dankcode compiler

#!/usr/bin/env ruby

class DankCode
  def initialize(path)
    @code = File.readlines(path).map(&:chomp)
  end

  def parse_expr(expr)
    expr.gsub(/\bisn't\b/, "!=").gsub(/\bis\b/, "==").gsub(/:(\S+)/) { %Q["#{$1}"] }
  end

  def transcode_line(line)
    indent = line[/\A\t*/]
    line = line.sub(/\A\t*/, "")
    return nil unless line =~ /\S+/
    ruby = case line
    when /\A>tfw (\w+)\z/
      "return #{$1}"
    when /\A>mfw (\w+)\z/
      "puts #{$1}"
    when /\A>implying (.*)\z/
      "if #{parse_expr($1)}"
    when /\A>be (\w+) like (.*)\z/
      "#{$1} = #{parse_expr($2)}"
    when ">done implying"
      "end"
    when ">or not"
      "else"
    when /\A>wew (\w+\(.*?\))\z/
      "wew = #{$1}"
    when />wewlad (.*)/
      "def #{$1}"
    when ">be me"
      "def main"
    when ">thank mr skeltal"
      "exit"
    else
      warn "Can't parse #{line}"
      ""
    end
    [indent.gsub("\t", "  "), ruby]
  end

  def run!
    ruby_lines = @code.map do |line| transcode_line(line) end.compact
    ruby = []
    ruby_lines.each do |i,c|
      ruby << "end" if c =~ /\Adef/
      ruby << "#{i}#{c}"
    end
    ruby << "end"
    ruby << "main"
    puts ruby[1..-1]
  end
end

path = ARGV[0]

DankCode.new(path).run!