From: Jim Weirich <jim@...>
Date: 2004-08-04T03:27:36+09:00
Subject: Re: __call__ equivalent?


Kevin Howe said:
> Does Ruby have an equivalent of Python's __call__ method?

Yes and no.

If you are asking:  Can you define a call operator in a class so that
instances of that can pretend to be called with a function-like syntax?

Then the answer is no.  Mainly because there is no "call" operator in Ruby.

If you are asking: Can you define objects that act like functions (ie.
functors).

Then then answer is yes.  Proc and Continuations are objects that act like
functions.  To call them, you send them a "call" message with the
appropriate arguments.  To define your own callable object, just implement
the "call" method.  Also the "[]" operator is often an alias for call.

-- 
-- Jim Weirich     jim@weirichhouse.org    http://onestepback.org
-----------------------------------------------------------------
"Beware of bugs in the above code; I have only proved it correct,
not tried it." -- Donald Knuth (in a memo to Peter van Emde Boas)