From: James H.
Subject: *p Functions
Date: 
Message-ID: <1163562330.477511.151830@b28g2000cwb.googlegroups.com>
Hi there!

I'm a little new to LISP, and I've noticed there are a lot of function
(method?) names ending with a 'p'.  For instance, listp, boundp.  What
does the 'p' mean?

James H
From: Ray
Subject: Re: *p Functions
Date: 
Message-ID: <1163569797.198897.119320@m73g2000cwd.googlegroups.com>
James H. wrote:

> Hi there!
>
> I'm a little new to LISP, and I've noticed there are a lot of function
> (method?) names ending with a 'p'.  For instance, listp, boundp.  What
> does the 'p' mean?

Hey James,

Googling for "Lisp coding convention" yields this:

http://www.cliki.net/Naming%20conventions

"foop	predicate (also foo-p); see notes below for when to hyphenate"

HTH,
Ray

> 
> James H
From: James H.
Subject: Re: *p Functions
Date: 
Message-ID: <1163574030.259096.110670@e3g2000cwe.googlegroups.com>
Ray wrote:
> Googling for "Lisp coding convention" yields this:
>
> http://www.cliki.net/Naming%20conventions
>
> "foop	predicate (also foo-p); see notes below for when to hyphenate"
>
> HTH,
> Ray
Thanks for the link Ray!

And thank you everyone for the info!

James H
From: Ari Johnson
Subject: Re: *p Functions
Date: 
Message-ID: <m2hcx1tl3r.fsf@hermes.theari.com>
"James H." <·············@gmail.com> writes:

> Hi there!
>
> I'm a little new to LISP, and I've noticed there are a lot of function
> (method?) names ending with a 'p'.  For instance, listp, boundp.  What
> does the 'p' mean?
>
> James H

"Predicate," which in computing means a boolean-valued function.
From: Adam
Subject: Re: *p Functions
Date: 
Message-ID: <eje2qo$v79$1@lust.ihug.co.nz>
James H. wrote:

> Hi there!
> 
> I'm a little new to LISP, and I've noticed there are a lot of function
> (method?) names ending with a 'p'.  For instance, listp, boundp.  What
> does the 'p' mean?
> 
> James H

p here means "predicate" - as I understand it.  Useful for testing for a
true or false compare condition. 

Without referring to the Common Lisp, Cmucl or other manuals, and I wonder
why you don't do this yourself, here is an interesting link; 

http://en.wikipedia.org/wiki/Predicate
From: Barry Margolin
Subject: Re: *p Functions
Date: 
Message-ID: <barmar-3E158B.23015314112006@comcast.dca.giganews.com>
In article <············@lust.ihug.co.nz>, Adam <······@example.com> 
wrote:

> James H. wrote:
> 
> > Hi there!
> > 
> > I'm a little new to LISP, and I've noticed there are a lot of function
> > (method?) names ending with a 'p'.  For instance, listp, boundp.  What
> > does the 'p' mean?
> > 
> > James H
> 
> p here means "predicate" - as I understand it.  Useful for testing for a
> true or false compare condition. 
> 
> Without referring to the Common Lisp, Cmucl or other manuals, and I wonder
> why you don't do this yourself, here is an interesting link; 
> 
> http://en.wikipedia.org/wiki/Predicate

Unless you already know that these functions are called "predicates", 
how would you find this entry?  And if he did know that this is the 
term, he probably could have guessed at the answer to his question.

-- 
Barry Margolin, ······@alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***
*** PLEASE don't copy me on replies, I'll read them in the group ***
comp.lang.lisp / 2006 / nov