From: Wesley J Landaker <wjl@...>
Date: 2003-11-20T14:05:37+09:00
Subject: "stereotyping" thread

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Why not just use empty modules for all this type-checking? This isn't=20
very useful to me personally, but it seems to do everything that has=20
been mentioned in this whole "stereotyping" thread (i.e. emits warnings=20
if the passed in types haven't been manually tagged by a programmer as=20
implementing a particular interface):

class Object
  def typecheck(type)
    unless self.kind_of?(type)
      $stderr.puts "WARNING: expected #{type}, got #{self.class}"
    end
  end
end

module SomeInterface
end

def function_expecting_SomeInterface(var)
  var.typecheck(SomeInterface)
end

def function_expecting_Numeric(var)
  var.typecheck(Numeric)
end

class SomeClassThatClaimsToSupportSomeInterface
  include SomeInterface
end

class String
  #mark Strings as implementing some interface
  include SomeInterface
end

I'm not sure how special language syntax would help anything in this=20
regard...

=2D-=20
Wesley J. Landaker - wjl@icecavern.net
OpenPGP FP: 4135 2A3B 4726 ACC5 9094  0097 F0A9 8A4C 4CD6 E3D2


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