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Groups > comp.lang.python > #69502
| References | (9 earlier) <CALwzidkTRYbpeBCY7gxSXa=ZNimaAe69mGbT0d9sbehHfHgvOw@mail.gmail.com> <533A768F.5080102@rece.vub.ac.be> <mailman.8790.1396344274.18130.python-list@python.org> <87txadtmwq.fsf@elektro.pacujo.net> <CALwzidkr8Def8-dgKU-qfbcc+7ueX8xSA5a8M7x2Sif7P81mOQ@mail.gmail.com> |
|---|---|
| Date | 2014-04-01 21:39 +1100 |
| Subject | Re: unicode as valid naming symbols |
| From | Chris Angelico <rosuav@gmail.com> |
| Newsgroups | comp.lang.python |
| Message-ID | <mailman.8793.1396348750.18130.python-list@python.org> (permalink) |
On Tue, Apr 1, 2014 at 8:58 PM, Ian Kelly <ian.g.kelly@gmail.com> wrote:
> Setting aside the fact that C doesn't have anonymous functions, I'll
> approximate it as best I can:
>
> static int n = 3;
>
> int f()
> {
> return n;
> }
>
> int main()
> {
> n = 7;
> return f();
> }
>
> C: 10
> Scheme: 20
And the less trivial the example, the more difference you'll see. This
is Scheme inside LilyPond, a little translator that lets me input
lyrics in a tidy way that can then be turned into something that works
well with both MIDI Karaoke and printed score:
#(define (bang2slashn lst) (
cond ((null? lst) 0)
(else (begin
(if (equal? (ly:music-property (car lst) 'name) 'LyricEvent)
(let ((txt (ly:music-property (car lst) 'text)))
(if (equal? (string-ref txt 0) #\!) (begin
; Debugging display
; (display (ly:music-property (car lst) 'name)) (display "
- ") (display txt) (newline)
; Prepend a newline instead of the exclamation mark -
works for both MIDI Karaoke and page layout
(ly:music-set-property! (car lst) 'text (string-append
"\n" (substring txt 1 (string-length txt))))
))))
(bang2slashn (ly:music-property (car lst) 'elements))
(bang2slashn (cdr lst))
))
))
% Call the above recursive function
lyr=#(define-music-function (parser location lyrics) (ly:music?)
(bang2slashn (ly:music-property lyrics 'elements))
lyrics
)
Now, this was written by a non-Scheme programmer, so it's not going to
be optimal code, but I doubt it's going to lose a huge number of
parentheses. Not counting the commented-out debugging line, that's 41
pairs of them in a short but non-trivial piece of code. Translating it
to C isn't easy, in the same way that it's hard to explain how to do
client-side web form validation in Lua; but here's an attempt. It
assumes a broadly C-like structure to LilyPond (eg that the elements
are passed as a structure; they are a tree already, as you can see by
the double-recursive function above), which is of course not the case,
but here goes:
void bang2slashn(struct element *lst)
{
while (lst)
{
if (!strcmp(lst->name, "LyricEvent"))
{
char *text = music_property(lst, "text");
/* Okay, C doesn't have string manipulation, so I cheat here */
/* If this were C++ or Pike, some notation nearer to the
original would work */
if (*text == '!') music_set_property(lst, "text", "\n" + text[1..]);
}
bang2slashn(lst->elements);
lst = lst->next;
}
}
DEFINE_MUSIC_FUNCTION(PARSER_LOCATION_LYRICS, bang2slashn);
That's nine pair parens, three braces, and one square. I assume a lot
about the supposed C-like interface to LilyPond, but I think anyone
who knows both C and Scheme would agree that I haven't been
horrendously unfair in the translation. (Though I will accept an
alternate implementation of the Scheme version. If you can cut it down
to just 26 pair parens, you'll achieve the 2:1 ratio that Ian
mentioned. And if you can cut it down to 13 pairs, you've equalled my
count.) The only way to have the C figure come up approximately equal
is to count a semicolon as if it were a pair of parens - Scheme has an
extra set of parens doing the job of separating one function call from
another. But that adds only another 5, bringing C up to a total of 18
(plus a few more if I used functions to do my string manipulation, so
let's say about 20-25) where Scheme is still at roughly twice that.
ChrisA
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unicode as valid naming symbols Mark H Harris <harrismh777@gmail.com> - 2014-03-25 13:30 -0500
Re: unicode as valid naming symbols wxjmfauth@gmail.com - 2014-03-25 11:52 -0700
Re: unicode as valid naming symbols Mark H Harris <harrismh777@gmail.com> - 2014-03-25 14:24 -0500
Re: unicode as valid naming symbols Rustom Mody <rustompmody@gmail.com> - 2014-03-25 19:16 -0700
Re: unicode as valid naming symbols MRAB <python@mrabarnett.plus.com> - 2014-03-25 19:24 +0000
Re: unicode as valid naming symbols Mark H Harris <harrismh777@gmail.com> - 2014-03-25 14:29 -0500
Re: unicode as valid naming symbols Marko Rauhamaa <marko@pacujo.net> - 2014-03-25 21:48 +0200
Re: unicode as valid naming symbols Skip Montanaro <skip@pobox.com> - 2014-03-25 14:54 -0500
Re: unicode as valid naming symbols Cameron Simpson <cs@zip.com.au> - 2014-03-26 09:16 +1100
Re: unicode as valid naming symbols Ian Kelly <ian.g.kelly@gmail.com> - 2014-03-25 13:49 -0600
Re: unicode as valid naming symbols Tim Chase <python.list@tim.thechases.com> - 2014-03-25 15:29 -0500
Re: unicode as valid naming symbols Ethan Furman <ethan@stoneleaf.us> - 2014-03-25 15:47 -0700
Re: unicode as valid naming symbols Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-03-25 23:58 +0000
Re: unicode as valid naming symbols Mark H Harris <harrismh777@gmail.com> - 2014-03-27 10:28 -0500
Re: unicode as valid naming symbols Rustom Mody <rustompmody@gmail.com> - 2014-03-27 08:51 -0700
Re: unicode as valid naming symbols Mark H Harris <harrismh777@gmail.com> - 2014-03-27 11:03 -0500
Re: unicode as valid naming symbols Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2014-03-28 12:45 +1300
Re: unicode as valid naming symbols MRAB <python@mrabarnett.plus.com> - 2014-03-27 17:17 +0000
Re: unicode as valid naming symbols Rustom Mody <rustompmody@gmail.com> - 2014-03-27 10:53 -0700
Re: unicode as valid naming symbols Ian Kelly <ian.g.kelly@gmail.com> - 2014-03-27 10:22 -0600
Re: unicode as valid naming symbols Rustom Mody <rustompmody@gmail.com> - 2014-03-27 10:41 -0700
Re: unicode as valid naming symbols Chris Angelico <rosuav@gmail.com> - 2014-03-28 03:23 +1100
Re: unicode as valid naming symbols Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2014-03-31 11:55 +0200
Re: unicode as valid naming symbols Ian Kelly <ian.g.kelly@gmail.com> - 2014-03-31 11:40 -0600
Re: unicode as valid naming symbols Tim Chase <python.list@tim.thechases.com> - 2014-03-31 13:02 -0500
Re: unicode as valid naming symbols Ian Kelly <ian.g.kelly@gmail.com> - 2014-03-31 12:10 -0600
Re: unicode as valid naming symbols Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2014-03-31 21:31 +0200
Re: unicode as valid naming symbols Terry Reedy <tjreedy@udel.edu> - 2014-03-31 16:12 -0400
Re: unicode as valid naming symbols Terry Reedy <tjreedy@udel.edu> - 2014-03-31 16:15 -0400
Re: unicode as valid naming symbols Marko Rauhamaa <marko@pacujo.net> - 2014-03-31 23:34 +0300
Re: unicode as valid naming symbols Ian Kelly <ian.g.kelly@gmail.com> - 2014-03-31 18:47 -0600
Re: unicode as valid naming symbols David Hutto <dwightdhutto@gmail.com> - 2014-03-31 23:58 -0400
Re: unicode as valid naming symbols David Hutto <dwightdhutto@gmail.com> - 2014-04-01 00:11 -0400
Re: unicode as valid naming symbols Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2014-04-01 10:19 +0200
Re: unicode as valid naming symbols Ian Kelly <ian.g.kelly@gmail.com> - 2014-04-01 03:18 -0600
Re: unicode as valid naming symbols Marko Rauhamaa <marko@pacujo.net> - 2014-04-01 12:32 +0300
Re: unicode as valid naming symbols Ian Kelly <ian.g.kelly@gmail.com> - 2014-04-01 03:58 -0600
Re: unicode as valid naming symbols Marko Rauhamaa <marko@pacujo.net> - 2014-04-01 15:02 +0300
Re: unicode as valid naming symbols Chris Angelico <rosuav@gmail.com> - 2014-04-01 23:54 +1100
Re: unicode as valid naming symbols Marko Rauhamaa <marko@pacujo.net> - 2014-04-01 16:16 +0300
Re: unicode as valid naming symbols Chris Angelico <rosuav@gmail.com> - 2014-04-02 00:32 +1100
Re: unicode as valid naming symbols Marko Rauhamaa <marko@pacujo.net> - 2014-04-01 18:59 +0300
Re: unicode as valid naming symbols Rustom Mody <rustompmody@gmail.com> - 2014-04-01 19:58 -0700
Re: unicode as valid naming symbols Rustom Mody <rustompmody@gmail.com> - 2014-04-01 20:16 -0700
Re: unicode as valid naming symbols Marko Rauhamaa <marko@pacujo.net> - 2014-04-02 08:55 +0300
Re: unicode as valid naming symbols Chris Angelico <rosuav@gmail.com> - 2014-04-01 21:39 +1100
Re: unicode as valid naming symbols Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2014-04-01 12:37 +0200
Re: unicode as valid naming symbols Chris Angelico <rosuav@gmail.com> - 2014-04-01 21:58 +1100
Re: unicode as valid naming symbols Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2014-04-01 13:59 +0200
Re: unicode as valid naming symbols Roy Smith <roy@panix.com> - 2014-04-01 08:29 -0400
Re: unicode as valid naming symbols Chris Angelico <rosuav@gmail.com> - 2014-04-02 00:08 +1100
Re: unicode as valid naming symbols Rustom Mody <rustompmody@gmail.com> - 2014-04-01 06:34 -0700
Re: unicode as valid naming symbols Chris Angelico <rosuav@gmail.com> - 2014-04-02 00:00 +1100
Re: unicode as valid naming symbols Ned Batchelder <ned@nedbatchelder.com> - 2014-04-01 09:33 -0400
Re: unicode as valid naming symbols Chris Angelico <rosuav@gmail.com> - 2014-04-02 00:44 +1100
Re: unicode as valid naming symbols Rustom Mody <rustompmody@gmail.com> - 2014-04-01 06:58 -0700
Re: unicode as valid naming symbols Ian Kelly <ian.g.kelly@gmail.com> - 2014-04-01 09:53 -0600
Re: unicode as valid naming symbols MRAB <python@mrabarnett.plus.com> - 2014-03-26 02:56 +0000
Re: unicode as valid naming symbols Chris Angelico <rosuav@gmail.com> - 2014-03-26 14:09 +1100
Re: unicode as valid naming symbols Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2014-03-26 09:25 +0100
Re: unicode as valid naming symbols Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2014-03-26 09:52 +0100
Re: unicode as valid naming symbols Ian Kelly <ian.g.kelly@gmail.com> - 2014-03-26 10:37 -0600
Re: unicode as valid naming symbols Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2014-03-27 10:36 +0100
Re: unicode as valid naming symbols Rustom Mody <rustompmody@gmail.com> - 2014-03-27 08:10 -0700
Re: unicode as valid naming symbols Tim Chase <python.list@tim.thechases.com> - 2014-03-27 10:34 -0500
Re: unicode as valid naming symbols random832@fastmail.us - 2014-03-28 14:55 -0400
Re: unicode as valid naming symbols Rustom Mody <rustompmody@gmail.com> - 2014-03-28 22:00 -0700
Re: unicode as valid naming symbols Chris Angelico <rosuav@gmail.com> - 2014-03-29 16:12 +1100
Re: unicode as valid naming symbols Ben Finney <ben+python@benfinney.id.au> - 2014-03-29 16:32 +1100
Re: unicode as valid naming symbols Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2014-03-29 14:11 -0400
Re: unicode as valid naming symbols Chris Angelico <rosuav@gmail.com> - 2014-03-30 09:01 +1100
Re: unicode as valid naming symbols Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2014-03-30 19:16 +1300
Re: unicode as valid naming symbols Mark H Harris <harrismh777@gmail.com> - 2014-03-25 14:29 -0500
Re:unicode as valid naming symbols Dave Angel <davea@davea.name> - 2014-03-25 15:45 -0400
Re: unicode as valid naming symbols Terry Reedy <tjreedy@udel.edu> - 2014-03-25 22:26 -0400
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