RE: Why aren't `find`, `find-if`, `remove-if` part of Emacs Lisp?

[Doug Lewan]

While I won't make assertions about how Emacs Lisp as a language should be, I 
am comfortable saying that I write code like the following a lot:

    (delete nil (mapcar ...))

,Douglas
Douglas Lewan
Shubert Ticketing
(201) 489-8600 ext 224

LISP: The most intelligent way to misuse a computer.

> -----Original Message-----
> From: help-gnu-emacs-bounces+dougl=shubertticketing.com@gnu.org
> [mailto:help-gnu-emacs-bounces+dougl=shubertticketing.com@gnu.org] On
> Behalf Of Nicolas Petton
> Sent: Tuesday, 2014 June 17 14:37
> To: Stefan Monnier
> Cc: help-gnu-emacs@gnu.org
> Subject: Re: Why aren't `find`, `find-if`, `remove-if` part of Emacs
> Lisp?
> 
> 
> Stefan Monnier writes:
> 
> >> Emacs Lisp is a great Lisp dialect, but I miss `find`, `find-if`,
> >> `remove-if`, etc. iteration functions a lot. Sure, I can require cl-
> lib
> >> or use dash, but I'm wondering why these functions are not part of
> the
> >> base language?
> >
> > Not sure what you mean.  Most languages I know provide list
> operations
> > via libraries.  Why should Elisp be different?
> 
> What I mean is that Elisp do not have `remove-if` (or any equivalent
> function, I don't necessarily mean the CL remove-if function), a
> function that I think could be in the language.
> 
> To filter lists, one has to implement its own version of this function,
> or require an external library. Same goes for `find-if`.
> 
> I was wondering if Emacs Lisp was lacking this function for some reason
> (or did I completely miss it? could be too). If not, why not add it to
> the language? It looks to me like a badly missing feature, I think
> filtering collections is something very common.
> 
> Cheers,
> Nico