalk.cr
+++ b/src/chalk.cr
@@ -1,12 +1,11 @@
 require "./chalk/*"
+require "option_parser"
 
 module Chalk
-  lexer = Lexer.new
-  parser = Parser.new
+  config = Config.parse!
+  exit unless config.validate!
 
-  tokens = lexer.lex(File.read("test.txt"))
-  trees = parser.parse?(tokens)
-  trees.try do |trees|
-      trees.each { |tree| puts tree }
-  end
+  generator = CodeGenerator.new (Table.new)
+  compiler = Compiler.new config
+  compiler.run
 end
diff --git a/src/chalk/codegen.cr b/src/chalk/codegen.cr
new file mode 100644
index 0000000..402d21f
--- /dev/null
+++ b/src/chalk/codegen.cr
@@ -0,0 +1,79 @@
+require "./ir.cr"
+
+module Chalk
+  class CodeGenerator
+    def initialize(@table : Table)
+      @register = 0
+      @instructions = [] of Instruction
+      @block_edges = [] of Int32
+    end
+
+    private def load(into, value)
+      @instructions << LoadInstruction.new into, value.to_i32
+    end
+
+    private def loadr(into, from)
+      @instructions << LoadRegInstruction.new into, from
+    end
+
+    private def op(op, into, from)
+      @instructions << OpRegInstruction.new op, into, from
+    end
+
+    private def store(up_to)
+      @instructions << StoreInstruction.new up_to
+    end
+
+    private def restore(up_to)
+      @instructions << RestoreInstruction.new up_to
+    end
+
+    private def ret(reg)
+      @instructions << ReturnInstruction.new reg
+    end
+
+    def generate(tree : Tree, target : Int32)
+      case tree
+      when TreeId
+        entry = @table[tree.id]?
+        raise "Unknown variable" unless entry &&
+                                        entry.is_a?(VarEntry)
+        loadr target, entry.as(VarEntry).register
+      when TreeLit
+        load target, tree.lit
+      when TreeOp
+        generate tree.left, target
+        generate tree.right, @register
+        op tree.op, target, @register
+      when TreeBlock
+        tree.children.each do |child|
+          generate child, @register
+        end
+      when TreeVar
+        entry = @table[tree.name]?
+        if entry == nil
+          entry = VarEntry.new @register
+          @register += 1
+          @table[tree.name] = entry
+        end
+        raise "Unknown variable" unless entry.is_a?(VarEntry)
+        generate tree.expr, entry.register
+      when TreeAssign
+        entry = @table[tree.name]?
+        raise "Unknown variable" unless entry &&
+                                        entry.is_a?(VarEntry)
+        generate tree.expr, entry.as(VarEntry).register
+      when TreeReturn
+        generate tree.rvalue, target
+        ret target
+      end
+    end
+
+    def generate(tree : Tree)
+      generate(tree, 0)
+      @block_edges << @instructions.size
+      @block_edges.sort!
+      return @instructions
+    end
+  end
+end
diff --git a/src/chalk/compiler.cr b/src/chalk/compiler.cr
new file mode 100644
index 0000000..840b1c0
--- /dev/null
+++ b/src/chalk/compiler.cr
@@ -0,0 +1,77 @@
+require "logger"
+require "./constant_folder.cr"
+require "./table.cr"
+
+module Chalk
+  class Compiler
+    def initialize(@config : Config)
+      @logger = Logger.new STDOUT
+      @lexer = Lexer.new
+      @parser = Parser.new
+      @logger.debug("Initialized compiler")
+      @logger.level = Logger::DEBUG
+    end
+
+    private def create_trees(file)
+      string = File.read(file)
+      tokens = @lexer.lex string
+      if tokens.size == 0 && string != ""
+        raise "Unable to tokenize file."
+      end
+      @logger.debug("Finished tokenizing")
+      if trees = @parser.parse?(tokens)
+        @logger.debug("Finished parsing")
+        return trees
+      end
+      raise "Unable to parse file."
+    end
+
+    private def process_initial(trees)
+      table = Table.new
+      folder = ConstantFolder.new
+      trees.each do |tree|
+        tree = tree.as(TreeFunction)
+        @logger.debug("Constant folding #{tree.name}")
+        tree = tree.apply(folder).as(TreeFunction)
+        @logger.debug("Storing #{tree.name} in symbol table")
+        table[tree.name] = FunctionEntry.new tree
+      end
+      return table
+    end
+
+    private def generate_code(trees, table)
+      trees.each do |tree|
+        generator = CodeGenerator.new table
+        instructions = generator.generate tree.as(TreeFunction).block
+        instructions.each { |it| puts it }
+      end
+    end
+
+    private def run_tree
+      trees = create_trees(@config.file)
+      trees.each do |it|
+        STDOUT << it
+      end
+    end
+
+    private def run_intermediate
+      trees = create_trees(@config.file)
+      table = process_initial(trees)
+      generate_code(trees, table)
+    end
+
+    private def run_binary
+    end
+
+    def run
+      case @config.mode
+      when OutputMode::Tree
+        run_tree
+      when OutputMode::Intermediate
+        run_intermediate
+      when OutputMode::Binary
+        run_binary
+      end
+    end
+  end
+end
diff --git a/src/chalk/constant_folder.cr b/src/chalk/constant_folder.cr
new file mode 100644
index 0000000..f5dc229
--- /dev/null
+++ b/src/chalk/constant_folder.cr
@@ -0,0 +1,33 @@
+require "./tree.cr"
+
+module Chalk
+  class ConstantFolder < Transformer
+    private def perform_op(op, left, right)
+      case op
+      when TokenType::OpAdd
+        left + right
+      when TokenType::OpSub
+        left - right
+      when TokenType::OpMul
+        left*right
+      when TokenType::OpDiv
+        left/right
+      when TokenType::OpAnd
+        left & right
+      when TokenType::OpOr
+        left | right
+      else TokenType::OpXor
+      left ^ right
+      end
+    end
+
+    def transform(tree : TreeOp)
+      if tree.left.is_a?(TreeLit) && tree.right.is_a?(TreeLit)
+        return TreeLit.new perform_op(tree.op,
+          tree.left.as(TreeLit).lit,
+          tree.right.as(TreeLit).lit)
+      end
+      return tree
+    end
+  end
+end
diff --git a/src/chalk/ir.cr b/src/chalk/ir.cr
new file mode 100644
index 0000000..a1959b5
--- /dev/null
+++ b/src/chalk/ir.cr
@@ -0,0 +1,103 @@
+require "./lexer.cr"
+
+module Chalk
+  class Instruction
+  end
+
+  class LoadInstruction < Instruction
+    property register : Int32
+    property value : Int32
+
+    def initialize(@register : Int32, @value : Int32)
+    end
+
+    def to_s(io)
+      io << "load R"
+      @register.to_s(16, io)
+      io << " " << @value
+    end
+  end
+
+  class LoadRegInstruction < Instruction
+    property into : Int32
+    property from : Int32
+
+    def initialize(@into : Int32, @from : Int32)
+    end
+
+    def to_s(io)
+      io << "loadr R"
+      @into.to_s(16, io)
+      io << " R"
+      @from.to_s(16, io)
+    end
+  end
+
+  class OpInstruction < Instruction
+    property op : TokenType
+    property into : Int32
+    property value : Int32
+
+    def initialize(@op : TokenType, @into : Int32,
+                   @value : Int32)
+    end
+
+    def to_s(io)
+      io << "op " << op << " R"
+      @into.to_s(16, io)
+      io << " " << @value
+    end
+  end
+
+  class OpRegInstruction < Instruction
+    property op : TokenType
+    property into : Int32
+    property from : Int32
+
+    def initialize(@op : TokenType, @into : Int32, @from : Int32)
+    end
+
+    def to_s(io)
+      io << "opr " << op << " R"
+      @into.to_s(16, io)
+      io << " R"
+      @from.to_s(16, io)
+    end
+  end
+
+  class StoreInstruction < Instruction
+    property up_to : Int32
+
+    def initialize(@up_to : Int32)
+    end
+
+    def to_s(io)
+      io << "store R"
+      @up_to.to_s(16, io)
+    end
+  end
+
+  class RestoreInstruction < Instruction
+    property up_to : Int32
+
+    def initialize(@up_to : Int32)
+    end
+
+    def to_s(io)
+      io << "restore R"
+      @up_to.to_s(16, io)
+    end
+  end
+
+  class ReturnInstruction < Instruction
+    property to_return : Int32
+
+    def initialize(@to_return : Int32)
+    end
+
+    def to_s(io)
+      io << "return R"
+      @to_return.to_s(16, io)
+    end
+  end
+end
diff --git a/src/chalk/print_visitor.cr b/src/chalk/print_visitor.cr
index 6c10b8b..d21c13f 100644
--- a/src/chalk/print_visitor.cr
+++ b/src/chalk/print_visitor.cr
@@ -48,16 +48,16 @@ module Chalk
     end
 
     macro forward(text, type)
-            def visit(tree : {{type}})
-                print_indent
-                @stream << {{text}} << "\n"
-                @indent += 1
-            end
+      def visit(tree : {{type}})
+        print_indent
+        @stream << {{text}} << "\n"
+        @indent += 1
+      end
 
-            def finish(tree : {{type}})
-                @indent -= 1
-            end
-        end
+      def finish(tree : {{type}})
+        @indent -= 1
+      end
+    end
 
     forward("[call]", TreeCall)
     forward("[block]", TreeBlock)
@@ -67,4 +67,10 @@ module Chalk
     forward("[while]", TreeWhile)
     forward("[return]", TreeReturn)
   end
+
+  class Tree
+    def to_s(io)
+      accept(PrintVisitor.new io)
+    end
+  end
 end
diff --git a/src/chalk/table.cr b/src/chalk/table.cr
new file mode 100644
index 0000000..387b80a
--- /dev/null
+++ b/src/chalk/table.cr
@@ -0,0 +1,51 @@
+module Chalk
+  class Entry
+  end
+
+  class FunctionEntry < Entry
+    property function : TreeFunction
+    property addr : Int32
+
+    def initialize(@function : TreeFunction, @addr : Int32 = -1)
+    end
+
+    def to_s(io)
+      io << "[function]"
+    end
+  end
+
+  class VarEntry < Entry
+    property register : Int32
+
+    def initialize(@register : Int32)
+    end
+
+    def to_s(io)
+      io << "[variable] " << "(R" << @register.to_s(16) << ")"
+    end
+  end
+
+  class Table
+    property parent : Table?
+
+    def initialize(@parent : Table? = nil)
+      @data = {} of String => Entry
+    end
+
+    def []?(key) : Entry?
+      if entry = @data[key]?
+        return entry
+      end
+      return @parent.try &.[key]?
+    end
+
+    def []=(key, entry)
+      @data[key] = entry
+    end
+
+    def to_s(io)
+      @parent.try &.to_s(io)
+      io << @data.map { |k, v| k + ": " + v.to_s }.join("\n")
+    end
+  end
+end
diff --git a/src/chalk/tree.cr b/src/chalk/tree.cr
index d41f3aa..624c48e 100644
--- a/src/chalk/tree.cr
+++ b/src/chalk/tree.cr
@@ -1,5 +1,3 @@
-require "./print_visitor.cr"
-
 module Chalk
   class Visitor
     def visit(tree : Tree)
@@ -9,14 +7,20 @@ module Chalk
     end
   end
 
+  class Transformer
+    def transform(tree : Tree) : Tree
+      return tree
+    end
+  end
+
   class Tree
     def accept(v : Visitor)
       v.visit(self)
       v.finish(self)
     end
 
-    def to_s(io)
-        accept(PrintVisitor.new io)
+    def apply(t : Transformer)
+      return t.transform(self)
     end
   end
 
@@ -46,6 +50,13 @@ module Chalk
       @params.each &.accept(v)
       v.finish(self)
     end
+
+    def apply(t : Transformer)
+      @params.map! do |param|
+        param.apply(t)
+      end
+      return t.transform(self)
+    end
   end
 
   class TreeOp < Tree
@@ -62,9 +73,17 @@ module Chalk
       @right.accept(v)
       v.finish(self)
     end
+
+    def apply(t : Transformer)
+      @left = @left.apply(t)
+      @right = @right.apply(t)
+      return t.transform(self)
+    end
   end
 
   class TreeBlock < Tree
+    property children : Array(Tree)
+
     def initialize(@children : Array(Tree))
     end
 
@@ -73,6 +92,13 @@ module Chalk
       @children.each &.accept(v)
       v.finish(self)
     end
+
+    def apply(t : Transformer)
+      @children.map! do |child|
+        child.apply(t)
+      end
+      return t.transform(self)
+    end
   end
 
   class TreeFunction < Tree
@@ -88,6 +114,11 @@ module Chalk
       @block.accept(v)
       v.finish(self)
     end
+
+    def apply(t : Transformer)
+      @block = @block.apply(t)
+      return t.transform(self)
+    end
   end
 
   class TreeVar < Tree
@@ -102,6 +133,11 @@ module Chalk
       @expr.accept(v)
       v.finish(self)
     end
+
+    def apply(t : Transformer)
+      @expr = @expr.apply(t)
+      return t.transform(self)
+    end
   end
 
   class TreeAssign < Tree
@@ -116,6 +152,11 @@ module Chalk
       @expr.accept(v)
       v.finish(self)
     end
+
+    def apply(t : Transformer)
+      @expr = @expr.apply(t)
+      return t.transform(self)
+    end
   end
 
   class TreeIf < Tree
@@ -133,6 +174,13 @@ module Chalk
       @otherwise.try &.accept(v)
       v.finish(self)
     end
+
+    def apply(t : Transformer)
+      @condition = @condition.apply(t)
+      @block = @block.apply(t)
+      @otherwise = @otherwise.try &.apply(t)
+      return t.transform(self)
+    end
   end
 
   class TreeWhile < Tree
@@ -148,6 +196,12 @@ module Chalk
       @block.accept(v)
       v.finish(self)
     end
+
+    def apply(t : Transformer)
+      @condition = @condition.apply(t)
+      @block = @block.apply(t)
+      return t.transform(self)
+    end
   end
 
   class TreeReturn < Tree
@@ -161,5 +215,10 @@ module Chalk
       @rvalue.accept(v)
       v.finish(self)
     end
+
+    def apply(t : Transformer)
+      @rvalue = @rvalue.apply(t)
+      return t.transform(self)
+    end
   end
 end
diff --git a/src/chalk/ui.cr b/src/chalk/ui.cr
new file mode 100644
index 0000000..2bce834
--- /dev/null
+++ b/src/chalk/ui.cr
@@ -0,0 +1,51 @@
+module Chalk
+  enum OutputMode
+    Tree,
+    Intermediate,
+    Binary
+  end
+
+  class Config
+    property file : String
+    property mode : OutputMode
+
+    def initialize(@file : String = "",
+                   @mode = OutputMode::Tree)
+    end
+
+    def self.parse!
+      config = self.new
+      OptionParser.parse! do |parser|
+        parser.banner = "Usage: chalk [arguments]"
+        parser.on("-m", "--mode=MODE", "Set the mode of the compiler.") do |mode|
+          case mode.downcase
+          when "tree", "t"
+            config.mode = OutputMode::Tree
+          when "intermediate", "i"
+            config.mode = OutputMode::Intermediate
+          when "binary", "b"
+            config.mode = OutputMode::Binary
+          else
+            puts "Invalid mode type. Using default."
+          end
+        end
+        parser.on("-f", "--file=FILE", "Set the input file to compile.") do |file|
+          config.file = file
+        end
+        parser.on("-h", "--help", "Show this message.") { puts parser }
+      end
+      return config
+    end
+
+    def validate!
+      if file == ""
+        puts "No source file specified."
+        return false
+      elsif !File.exists? file
+        puts "Unable to open source file."
+        return false
+      end
+      return true
+    end
+  end
+end