Class: Matcher

Inherits:
Object show all
Defined in:
lib/ytljit/matcher.rb

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Matcher

Returns a new instance of Matcher.



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# File 'lib/ytljit/matcher.rb', line 62

def initialize
  @cache = {}
  @code = nil
  @pattern = []
end

Instance Method Details

#code_gen(info) ⇒ Object 



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# File 'lib/ytljit/matcher.rb', line 162

def code_gen(info)
  ct = {}
  info.each do |carr, val|
    cursor = ct
    carr.each do |cele|
      cursor[cele] ||= {}
      cursor = cursor[cele]
    end
    cursor[nil] = val
  end

  code = <<-EOS
  org_self = self
  ObjectSpace._id2ref(#{self.object_id}).instance_eval do 
    #{cond_gen(ct, 0)} 
  end
EOS
  RubyVM::InstructionSequence.compile(code)
end

#compile ⇒ Object 



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# File 'lib/ytljit/matcher.rb', line 82

def compile
  info = {}
  @pattern.each do |pat|
    env = {}
    cond = compile_aux(pat[0], [], env, [])[0]
    info[cond] = [env, pat[1]]
  end
  @code = code_gen(info)
end

#compile_aux(pat, stack, env, cond) ⇒ Object 



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# File 'lib/ytljit/matcher.rb', line 92

def compile_aux(pat, stack, env, cond)
  status = :normal
  case pat
  when Array
    if pat[0].is_a?(Class) then
      cond.push "(#{get_patref(stack)}.is_a?(#{pat[0]}))"
      env[pat[1]] = "#{get_patref(stack)}"
    else
      cond.push "(#{get_patref(stack)}.is_a?(Array))"
      stack.push 0
      pat.each_with_index do |ele, i|
        stack[-1] = i
        cond, st = compile_aux(ele, stack, env, cond)
        if st == :return then
          stack.pop
          return [cond, status]
        end
      end
      stack[-1] = pat.size
      cond.push "(#{get_patref(stack)} == nil)"
      stack.pop
    end
    
  when Symbol
    patstr = pat.to_s
    if patstr[0] == '_' then
      npat = patstr[1..-1].to_sym
      if env[npat] then
        cond.push "#{get_patref_rest(stack)} == #{env[npat]}"
      else
        env[npat] = get_patref_rest(stack)
      end
      status = :return
    else
      if env[pat] then
        cond.push "(#{get_patref(stack)}.is_a?(Symbol) or #{get_patref(stack)} == #{env[pat]})"
      else
        env[pat] = get_patref(stack).to_s
      end
    end

  when QuotedObj
    cond.push "(#{get_patref(stack)} == #{pat.obj.inspect})"

  else
    cond.push "(#{get_patref(stack)} == #{pat})"
  end

  return [cond, status]
end

#cond_gen(tr, level) ⇒ Object 



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# File 'lib/ytljit/matcher.rb', line 182

def cond_gen(tr, level)
  code = ""
  tr.each do |cond, nxt|
    if cond then
      code << "if #{cond} then \n"
      code << cond_gen(nxt, level + 1)
      code << "end\n"
    end
  end
  if tr[nil] then
    code << "#{exec_gen(tr[nil])} \n"
  end
  code
end

#exec_gen(para) ⇒ Object 



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# File 'lib/ytljit/matcher.rb', line 197

def exec_gen(para)
  hash = "{"
  para[0].each do |key, value|
    hash << ":#{key} => #{value},"
  end
  hash << "}"
  
  proc = para[1]
  "break ObjectSpace._id2ref(#{proc.object_id}).call(#{hash})"
end

#get_patref(stack) ⇒ Object 



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# File 'lib/ytljit/matcher.rb', line 143

def get_patref(stack)
  code = "@src"
  stack.each do |n|
    code += "[#{n}]"
  end
  code
end

#get_patref_rest(stack) ⇒ Object 



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# File 'lib/ytljit/matcher.rb', line 151

def get_patref_rest(stack)
  code = "@src"
  top = stack.pop
  stack.each do |n|
    code += "[#{n}]"
  end
  code += "[#{top}.. -1]"
  stack.push top
  code
end

#match(src) ⇒ Object 



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# File 'lib/ytljit/matcher.rb', line 68

def match(src)
  unless @code
    compile
  end
  @src = src
  @code.eval
end

#pattern(pat, &block) ⇒ Object 



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# File 'lib/ytljit/matcher.rb', line 76

def pattern(pat, &block)
  unless @code
    @pattern.push [pat, block]
  end
end