Re: moving more cl seq/mapping support into core

[Daniel Colascione]

On 9/25/2010 8:30 AM, Leo wrote:
> On 2010-09-25 16:23 +0100, Drew Adams wrote:
>> Sorry, I don't get it.  What is TEST for?  It is typically for a binary
>> predicate such as `equal' - but we already have PREDICATE here.  And just 
>> what
>> is second class here (if TEST is not added)?
> 
> `remove-if' as defined in cl.el can not be used in a package intended to
> be included in GNU Emacs due to the use of cl run time functions.
> 
> So to move this function into elisp Miles (I think) proposed that we
> give up some of its keyword arguments since they mostly are not used and
> turned the keyword :test argument into an optional one.

Why bother? A compiler-macro can examine a call to remove-if, see
whether it recognizes the keyword arguments, and if it does, transform
the whole call into something more lightweight. You retain the current
function's expressive power and CL compatibility while losing nothing in
performance.