txus/Readme.md

## Readme.md

      
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              Readme.md
            
          
    Bug with Rubinius + Racc gem (not stdlib)

Using the Racc gem instead of the stdlib version (both of them are version
1.4.9) breaks with the latest rubinius, only when racc/parser is required
twice.
$ rbx bug.rb

An exception occurred running bug.rb
    Missing or uninitialized constant: Racc::Parser::Racc_Runtime_Core_Id_C (NameError)

Backtrace:
                    Module(Class)#const_missing at kernel/common/module.rb:468
           Racc::Parser.__class_init__ (Parser) at /Users/txus/.rvm/gems/rbx-head@bug/gems/racc-1.4.9/lib/racc/parser.rb:41
                    Racc.__module_init__ (Racc) at /Users/txus/.rvm/gems/rbx-head@bug/gems/racc-1.4.9/lib/racc/parser.rb:31
                              Object#__script__ at /Users/txus/.rvm/gems/rbx-head@bug/gems/racc-1.4.9/lib/racc/parser.rb:25
                   Rubinius::CodeLoader.require at kernel/common/codeloader.rb:212
  Kernel(Object)#gem_original_require (require) at kernel/common/kernel.rb:631
                         Kernel(Object)#require at /Users/txus/.rvm/src/rbx-head/staging/lib/rubygems/custom_require.rb:36
                              Object#__script__ at lexer.rex.rb:7
                   Rubinius::CodeLoader.require at kernel/common/codeloader.rb:212
          Rubinius::CodeLoader.require_relative at kernel/common/codeloader19.rb:28
                Kernel(Object)#require_relative at kernel/common/kernel19.rb:176
                              Object#__script__ at parser.tab.rb:12
                   Rubinius::CodeLoader.require at kernel/common/codeloader.rb:212
          Rubinius::CodeLoader.require_relative at kernel/common/codeloader19.rb:28
                Kernel(Object)#require_relative at kernel/common/kernel19.rb:176
                              Object#__script__ at bug.rb:1
               Rubinius::CodeLoader#load_script at kernel/delta/codeloader.rb:68
               Rubinius::CodeLoader.load_script at kernel/delta/codeloader.rb:110
                        Rubinius::Loader#script at kernel/loader.rb:626
                          Rubinius::Loader#main at kernel/loader.rb:829

This is probably related to the double loading problem pointed out in this
issue.
The strange thing is that it works with the Stdlib version, but not with the
gem.
(A workaround to avoid failure is removing the require 'racc/parser' line on
parser.tab.rb., thus avoid double loading).

  
## bug.rb
require_relative 'parser.tab'

## lexer.rex
#
# lexer.rex
#
# Lexer
#
class Parser

macro
  BLANK         [\ ]

rule
  .             { [text, text] }

inner
  def run(code)
    scan_setup(code.strip)
    tokens = []
    while token = next_token
      tokens << token
    end
    tokens
  end

end

## lexer.rex.rb
#--
# DO NOT MODIFY!!!!
# This file is automatically generated by rex 1.0.5
# from lexical definition file "lexer.rex".
#++

require 'racc/parser'
#
# lexer.rex
#
# Lexer
#
class Parser < Racc::Parser
  require 'strscan'

  class ScanError < StandardError ; end

  attr_reader   :lineno
  attr_reader   :filename
  attr_accessor :state

  def scan_setup(str)
    @ss = StringScanner.new(str)
    @lineno =  1
    @state  = nil
  end

  def action
    yield
  end

  def scan_str(str)
    scan_setup(str)
    do_parse
  end
  alias :scan :scan_str

  def load_file( filename )
    @filename = filename
    open(filename, "r") do |f|
      scan_setup(f.read)
    end
  end

  def scan_file( filename )
    load_file(filename)
    do_parse
  end


  def next_token
    return if @ss.eos?

    # skips empty actions
    until token = _next_token or @ss.eos?; end
    token
  end

  def _next_token
    text = @ss.peek(1)
    @lineno  +=  1  if text == "\n"
    token = case @state
    when nil
      case
      when (text = @ss.scan(/./))
         action { [text, text] }

      else
        text = @ss.string[@ss.pos .. -1]
        raise  ScanError, "can not match: '" + text + "'"
      end  # if

    else
      raise  ScanError, "undefined state: '" + state.to_s + "'"
    end  # case state
    token
  end  # def _next_token

  def run(code)
    scan_setup(code.strip)
    tokens = []
    while token = next_token
      tokens << token
    end
    tokens
  end
end # class

## parser.tab.rb
#
# DO NOT MODIFY!!!!
# This file is automatically generated by Racc 1.4.7
# from Racc grammer file "".
#

require 'racc/parser.rb'

#
# generated by racc
#
require_relative 'lexer.rex'

class Parser < Racc::Parser

module_eval(<<'...end parser.y/module_eval...', 'parser.y', 22)

def filename
  @filename
end

def on_error(t, val, vstack)
  raise ParseError, sprintf("\nparse error on value %s (%s) #{@filename}:#{@line}",
      val.inspect, token_to_str(t) || '?')
end

...end parser.y/module_eval...
##### State transition tables begin ###

racc_action_table = [
     2,     3 ]

racc_action_check = [
     1,     2 ]

racc_action_pointer = [
   nil,     0,     1,   nil ]

racc_action_default = [
    -1,    -2,    -2,     4 ]

racc_goto_table = [
     1 ]

racc_goto_check = [
     1 ]

racc_goto_pointer = [
   nil,     0 ]

racc_goto_default = [
   nil,   nil ]

racc_reduce_table = [
  0, 0, :racc_error,
  0, 3, :_reduce_1 ]

racc_reduce_n = 2

racc_shift_n = 4

racc_token_table = {
  false => 0,
  :error => 1 }

racc_nt_base = 2

racc_use_result_var = true

Racc_arg = [
  racc_action_table,
  racc_action_check,
  racc_action_default,
  racc_action_pointer,
  racc_goto_table,
  racc_goto_check,
  racc_goto_default,
  racc_goto_pointer,
  racc_nt_base,
  racc_reduce_table,
  racc_token_table,
  racc_shift_n,
  racc_reduce_n,
  racc_use_result_var ]

Racc_token_to_s_table = [
  "$end",
  "error",
  "$start",
  "Root" ]

Racc_debug_parser = false

##### State transition tables end #####

# reduce 0 omitted

module_eval(<<'.,.,', 'parser.y', 11)
  def _reduce_1(val, _values, result)
     result = []
    result
  end
.,.,

def _reduce_none(val, _values, result)
  val[0]
end

end   # class Parser


## parser.y
#
# Noscript grammar.
#

class Parser

# Declare tokens produced by the lexer

rule
  # The trunk of the AST.
  Root:
    /* nothing */     { result = [] }
  ;

---- header ----
#
# generated by racc
#
require_relative 'lexer.rex'

---- inner ----

def filename
  @filename
end

def on_error(t, val, vstack)
  raise ParseError, sprintf("\nparse error on value %s (%s) #{@filename}:#{@line}",
      val.inspect, token_to_str(t) || '?')
end

---- footer ----
	#
	# lexer.rex
	#
	# Lexer
	#
	class Parser

	macro
	BLANK [\ ]

	rule
	. { [text, text] }

	inner
	def run(code)
	scan_setup(code.strip)
	tokens = []
	while token = next_token
	tokens << token
	end
	tokens
	end

	end
	#--
	# DO NOT MODIFY!!!!
	# This file is automatically generated by rex 1.0.5
	# from lexical definition file "lexer.rex".
	#++

	require 'racc/parser'
	#
	# lexer.rex
	#
	# Lexer
	#
	class Parser < Racc::Parser
	require 'strscan'

	class ScanError < StandardError ; end

	attr_reader :lineno
	attr_reader :filename
	attr_accessor :state

	def scan_setup(str)
	@ss = StringScanner.new(str)
	@lineno = 1
	@state = nil
	end

	def action
	yield
	end

	def scan_str(str)
	scan_setup(str)
	do_parse
	end
	alias :scan :scan_str

	def load_file( filename )
	@filename = filename
	open(filename, "r") do \|f\|
	scan_setup(f.read)
	end
	end

	def scan_file( filename )
	load_file(filename)
	do_parse
	end


	def next_token
	return if @ss.eos?

	# skips empty actions
	until token = _next_token or @ss.eos?; end
	token
	end

	def _next_token
	text = @ss.peek(1)
	@lineno += 1 if text == "\n"
	token = case @state
	when nil
	case
	when (text = @ss.scan(/./))
	action { [text, text] }

	else
	text = @ss.string[@ss.pos .. -1]
	raise ScanError, "can not match: '" + text + "'"
	end # if

	else
	raise ScanError, "undefined state: '" + state.to_s + "'"
	end # case state
	token
	end # def _next_token

	def run(code)
	scan_setup(code.strip)
	tokens = []
	while token = next_token
	tokens << token
	end
	tokens
	end
	end # class
	#
	# DO NOT MODIFY!!!!
	# This file is automatically generated by Racc 1.4.7
	# from Racc grammer file "".
	#

	require 'racc/parser.rb'

	#
	# generated by racc
	#
	require_relative 'lexer.rex'

	class Parser < Racc::Parser

	module_eval(<<'...end parser.y/module_eval...', 'parser.y', 22)

	def filename
	@filename
	end

	def on_error(t, val, vstack)
	raise ParseError, sprintf("\nparse error on value %s (%s) #{@filename}:#{@line}",
	val.inspect, token_to_str(t) \|\| '?')
	end

	...end parser.y/module_eval...
	##### State transition tables begin ###

	racc_action_table = [
	2, 3 ]

	racc_action_check = [
	1, 2 ]

	racc_action_pointer = [
	nil, 0, 1, nil ]

	racc_action_default = [
	-1, -2, -2, 4 ]

	racc_goto_table = [
	1 ]

	racc_goto_check = [
	1 ]

	racc_goto_pointer = [
	nil, 0 ]

	racc_goto_default = [
	nil, nil ]

	racc_reduce_table = [
	0, 0, :racc_error,
	0, 3, :_reduce_1 ]

	racc_reduce_n = 2

	racc_shift_n = 4

	racc_token_table = {
	false => 0,
	:error => 1 }

	racc_nt_base = 2

	racc_use_result_var = true

	Racc_arg = [
	racc_action_table,
	racc_action_check,
	racc_action_default,
	racc_action_pointer,
	racc_goto_table,
	racc_goto_check,
	racc_goto_default,
	racc_goto_pointer,
	racc_nt_base,
	racc_reduce_table,
	racc_token_table,
	racc_shift_n,
	racc_reduce_n,
	racc_use_result_var ]

	Racc_token_to_s_table = [
	"$end",
	"error",
	"$start",
	"Root" ]

	Racc_debug_parser = false

	##### State transition tables end #####

	# reduce 0 omitted

	module_eval(<<'.,.,', 'parser.y', 11)
	def _reduce_1(val, _values, result)
	result = []
	result
	end
	.,.,

	def _reduce_none(val, _values, result)
	val[0]
	end

	end # class Parser
	#
	# Noscript grammar.
	#

	class Parser

	# Declare tokens produced by the lexer

	rule
	# The trunk of the AST.
	Root:
	/* nothing */ { result = [] }
	;

	---- header ----
	#
	# generated by racc
	#
	require_relative 'lexer.rex'

	---- inner ----

	def filename
	@filename
	end

	def on_error(t, val, vstack)
	raise ParseError, sprintf("\nparse error on value %s (%s) #{@filename}:#{@line}",
	val.inspect, token_to_str(t) \|\| '?')
	end

	---- footer ----