On Friday, 9 August 2013 at 03:30:16 UTC, SteveGuo wrote:
I suggest that change keyword *for_each* to *for* since *for*
is clear enough and
less letters, like C++11 does.
Decent suggestion, but I don't think Walter, Andrei or any of the
committers want to break everyone's code just to shorten some
syntax.
As a proposal, however, it's not bad, and like you say it exists
in other languages:
// Go
for key, val := range x {} // where x is an array, slice or
map
// Java
for (int x in y) {}
// C++11
for (int &x : y) {}
// Python (or use iter(), range(), xrange(), etc)
for x in y: pass
Which are similar to D's foreach:
foreach (key, value; x) {} // where x is a suitable range
I agree that the following would be unambiguous (whichever syntax
we decide is better):
for (key, value; x) {}
for (key, value : x) {}
But it doesn't offer enough benefit to make a breaking change or
introduce redundant syntax. Saving 4 chararters isn't enough
justification.
Also, I don't particularly like for_reverse, since you can't use
a traditional for-loop syntax with for_reverse:
// would be syntax error
for_reverse (i = 0; i < 5; i++) {}
// but this works just fine
foreach_reverse(i; 0 .. 5);
And D doesn't stand alone in the 'foreach' arena:
// C#
foreach(int x in y) {}
// Perl
foreach (@arr) {
print $_;
}
// PHP
foreach($set as $value) {}
foreach ($set as $key => $value) {}
// Scala
some_items foreach println
I don't really see a compelling reason to switch. Then again,
this is only my opinion, so I can't speak for the community.
