# Author::    Nicolas Pouillard  <ertai@lrde.epita.fr>.
# Copyright:: Copyright (c) 2004, 2005 TTK team. All rights reserved.
# License::   LGPL
# $Id: symtbl.rb 567 2005-04-13 08:00:06Z polrop $


require 'symtbl'


module TTK

  class SymTbl < SymTbl
    include Mutex_m

    def initialize ( father_env=nil, default=nil )
      @frozen_keys = []
      super
    end

    def [] ( aKey )
      super
    end

    def []= ( k, v )
      if frozen_key?(k)
        raise(TypeError, 'can\'t modify frozen key')
      else
        super
      end
    end

    def frozen_key? ( k )
      @local.has_key?(k) and @frozen_keys.include?(k)
    end

    def freeze_key ( k )
      unless frozen_key?(k)
        @frozen_keys << k
        self[k].freeze
      end
    end

  end # class SymTbl

end # module TTK

class Object
  def symtbl_gsub ( symtbl )
    nil
  end

  def do_symtbl_gsub ( symtbl )
    result = symtbl_gsub(symtbl)
    return (result.nil?)? self : result
  end
end

class Hash
  def symtbl_gsub ( symtbl )
    changed = false
    res = self.class.new
    each do |k,v|
      new_k = k.symtbl_gsub(symtbl)
      new_v = v.symtbl_gsub(symtbl)
      changed = true if new_k or new_v
      res[new_k || k] = (new_v || v)
    end
    changed ? res : nil
  end
end

class Array
  def symtbl_gsub ( symtbl )
    changed = false
    res = self.class.new
    each do |e|
      changed = true if new_e = e.symtbl_gsub(symtbl)
      res << (new_e || e)
    end
    changed ? res : nil
  end
end

class SymTbl
  def symtbl_gsub ( symtbl )
    nil
  end
end

class Pathname
  def symtbl_gsub ( symtbl )
    res = to_s.symtbl_gsub(symtbl)
    return self.class.new(res) unless res.nil?
  end
end

class Regexp
  def symtbl_gsub ( symtbl )
    res = source.symtbl_gsub(symtbl)
    return self.class.new(res) unless res.nil?
  end
end

class Symbol
  def symtbl_gsub ( symtbl )
    res = to_s.symtbl_gsub(symtbl)
    return res.to_sym unless res.nil?
  end
end

class String
  def symtbl_gsub ( symtbl )
    return gsub(/<<(.*?)>>/) { symtbl[$1.to_sym] || $& } if self =~ /<<(.*)>>/
  end
end