From: Ryan Pavlik <rpav@...>
Date: 2003-11-17T19:03:55+09:00
Subject: Proposal for a new operator - .=

OK so it's late, I'm not thinking straight, and I thought I'd post
this.

Proposal for a new operator - .=
================================

Ruby has a number of useful operators, including some for combined
operation/assignment, such as +=, -=, etc.

This proposal is for a new operation/assignment operator, .=
(period-equals).  Existing operators follow this form:

    a += b      # =>   a = a + b
    a -= b      # =>   a = a - b

The proposed .= operator would follow in an identical fashion:

    a .= b      # =>   a = a.b

For instance, some practical applications:

    # We're passed an object, we want to do work on it
    def foo(x)
       x .= dup
       :
    end

    # We have an operation for which there is no bang! method:
    hash .= invert

    # Similar to the last, we have an object which a bang method
    # is impossible:
    i  = 5 
    i .= succ  # => 6

    # Following from that, we can't really change what an object _is_,
    # but with .= we don't need to:
    c  = 65
    c .= chr   # => "A"
    

This has the following important advantages:

    *  It provides a generic operation/assignment operator

    *  Much like existing operation/assignment operators, it saves
       space and increases readability

    *  It confuses Perl programmers

Support this new operator for Ruby!
---------------------------------------------------------------------------

(The preceding was 90% a joke.  I don't actually have any serious
expectation of a .= operator in Ruby.  I imagine it would be a bit
hairy to implement.  I actually thought of it after doing "s = s.dup"
a few times, and there may be a few good uses for it, but... this was
for entertainment purposes only. ;-)

-- 
Ryan Pavlik <rpav@mephle.com>

"Every day shall be sword day." - 8BT