Han-Wen Nienhuys <[email protected]> writes:
> On Thu, Jan 13, 2011 at 10:19 AM, David Kastrup <[email protected]> wrote:
>>
>> Hi,
>>
>> in note-collision.cc I read the following:
>>
>> Direction d = UP;
>> do
>> {
>> vector<Grob*> &clashes (clash_groups[d]);
>> vector_sort (clashes, Note_column::shift_less);
>> }
>> while ((flip (&d)) != UP);
>>
>> Uh, is there any reason not to just write
>>
>> vector_sort (clash_groups[UP], Note_column::shift_less);
>> vector_sort (clash_groups[DOWN], Note_column::shift_less);
>>
>> I find it somewhat strange to make a loop for two simple function calls.
>
> In this particular case it may not matter, but the
>
> while ((flip(&d) != UP)
>
> is a common idiom in the lilypond source code, and you should get used
> to it reading the source code.
It is not a pretty idiom. Something like
for (d in [UP,DOWN]) ...
would be much nicer and clearer. Doesn't C++ have some more useful
idiom for iterators or so?
I think I might even prefer
while ((flip(&d) == DOWN)
since in that way at least both directions are mentioned. But the whole
flipping business seems awkward when just two directions are involved.
Something like
for (d=UP;;d=DOWN) {
...
if (d == DOWN)
break;
}
would be somewhat prettier in my book and involve less calculation.
> Overall, I prefer to have programmatic constructs (like this while
> loop) over unrolling loops by hand, and making symmetry of left/right
> and up/down explicit in this way.
Uh, a loop with a single simple function call in it?
--
David Kastrup
_______________________________________________
lilypond-devel mailing list
[email protected]
http://lists.gnu.org/mailman/listinfo/lilypond-devel
