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digitalmars.D - Re: The empty statement ";" - when is it useful?

reply Arthur Lloyd <via google.com> writes:
Andrei Alexandrescu Wrote:


 I think he just means that the comma operator is not a strategic 
 advantage for automated code generation.



If the comma operator does not offer a strategic advantage, will it be
deprecated in favor of something that python and ruby do. I've many times
fallen into a trap when initializing multidim arrays, like:

#  int[][] a;
#  a.length = 3,4;

Also

#  struct coordinates { int x; int y; }
#  coordinates getThem() { coordinates c; c.x = 4; c.y = 5; return c; }
#  auto a = getThem();

seems very verbose when in a scripting language I can do:

#  def getThem() { (4, 5) }
#  a = getThem

Does this work, if the comma builds a tuple instead of a sequence?
Jul 29 2009
next sibling parent reply "Adam D. Ruppe" <destructionator gmail.com> writes:
On Wed, Jul 29, 2009 at 10:29:51AM -0400, Arthur Lloyd wrote:

 Also
 
 #  struct coordinates { int x; int y; }
 #  coordinates getThem() { coordinates c; c.x = 4; c.y = 5; return c; }
 #  auto a = getThem();
 
 seems very verbose when in a scripting language I can do:



It also seems very verbose in D where you can do:

auto getThem() { return tuple(4,5); }
auto a = getThem;

-- 
Adam D. Ruppe
http://arsdnet.net
Jul 29 2009
parent Arthur Lloyd <via google.com> writes:
Adam D. Ruppe Wrote:


 On Wed, Jul 29, 2009 at 10:29:51AM -0400, Arthur Lloyd wrote:

 Also
 
 #  struct coordinates { int x; int y; }
 #  coordinates getThem() { coordinates c; c.x = 4; c.y = 5; return c; }
 #  auto a = getThem();
 
 seems very verbose when in a scripting language I can do:



 It also seems very verbose in D where you can do:
 
 auto getThem() { return tuple(4,5); }
 auto a = getThem;



No, that looks quite good. Is the tuple() a D2 feature? D1/Tango doesn't seem
to have it? Why not even go so far as to make the tuple keyword completely
optional?
Jul 29 2009
prev sibling parent "Adam D. Ruppe" <destructionator gmail.com> writes:
On Wed, Jul 29, 2009 at 11:00:13AM -0400, Arthur Lloyd wrote:

 No, that looks quite good. Is the tuple() a D2 feature? D1/Tango doesn't seem
to have it? Why not even go so far as to make the tuple keyword completely
optional?



It is part of phobos 2, in std.typecons. (so you'd actually need to stick

import std.typecons;

at the top of the file to get that to compile.)


Since it is a library solution, there is no actual keyword here, nor can
it do the length thing you wanted. But, it does cover the other case quite
well, without needing to change the language at all.


-- 
Adam D. Ruppe
http://arsdnet.net
Jul 29 2009