MIME-Version: 1.0
References: <52623D5C.1090607@clear.net.nz>
            <526ACD96.9020304@morningstar2.co.uk>
            <CACKZBPWVDjP2BeVWHGvMKtGR5C+4K1z-tVh3eFDcSKOVGa5tew@mail.gmail.com> <526ADFC9.9070908@morningstar2.co.uk>
            <59274.50.67.64.130.1382739473.squirrel@trmail.triumf.ca>
            <CACKZBPWwau-rN6FvjhKgtEudLRG1tE46Ghbj35umpoQuCarXEg@mail.gmail.com>
            <CACKZBPWqiT-FKS7WKS0UzphSzg44Z3dQkri=6ATx6RHSxdQ83g@mail.gmail.com>
            <49834.142.90.112.22.1382754768.squirrel@trmail.triumf.ca>
Content-Type: text/plain; charset=ISO-8859-1
Message-ID:  <CACKZBPXGPdDY-ACnzvjHHFN2SYWazCL0kgLOUzvdTOVFOyN-VA@mail.gmail.com>
Date:         Sat, 26 Oct 2013 15:00:47 +0200
Reply-To: Mailing list for the LaTeX3 project
              <LATEX-L@LISTSERV.UNI-HEIDELBERG.DE>
Sender: Mailing list for the LaTeX3 project <LATEX-L@LISTSERV.UNI-HEIDELBERG.DE>
From: Michiel Helvensteijn <mhelvens@GMAIL.COM>
Subject: Re: uppercasing
To: LATEX-L@LISTSERV.UNI-HEIDELBERG.DE
In-Reply-To:  <49834.142.90.112.22.1382754768.squirrel@trmail.triumf.ca>
Precedence: list
Envelope-To: <rainer.schoepf@GMX.NET>
Status: R

On Sat, Oct 26, 2013 at 4:32 AM, Donald Arseneau <asnd@triumf.ca> wrote:

>> But the functional programming concept doesn't really fit the expl3
>> concept, except for token lists.
>
> I'm not sure if the expl3 "map" is a straight "foreach" or a
> list accumulator.  There are several "*map*" definitions in
> expl3 internals.  The one you mean, Does it convert a list of
> x,y,z to a list of f(x),f(y),f(z)?  If so, it is a proper
> mapping operation.  Or does it just spit out f(x), f(y), and
> f(z) in turn?  Then it should just be "foreach".

Exactly. The expl3 map functions visit each element of a
data-structure in turn, apply the provided function, then leave the
result in the input stream. That's why I was thinking 'foreach' would
have been a better name. And indeed, the provided function doesn't
have to be pure or side-effect free. An expl3 mapping function is
really a looping construct.

-- 
www.mhelvens.net