From: Joel VanderWerf <vjoel@...>
Date: 2003-07-17T07:53:59+09:00
Subject: Re: Other languages' features in Ruby

Phil Tomson wrote:
> In article <D3E034C6-B798-11D7-ACD8-00039381462A@thingmagic.com>,
> Ben Giddings  <ben@thingmagic.com> wrote:
...

>>On Wednesday, July 16, 2003, at 09:36  AM, Peter Hickman wrote:
...
>>>Lisp programmers have enquired about macros (occasionally).
>>
>>Are there good ways of doing what Lisp macros do for you?
> 
> 
> Perl has input filters (see the perlfilter docs) that sort of act like a pre-processor 
> for yout source.  This was originally intended for encrypting source-code, but now is 
> used for lots of other purposes.  Perl even has a command line argument (-p, I believe) 
> that will pass the source through the c pre-processor before Perl interprets it.
> 
> I wonder how difficult it would be to do input filters for Ruby?
> 
> On the otherhand, it's probably not a feature needed in Ruby as much as it is in Perl.

Would the filter operate on strings or parse trees?

Strings wouldn't satisfy the Lisp folks, because they're used to 
s-expressions.