nack.rb in facets-0.9.0

- old
+ new
@@ -1,128 +2 @@
-#:title: NackClass
-#--
-# NackClass
-# v 1.0
-#
-# Copyright (c) 2005 Thomas Sawyer
-#
-# Ruby License
-#
-# This module is free software. You may use, modify, and/or redistribute this
-# software under the same terms as Ruby.
-# 
-# This program is distributed in the hope that it will be useful, but WITHOUT
-# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
-# FOR A PARTICULAR PURPOSE.
-#
-#
-# $Id: nack.rb,v 1.0 2005/04/28 03:10:10 transami Exp $
-#
-# ==========================================================================
-# Revision History ::
-# YYYY.MM.DD  Ver. Dev.      Description
-# --------------------------------------------------------------------------
-# 2005.04.28  1.0  Trans     * Minor modifications to documentation.
-# ==========================================================================
-# To Do ::
-# * I beleive this class has even more potential yet.
-#   It would be interesting to see if a catch/try correction
-#   facility could be built into it too.
-# ==========================================================================
-#++
-
-# = Description
-# 
-# The NackClass is is like the NilClass except one step down.
-# Nack is never used to to mean nothingness or emptiness.
-# The Nack class is only used to report something is "a miss" w/o
-# the system raising an Exception. It's a mechanism for
-# lazy error evaluation.
-# 
-# == Usage
-# 
-#   def scalar( x )
-#     if x.kind_of?(Enumerable)
-#       return nack(ArgumentError, "Value must not be enumerable")
-#     end
-#     x
-#   end
-# 
-#   a = scaler( 1 )            #=> 1
-#   b = scaler( [1,2] )        #=> nack
-#   b.first                    #=> ArgumentError (previous)
-#   
-#   a = nail scaler( 1 )       #=> 1
-#   b = nail scaler( [1,2] )   #=> ArgumentError
-# 
-# == Author(s)
-# 
-# * Thomas Sawyer
-# 
-
-class InvalidNackError < ArgumentError
-end
-
-class NackClass
-
-  attr_reader :error, :data
-
-  def initialize(error=nil, *data, &ctrl)
-    if Class === error and error <= Exception
-      @error = error.new(*data)
-    elsif error.kind_of?( Exception )
-      @error = error
-    elsif error.kind_of?( String )
-      @error = StandardError.new(error)
-    elsif error == nil
-      @error = StandardError.new
-    else
-      raise InvalidNackError
-    end
-    @data = data
-    @ctrl = ctrl
-  end
-
-  def call(*args)
-    @ctrl.call(*args)
-  end
-
-  def call_with_data
-    @ctrl.call(*@data)
-  end
-
-  def raise_error
-    raise @error
-  end
-
-  def to_s; "n/a"; end
-  
-  def ==(x)
-    x.is_a?(NackClass)
-  end
-
-  def method_missing(meth, *args)
-    raise_error
-  end
-
-end
-
-module Kernel
-  def nack(err=nil, *data, &ctrl)
-    NackClass.new(err, *data, &ctrl)
-  end
-end
-
-# private Object method
-def nail( arg )
-  if NackClass === arg
-    arg.raise_error
-  else
-    return arg
-  end
-end
-
-#class NilClass
-#  def method_missing(meth, *args)
-#    nack()
-#  end
-#end
+require 'mega/nack.rb'
\ No newline at end of file