From: Martin DeMello <martindemello@...>
Date: 2008-01-30T07:07:31+09:00
Subject: neat idea from arc

Paul Graham just released Arc (http://paulgraham.com/arc0.html), a
lisp dialect with an emphasis on "quick-and-dirty" exploratory
programming, and compactness of code. One of the ideas he threw in
seems like it might fit well into Ruby too - when filtering functions
like keep and rem (select and reject) are given a value rather than a
function, they implicitly construct the equality function and pass
that in instead. The ruby equivalent would be to have select, reject,
partition, any? and all? (and possibly some others I'm overlooking) do
the following:

def select(arg, &blk)
  if block_given?
    old_select(&blk)
  else
    old_select {|x| arg === x}
  end
end

and likewise for the others

So we can write, for instance

ints = input.select Integer

lcase = words.reject /[A-Z]/

and so on. What say you?

martin