This commit was manufactured by cvs2svn to create branch 'RUBY'.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/RUBY@9 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 962 insertions, 0 deletions

diff --git a/sample/rbc.rb b/sample/rbc.rb
new file mode 100644
index 0000000000..88a5b2d069
--- /dev/null
+++ b/sample/rbc.rb
@@ -0,0 +1,962 @@
+#!/usr/local/bin/ruby
+#
+#   rbc.rb - 
+#   	$Release Version: 0.6 $
+#   	$Revision: 1.2 $
+#   	$Date: 1997/11/27 13:46:06 $
+#   	by Keiju ISHITSUKA(Nippon Rational Inc.)
+#
+# --
+# Usage:
+#
+#   rbc.rb [options] file_name opts
+#   options:
+#	-d		    デバッグモード(利用しない方が良いでしょう)
+#	-m		    bcモード(分数, 行列の計算ができます)
+#	-r load-module	    ruby -r と同じ
+#	--inspect	    結果出力にinspectを用いる(bcモード以外はデ
+#			    フォルト). 
+#	--noinspect	    結果出力にinspectを用いない.
+#	--noreadline	    readlineライブラリを利用しない(デフォルト
+#			    ではreadlineライブラリを利用しようとする).
+#
+# 追加 private method:
+#   exit, quit		    終了する.
+#   inspect(sw = nil)	    インスペクトモードのトグル
+#   trace_load(sw = nil)    load/require時にrbcのfile読み込み機能を用
+#			    いるモードのスイッチ(デフォルトはトレース
+#			    モード)
+#
+require "e2mmap.rb"
+
+$stdout.sync = TRUE
+
+module BC_APPLICATION__
+  RCS_ID='-$Header: /home/keiju/var/src/var.lib/ruby/ruby/RCS/rbc.rb,v 1.2 1997/11/27 13:46:06 keiju Exp keiju $-'
+  
+  extend Exception2MessageMapper
+  def_exception :UnrecognizedSwitch, "Unrecognized switch: %s"
+  
+  $DEBUG = FALSE
+  $INSPECT = nil
+  
+  CONFIG = {}
+  CONFIG[0] = $0
+  CONFIG[:USE_READLINE] = TRUE
+  CONFIG[:LOAD_MODULES] = []
+  CONFIG[:INSPECT] = nil
+  CONFIG[:TRACE_LOAD] = TRUE
+
+  while opt = ARGV.shift
+    case opt
+    when "-d"
+      $DEBUG = TRUE
+    when "-m"
+      CONFIG[:INSPECT] = FALSE if CONFIG[:INSPECT].nil?
+      require "mathn.rb"
+      include Math
+    when "-r"
+      opt = ARGV.shift
+      CONFIG[:LOAD_MODULES].push opt if opt
+    when "--inspect"
+      CONFIG[:INSPECT] = TRUE
+    when "--noinspect"
+      CONFIG[:INSPECT] = FALSE
+    when "--noreadline"
+      CONFIG[:USE_READLINE] = FALSE
+    when /^-/
+      #	  print UnrecognizedSwitch.inspect, "\n"
+      BC.fail UnrecognizedSwitch, opt
+    else
+      CONFIG[:USE_READLINE] = FALSE
+      $0 = opt
+      break
+    end
+  end
+  CONFIG[:INSPECT] = TRUE if CONFIG[:INSPECT].nil?
+
+  PROMPTi = "rbc%d> "
+  PROMPTs = "rbc%d%s "
+  PROMPTe = "rbc%d* "
+  
+  class BC
+    def initialize
+      lex_init
+    end
+    
+    def eval_input(io, cont, bind)
+      line = ''
+      @io = io
+      @ltype = nil
+      @quoted = nil
+      @indent = 0
+      @lex_state = EXPR_BEG
+      
+      @io.prompt = format(PROMPTi, @indent)
+
+      loop do
+	@continue = FALSE
+	l = @io.gets
+
+	unless l
+	  break if line == ''
+	else
+	  line = line + l
+	  
+	  lex(l) if l != "\n"
+	  print @quoted.inspect, "\n" if $DEBUG
+	  if @ltype
+	    @io.prompt = format(PROMPTs, @indent, @ltype)
+	    next
+	  elsif @continue
+	    @io.prompt = format(PROMPTe, @indent)
+	    next
+	  elsif @indent > 0
+	    @io.prompt = format(PROMPTi, @indent)
+	    next
+	  end
+	end
+	
+	if line != "\n"
+	  begin
+	    if CONFIG[:INSPECT]
+	      print (cont._=eval(line, bind)).inspect, "\n"
+	    else
+	      print (cont._=eval(line, bind)), "\n"
+	    end
+	  rescue
+	    #	$! = 'exception raised' unless $!
+	    #	print "ERR: ", $!, "\n"
+	    $! = RuntimeError.new("exception raised") unless $!
+	    print $!.type, ": ", $!, "\n"
+	  end
+	end
+	break if not l
+	line = ''
+	indent = 0
+	@io.prompt = format(PROMPTi, indent)
+      end
+      print "\n"
+    end
+    
+    EXPR_BEG = :EXPR_BEG
+    EXPR_MID = :EXPR_MID
+    EXPR_END = :EXPR_END
+    EXPR_ARG = :EXPR_ARG
+    EXPR_FNAME = :EXPR_FNAME
+
+    CLAUSE_STATE_TRANS = {
+      "alias"	=>  EXPR_FNAME,
+      "and"	=>  EXPR_BEG,
+      "begin"	=>  EXPR_BEG,
+      "case"	=>  EXPR_BEG,
+      "class"	=>  EXPR_BEG,
+      "def"	=>  EXPR_FNAME,
+      "defined?"	=>  EXPR_END,
+      "do"	=>  EXPR_BEG,
+      "else"	=>  EXPR_BEG,
+      "elsif"	=>  EXPR_BEG,
+      "end"	=>  EXPR_END,
+      "ensure"	=>  EXPR_BEG,
+      "for"	=>  EXPR_BEG,
+      "if"	=>  EXPR_BEG,
+      "in"	=>  EXPR_BEG,
+      "module"	=>  EXPR_BEG,
+      "nil"	=>  EXPR_END,
+      "not"	=>  EXPR_BEG,
+      "or"	=>  EXPR_BEG,
+      "rescue"	=>  EXPR_MID,
+      "return"	=>  EXPR_MID,
+      "self"	=>  EXPR_END,
+      "super"	=>  EXPR_END,
+      "then"	=>  EXPR_BEG,
+      "undef"	=>  EXPR_FNAME,
+      "unless"	=>  EXPR_BEG,
+      "until"	=>  EXPR_BEG,
+      "when"	=>  EXPR_BEG,
+      "while"	=>  EXPR_BEG,
+      "yield"	=>  EXPR_END
+    }
+    
+    ENINDENT_CLAUSE = [
+      "case", "class", "def", "do", "for", "if",
+      "module", "unless", "until", "while", "begin" #, "when"
+    ]
+    DEINDENT_CLAUSE = ["end"]
+
+    PARCENT_LTYPE = {
+      "q" => "\'",
+      "Q" => "\"",
+      "x" => "\`",
+      "r" => "\/"
+    }
+    
+    PARCENT_PAREN = {
+      "{" => "}",
+      "[" => "]",
+      "<" => ">",
+      "(" => ")"
+    }
+    
+    def lex_init()
+      @OP = Trie.new
+      @OP.def_rules("\0", "\004", "\032"){}
+      @OP.def_rules(" ", "\t", "\f", "\r", "\13") do
+	@space_seen = TRUE
+	next
+      end
+      @OP.def_rule("#") do
+	|op, rests|
+	@ltype = "#"
+	identify_comment(rests)
+      end
+      @OP.def_rule("\n") do
+	print "\\n\n" if $DEBUG
+	if @lex_state == EXPR_BEG || @lex_state == EXPR_FNAME
+	  @continue = TRUE
+	else
+	  @lex_state = EXPR_BEG
+	end
+      end
+      @OP.def_rules("*", "*=", "**=", "**") {@lex_state = EXPR_BEG}
+      @OP.def_rules("!", "!=", "!~") {@lex_state = EXPR_BEG}
+      @OP.def_rules("=", "==", "===", "=~", "=>") {@lex_state = EXPR_BEG}
+      @OP.def_rules("<", "<=", "<=>", "<<", "<=") {@lex_state = EXPR_BEG}
+      @OP.def_rules(">", ">=", ">>", ">=") {@lex_state = EXPR_BEG}
+      @OP.def_rules("'", '"') do
+	|op, rests|
+	@ltype = op
+	@quoted = op
+	identify_string(rests)
+      end
+      @OP.def_rules("`") do
+	|op, rests|
+	if @lex_state != EXPR_FNAME
+	  @ltype = op
+	  @quoted = op
+	  identify_string(rests)
+	end
+      end
+      @OP.def_rules('?') do
+	|op, rests|
+	@lex_state = EXPR_END
+	identify_question(rests)
+      end
+      @OP.def_rules("&", "&&", "&=", "|", "||", "|=") do
+	@lex_state = EXPR_BEG
+      end
+      @OP.def_rule("+@", proc{@lex_state == EXPR_FNAME}) {}
+      @OP.def_rule("-@", proc{@lex_state == EXPR_FNAME}) {}
+      @OP.def_rules("+=", "-=") {@lex_state = EXPR_BEG}
+      @OP.def_rules("+", "-") do
+	|op, rests|
+	if @lex_state == EXPR_ARG
+	  if @space_seen and rests[0] =~ /[0-9]/
+	    identify_number(rests)
+	  else
+	    @lex_state = EXPR_BEG
+	  end
+	elsif @lex_state != EXPR_END and rests[0] =~ /[0-9]/
+	  identify_number(rests)
+	else
+	  @lex_state = EXPR_BEG
+	end
+      end
+      @OP.def_rule(".") do
+	|op, rests|
+	@lex_state = EXPR_BEG
+	if rests[0] =~ /[0-9]/
+	  rests.unshift op
+	  identify_number(rests)
+	end
+      end
+      @OP.def_rules("..", "...") {@lex_state = EXPR_BEG}
+      
+      lex_int2
+    end
+    
+    def lex_int2
+      @OP.def_rules("]", "}", ")") do
+	@lex_state = EXPR_END
+	@indent -= 1
+      end
+      @OP.def_rule(":") {}
+      @OP.def_rule("::") {@lex_state = EXPR_BEG}
+      @OP.def_rule("/") do
+	|op, rests|
+	if @lex_state == EXPR_BEG || @lex_state == EXPR_MID
+	  @ltype = op
+	  @quoted = op
+	  identify_string(rests)
+	elsif rests[0] == '='
+	  rests.shift
+	  @lex_state = EXPR_BEG
+	elsif @lex_state == EXPR_ARG and @space_seen and rests[0] =~ /\s/
+	  @ltype = op
+	  @quoted = op
+	  identify_string(rests)
+	else 
+	  @lex_state = EXPR_BEG
+	end
+      end
+      @OP.def_rules("^", "^=") {@lex_state = EXPR_BEG}
+      @OP.def_rules(",", ";") {@lex_state = EXPR_BEG}
+      @OP.def_rule("~") {@lex_state = EXPR_BEG}
+      @OP.def_rule("~@", proc{@lex_state = EXPR_FNAME}) {}
+      @OP.def_rule("(") do
+	@lex_state = EXPR_BEG
+	@indent += 1
+      end
+      @OP.def_rule("[]", proc{@lex_state == EXPR_FNAME}) {}
+      @OP.def_rule("[]=", proc{@lex_state == EXPR_FNAME}) {}
+      @OP.def_rule("[") do
+	@indent += 1
+	if @lex_state != EXPR_FNAME
+	  @lex_state = EXPR_BEG
+	end
+      end
+      @OP.def_rule("{") do
+	@lex_state = EXPR_BEG
+	@indent += 1
+      end
+      @OP.def_rule('\\') {|op, rests| identify_escape(rests)} #')
+      @OP.def_rule('%') do
+	|op, rests|
+	if @lex_state == EXPR_BEG || @lex_state == EXPR_MID
+	  identify_quotation(rests)
+	elsif rests[0] == '='
+	  rests.shift
+	elsif @lex_state == EXPR_ARG and @space_seen and rests[0] =~ /\s/
+	  identify_quotation(rests)
+	else
+	  @lex_state = EXPR_BEG
+	end
+      end
+      @OP.def_rule('$') do
+	|op, rests|
+	identify_gvar(rests)
+      end
+      @OP.def_rule('@') do
+	|op, rests|
+	if rests[0] =~ /[\w_]/
+	  rests.unshift op
+	  identify_identifier(rests)
+	end
+      end
+      @OP.def_rule("") do
+	|op, rests|
+	printf "match: start %s: %s", op, rests.inspect if $DEBUG
+	if rests[0] =~ /[0-9]/
+	  identify_number(rests)
+	elsif rests[0] =~ /[\w_]/
+	  identify_identifier(rests)
+	end
+	printf "match: end %s: %s", op, rests.inspect if $DEBUG
+      end
+    end
+    
+    def lex(l)
+      chrs = l.split(//)
+      tokens = []
+      
+      case @ltype
+      when "'", '"', '`', '/'
+	identify_string(chrs)
+	return if chrs.empty?
+      when "#"
+	identify_comment(chrs)
+	return
+      when "="
+	if l =~ /^=end/
+	  $ltype = nil
+	  return
+	end
+      else
+	if l =~ /^=begin/
+	  $ltype = "="
+	  return
+	end
+      end
+      
+      until chrs.empty?
+	@space_seen = FALSE
+	printf "perse: %s\n", chrs.join("") if $DEBUG
+	@OP.match(chrs)
+	printf "lex_state: %s continue: %s\n", @lex_state.id2name, @continue if $DEBUG
+      end
+    end
+    
+    def identify_gvar(chrs)
+      @lex_state = EXPR_END
+      
+      ch = chrs.shift
+      case ch
+      when /[_~*$?!@/\\;,.=:<>"]/   #"
+	return
+	
+      when "-"
+	ch = chrs.shift
+	return
+	
+      when "&", "`", "'", "+"
+	return
+	
+      when /[1-9]/
+	chrs.unshift ch
+	v = "$"
+	while (ch = chrs.shift) =~ /[0-9]/
+	end
+	chrs.unshift ch
+	return
+	
+      when /\w/
+	chrs.unshift ch
+	chrs.unshift "$"
+	identify_identifier(chrs)
+	return
+	
+      else 
+	chrs.unshift ch
+	return
+      end
+    end
+    
+    def identify_identifier(chrs)
+      token = ""
+      token.concat chrs.shift if chrs[0] =~ /[$@]/
+      while (ch = chrs.shift) =~ /\w|_/
+	print ":", ch, ":" if $DEBUG
+	token.concat ch
+      end
+      chrs.unshift ch
+      
+      if ch == "!" or ch == "?"
+	chrs.shift
+	token.concat ch
+      end
+      # fix token
+      
+      if token =~ /^[$@]/
+	@lex_state = EXPR_END
+	return
+      end
+      
+      print token, "\n" if $DEBUG
+      if state = CLAUSE_STATE_TRANS[token]
+	if @lex_state != EXPR_BEG and token =~ /^(if|unless|while|until)/
+	  # 修飾子
+	else
+	  if ENINDENT_CLAUSE.include?(token)
+	    @indent += 1
+	  elsif DEINDENT_CLAUSE.include?(token)
+	    @indent -= 1
+	  end
+	end
+	@lex_state = state
+	return
+      end
+      if @lex_state == EXPR_FNAME
+	@lex_state = EXPR_END
+	if chrs[0] == '='
+	  chrs.shift
+	end
+      elsif @lex_state == EXPR_BEG
+	@lex_state = EXPR_ARG
+      else
+	@lex_state = EXPR_END
+      end
+    end
+    
+    def identify_quotation(chrs)
+      ch = chrs.shift
+      if lt = PARCENT_LTYPE[ch]
+	ch = chrs.shift
+      else
+	lt = "\""
+      end
+      if ch !~ /\W/
+	chrs.unshift ch
+	next
+      end
+      @ltype = lt
+      unless @quoted = PARCENT_PAREN[ch]
+	@quoted = ch
+      end
+      identify_string(chrs)
+    end
+
+    def identify_number(chrs)
+      @lex_state = EXPR_END
+      
+      ch = chrs.shift
+      case ch
+      when /0/
+	if (ch = chrs[0]) == "x"
+	  chrs.shift
+	  match = /[0-9a-f_]/
+	else
+	  match = /[0-7_]/
+	end
+	while ch = chrs.shift
+	  if ch !~ match
+	    chrs.unshift ch
+	    break
+	  end
+	end
+	return
+      end
+      
+      while ch = chrs.shift
+	case ch
+	when /[0-9]/
+	when "e", "E"
+	  #	type = FLOAT
+	  unless (ch = chrs.shift) == "+" or ch == "-"
+	    chrs.unshift ch
+	  end
+	when "."
+	  #	type = FLOAT
+	when "_"
+	else
+	  chrs.unshift ch
+	  return
+	end
+      end
+    end
+    
+    def identify_question(chrs)
+      @lex_state = EXPR_END
+      
+      if chrs.shift == "\\" #"
+	identify_escape(chrs)
+      end
+    end
+    
+    def identify_string(chrs)
+      while ch = chrs.shift
+	if @quoted == ch
+	  if @ltype == "/"
+	    if chrs[0] =~ /i|o|n|e|s/
+	      chrs.shift
+	    end
+	  end
+	  @ltype = nil
+	  @quoted = nil
+	  @lex_state = EXPR_END
+	  break
+	elsif ch == '\\' #'
+	  identify_escape(chrs)
+	end
+      end
+    end
+    
+    def identify_comment(chrs)
+      while ch = chrs.shift
+	if ch == "\\" #"
+	  identify_escape(chrs)
+	end
+	if ch == "\n"
+	  @ltype = nil
+	  chrs.unshift ch
+	  break
+	end
+      end
+    end
+    
+    def identify_escape(chrs)
+      ch = chrs.shift
+      case ch
+      when "\n", "\r", "\f"
+	@continue = TRUE
+      when "\\", "n", "t", "r", "f", "v", "a", "e", "b" #"
+      when /[0-7]/
+	chrs.unshift ch
+	3.times do
+	  ch = chrs.shift
+	  case ch
+	  when /[0-7]/
+	  when nil
+	    break
+	  else
+	    chrs.unshift ch
+	    break
+	  end
+	end
+      when "x"
+	2.times do
+	  ch = chrs.shift
+	  case ch
+	  when /[0-9a-fA-F]/
+	  when nil
+	    break
+	  else
+	    chrs.unshift ch
+	    break
+	  end
+	end
+      when "M"
+	if (ch = chrs.shift) != '-'
+	  chrs.unshift ch
+	elsif (ch = chrs.shift) == "\\" #"
+	  identify_escape(chrs)
+	end
+	return
+      when "C", "c", "^"
+	if ch == "C" and (ch = chrs.shift) != "-"
+	  chrs.unshift ch
+	elsif (ch = chrs.shift) == "\\" #"
+	  identify_escape(chrs)
+	end
+	return
+      end
+    end
+  end
+  
+  class Trie
+    extend Exception2MessageMapper
+    def_exception :ErrNodeNothing, "node nothing"
+    def_exception :ErrNodeAlreadyExists, "node already exists"
+
+    class Node
+      # postprocがなければ抽象ノード, nilじゃなければ具象ノード
+      def initialize(preproc = nil, postproc = nil)
+	@Tree = {}
+	@preproc = preproc
+	@postproc = postproc
+      end
+      
+      def preproc(p)
+	@preproc = p
+      end
+      
+      def postproc(p)
+	@postproc = p
+      end
+      
+      def search(chrs, opt = nil)
+	return self if chrs.empty?
+	ch = chrs.shift
+	if node = @Tree[ch]
+	  node.search(chrs, opt)
+	else
+	  if opt
+	    chrs.unshift ch
+	    self.create_subnode(chrs)
+	  else
+	    Trie.fail ErrNodeNothing
+	  end
+	end
+      end
+      
+      def create_subnode(chrs, preproc = nil, postproc = nil)
+	ch = chrs.shift
+	if node = @Tree[ch]
+	  if chrs.empty?
+	    Trie.fail ErrNodeAlreadyExists
+	  else
+	    node.create_subnode(chrs, preproc, postproc)
+	  end
+	else
+	  if chrs.empty?
+	    node = Node.new(preproc, postproc)
+	  else
+	    node = Node.new
+	    node.create_subnode(chrs, preproc, postproc)
+	  end
+	  @Tree[ch] = node
+	end
+	node
+      end
+      
+      def match(chrs, op = "")
+	print "match: ", chrs, ":", op, "\n" if $DEBUG
+	if chrs.empty?
+	  if @preproc.nil? || @preproc.call(op, chrs)
+	    printf "op1: %s\n", op if $DEBUG
+	    @postproc.call(op, chrs)
+	    ""
+	  else
+	    nil
+	  end
+	else
+	  ch = chrs.shift
+	  if node = @Tree[ch]
+	    if ret = node.match(chrs, op+ch)
+	      return ch+ret
+	    elsif @postproc and @preproc.nil? || @preproc.call(op, chrs)
+	      chrs.unshift ch
+	      printf "op2: %s\n", op if $DEBUG
+	      @postproc.call(op, chrs)
+	      return ""
+	    else
+	      chrs.unshift ch
+	      return nil
+	    end
+	  else
+	    if @postproc and @preproc.nil? || @preproc.call(op, chrs)
+	      printf "op3: %s\n", op if $DEBUG
+	      chrs.unshift ch
+	      @postproc.call(op, chrs)
+	      return ""
+	    else
+	      chrs.unshift ch
+	      return nil
+	    end
+	  end
+	end
+      end
+    end
+    
+    def initialize
+      @head = Node.new("")
+    end
+    
+    def def_rule(token, preproc = nil, postproc = nil)
+      node = search(token, :CREATE)
+#      print node.inspect, "\n" if $DEBUG
+      node.preproc(preproc)
+      if iterator?
+	node.postproc(proc)
+      elsif postproc
+	node.postproc(postproc)
+      end
+    end
+    
+    def def_rules(*tokens)
+      if iterator?
+	p = proc
+      end
+      for token in tokens
+	def_rule(token, nil, p)
+      end
+    end
+    
+    def preporc(token)
+      node = search(token)
+      node.preproc proc
+    end
+    
+    def postproc(token)
+      node = search(token)
+      node.postproc proc
+    end
+    
+    def search(token, opt = nil)
+      @head.search(token.split(//), opt)
+    end
+    
+    def match(token)
+      token = token.split(//) if token.kind_of?(String)
+      ret = @head.match(token)
+      printf "match end: %s:%s", ret, token.inspect if $DEBUG
+      ret
+    end
+    
+    def inspect
+      format("<Trie: @head = %s>", @head.inspect)
+    end
+  end
+  
+  if /^-tt(.*)$/ =~ ARGV[0]
+#    Tracer.on
+    case $1
+    when "1"
+      tr = Trie.new
+      print "0: ", tr.inspect, "\n"
+      tr.def_rule("=") {print "=\n"}
+      print "1: ", tr.inspect, "\n"
+      tr.def_rule("==") {print "==\n"}
+      print "2: ", tr.inspect, "\n"
+      
+      print "case 1:\n"
+      print tr.match("="), "\n"
+      print "case 2:\n"
+      print tr.match("=="), "\n"
+      print "case 3:\n"
+      print tr.match("=>"), "\n"
+      
+    when "2"
+      tr = Trie.new
+      print "0: ", tr.inspect, "\n"
+      tr.def_rule("=") {print "=\n"}
+      print "1: ", tr.inspect, "\n"
+      tr.def_rule("==", proc{FALSE}) {print "==\n"}
+      print "2: ", tr.inspect, "\n"
+      
+      print "case 1:\n"
+      print tr.match("="), "\n"
+      print "case 2:\n"
+      print tr.match("=="), "\n"
+      print "case 3:\n"
+      print tr.match("=>"), "\n"
+    end
+    exit
+  end
+  
+  module CONTEXT
+    def _=(value)
+      @_ = value
+    end
+    
+    def _
+      @_
+    end
+    
+    def quit
+      exit
+    end
+    
+    def trace_load(opt = nil)
+      if opt
+	@Trace_require = opt
+      else
+	@Trace_require = !@Trace_require
+      end
+      print "Switch to load/require #{unless @Trace_require; ' non';end} trace mode.\n"
+      if @Trace_require
+	eval %{
+	  class << self
+	    alias load rbc_load
+	    alias require rbc_require
+	  end
+	}
+      else
+	eval %{
+	  class << self
+	    alias load rbc_load_org
+	    alias require rbc_require_org
+	  end
+	}
+      end
+      @Trace_require
+    end
+    
+    alias rbc_load_org load
+    def rbc_load(file_name)
+      return true if load_sub(file_name)
+      raise LoadError, "No such file to load -- #{file_name}"
+    end
+
+    alias rbc_require_org require
+    def rbc_require(file_name)
+      rex = Regexp.new("#{Regexp.quote(file_name)}(\.o|\.rb)?")
+      return false if $".find{|f| f =~ rex}
+
+      case file_name
+      when /\.rb$/
+	if load_sub(file_name)
+	  $:.push file_name
+	  return true
+	end
+      when /\.(so|o|sl)$/
+	require_org(file_name)
+      end
+      
+      if load_sub(f = file_name + ".rb")
+	  $:.push f
+      end
+      require(file_name)
+    end
+
+    def load_sub(fn)
+      if fn =~ /^#{Regexp.quote(File::Separator)}/
+	return false unless File.exist?(fn)
+	BC.new.eval_input FileInputMethod.new(fn), self, CONFIG[:BIND]
+	return true
+      end
+      
+      for path in $:
+	if File.exist?(f = File.join(path, fn))
+	  BC.new.eval_input FileInputMethod.new(f), self, CONFIG[:BIND]
+	  return true
+	end
+      end
+      return false
+    end
+
+    def inspect(opt = nil)
+      if opt
+	CONFIG[:INSPECT] = opt
+      else
+	CONFIG[:INSPECT] = !$INSPECT
+      end
+      print "Switch to#{unless $INSPECT; ' non';end} inspect mode.\n"
+      $INSPECT
+    end
+    
+    def run
+      CONFIG[:BIND] = proc
+
+      if CONFIG[:TRACE_LOAD]
+	trace_load true
+      end
+  
+      for m in CONFIG[:LOAD_MODULES]
+	begin
+	  require m
+	rescue
+	  print $@[0], ":", $!.type, ": ", $!, "\n"
+	end
+      end
+  
+      if !$0.equal?(CONFIG[0])
+	io = FileInputMethod.new($0)
+      elsif defined? Readline
+	io = ReadlineInputMethod.new
+      else
+	io = StdioInputMethod.new
+      end
+
+      BC.new.eval_input io, self, CONFIG[:BIND]
+    end
+  end
+  
+  class InputMethod
+    attr :prompt, TRUE
+    
+    def gets
+    end
+    public :gets
+  end
+  
+  class StdioInputMethod < InputMethod
+    def gets
+      print @prompt
+      $stdin.gets
+    end
+  end
+  
+  class FileInputMethod < InputMethod
+    def initialize(file)
+      @io = open(file)
+    end
+
+    def gets
+      l = @io.gets
+      print @prompt, l
+      l
+    end
+  end
+
+  if CONFIG[:USE_READLINE]
+    begin
+      require "readline"
+      print "use readline module\n"
+      class ReadlineInputMethod < InputMethod
+	include Readline 
+	def gets
+	  if l = readline(@prompt, TRUE)
+	    l + "\n"
+	  else
+	    l
+	  end
+	end
+      end
+    rescue
+      CONFIG[:USE_READLINE] = FALSE
+    end
+  end
+end
+
+extend BC_APPLICATION__::CONTEXT
+run{}