stuff

from_scratch/compiler.rb

@@ -0,0 +1,57 @@
+#!/usr/bin/env ruby
+
+# lexer(tokeniser)->parser->code generator
+
+class Tokenizer
+  TOKEN_TYPES = [
+    [:def, /\bdef\b/],
+    [:end, /\bend\b/],
+    [:identifier, /\b[a-zA-Z]+\b/],
+    [:integer, /\b[0-9]+\b/],
+    [:oparen, /\(/],
+    [:cparen, /\)/],
+  ]
+
+  def initialize(code)
+    @code = code
+  end
+
+  def tokenize
+    tokens = []
+    until @code.empty?
+      token = tokenize_one
+      tokens << token
+      @code = @code.strip
+    end
+    return  tokens
+  end
+
+  def tokenize_one
+    TOKEN_TYPES.each do |type, re|
+      re = /\A(#{re})/
+      if @code =~ re
+        value = $1
+        @code = @code[value.length..-1]
+        return Token.new(type, value)
+      end
+    end
+  end
+end
+
+Token = Struct.new(:type, :value)
+
+# 11m30s
+class Parser
+  def initialize(tokens)
+    @tokens = tokens
+  end
+
+  def parse
+  end
+end
+
+
+tokens = Tokenizer.new(File.read("test.src")).tokenize
+puts tokens.map(&:inspect).join("\n")
+tree = Parser.new(tokens).parse
+p tree

from_scratch/test.src

@@ -0,0 +1,2 @@
+def f() 1 end
+