OS/2 Shareware BBS: 10 Tools/10-Tools.zip/ruby164.zip/rbemx164.zip/ruby/share/doc/racc-1.3.9/misc/racc2y

Text File | 2001-04-07 | 5KB | 268 lines

#!/usr/local/bin/ruby
#
# r2yacc  ---  racc to yacc converter
#
#   Copyright (c) 1999-2001 Minero Aoki <[e-mail]>
#
#   This program is feee software.
#   You can distribute/modify this program under the terms of
#   the GNU Lesser General Public License version 2 or later.
#

require 'getopts'
require 'racc/compiler'


class R

  Version = '1.1.0'


  def initialize
    @symboltable = Racc::SymbolTable.new( self )
    @ruletable   = Racc::RuleTable.new( self )
    @parser      = Racc::RaccParser.new( self )
  end

  attr :ruletable
  attr :symboltable
  attr :parser

  def debug()   false end
  def verbose() false end
  def d_parse() false end
  def d_token() false end
  def d_rule()  false end
  def d_state() false end


  ###
  ### parse
  ###

  def parse( str, fname )
    @fname = fname
    @parser.parse( str )
    @ruletable.init

    u = Racc::RaccParser.get_ucode( fname )
    @header, = u['header']
    @inner,  = u['inner']
    @footer, = u['footer']
  end


  ###
  ### output
  ###

  def output( f )
    rule = t = nil

    f.print <<SRC
/*

    generated from #{@fname} by racc2y version #{R::Version}

*/

SRC
    if $OPT_H and @header then
      f.puts '%{'
      f.puts '/*---- header ----*/'
      f.puts @header
      f.puts '%}'
      f.puts
    end

    output_defs f
    output_grammer f

    if $OPT_I and @inner then
      f.puts
      f.puts '/*---- inner ----*/'
      f.puts
      f.puts @inner
    end
    if $OPT_F and @footer then
      f.puts
      f.puts '/*---- footer ----*/'
      f.puts
      f.puts @footer
    end
  end

  def output_defs( f )
    output_token f
    f.puts
    prec = getprecs
    unless prec.empty? then
      output_prec f, prec
    end
  end

  def output_token( f )
    f.puts '/* tokens */'
    anc = @symboltable.anchor
    err = @symboltable.error
    total = 6
    f.print '%token'
    @symboltable.each do |t|
      next unless t.terminal?
      next if t.dummy?
      next if t == err
      next if t == anc

      unless String === t.value then
        if total > 60 then
          f.print "\n     "
          total = 0
        end
        total += f.write( " #{tok t}" )
      end
    end
    f.puts
  end

  def getprecs
    prec = []
    @symboltable.each do |t|
      next unless t.prec
      if a = prec[t.prec] then
        a.push t
      else
        prec[t.prec] = [t.assoc, t]
      end
    end

    prec
  end

  def output_prec( f, tab )
    f.puts '/* precedance table */'
    tab.each do |a|
      if a then
        f.printf '%%%-8s', a.shift.id2name.downcase
        a.each do |t|
          f.print ' ', tok(t)
        end
        f.puts
      end
    end
    f.puts
  end


  def output_grammer( f )
    f.puts '%%'

    targ   = nil
    indent = 10
    fmt    = "\n%-10s:"
    emb    = []

    @ruletable.each do |rule|
      if rule.target.dummy? then
        emb.push rule.action if rule.action
        next
      end

      if rule.target == targ then
        f.print ' ' * indent, '|'
      else
        targ = rule.target
        f.printf fmt, tok(targ)
      end
      rule.symbols.each do |t|
        if t.dummy? then   # target of dummy rule for embedded action
          f.puts
          output_act f,
                     emb.shift,
                     indent
          f.print ' ' * (indent + 1)
        else
          f.print ' ', tok(t)
        end
      end
      if rule.specified_prec then
        f.print ' %prec ', tok(rule.specified_prec)
      end
      f.puts
      if rule.action then
        output_act f, rule.action, indent
      end
    end

    f.puts "\n%%"
  end

  def output_act( f, str, indent )
    f.print ' ' * (indent + 4), "{\n"
    f.print ' ' * (indent + 6), str, "\n" unless $OPT_A
    f.print ' ' * (indent + 4), "}\n"
  end

  def tok( t )
    s = t.to_s
    s.gsub '"', "'"
  end

end   # class R


def usage( stat = 0 )
  if stat != 0 then
    $stderr.puts 'wrong option'
  end
  $stderr.print <<MSG

racc2y version #{R::Version}

usage:

    racc2y [-AHIF] [-o outfile] raccfile

    -o <file>  output file name  [y.<inputfile>]
    -A         did not output actions
    -H         output 'header'
    -I         output 'inner'
    -F         output 'footer'

MSG
  exit stat
end

unless getopts( 'AHIF', 'o:', 'version', 'help', 'copyright' ) then
  usage 1
end
if $OPT_version then
  $stderr.puts "racc2y version #{R::Version}"
  exit 0
end
if $OPT_help then
  usage 0
end
if $OPT_copyright then
  $stderr.puts "Copyright (c) 2000 Minero Aoki <[e-mail]>"
  exit 0
end
unless ARGV.size == 1 then
  usage 1
end


fname = ARGV[0]
outf = $OPT_o || 'y.' + fname
begin
  str = nil
  File.open( fname ) {|f| str = f.read }
rescue Errno::ENOENT
  $stderr.puts "#{File.basename $0}: no such file: #{fname}"
  exit 1
end
r = R.new
r.parse( str, fname )
File.open( outf, 'w' ) do |f|
  r.output f
end