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