On Tue, 13 Jul 2010 08:54:07 -0400, Michel Fortin
<[email protected]> wrote:
On 2010-07-13 00:38:55 -0400, Andrei Alexandrescu
<[email protected]> said:
Yah, truth be told getNext won't win a prize for brevity. You need to
define both a variable and a pointer to use it:
T meh;
T * neh;
while ((neh = getNext(r, meh))) {
... process *neh ...
}
At this point what you want is to use a foreach loop. In fact, if
foreach could be made to work with getNext (and it should), you'd rarely
need to write that boilerplate code yourself.
struct InputForeach(R) if(isInputRangeThatUsesGetNext!R)
{
private R* range;
this(ref R range) {this.range = ⦥}
int opApply(scope int delegate(ref ElementType!R) dg)
{
ElementType!R buf;
ElementType!R *e;
int result = 0;
while(!result && (e = getNext(*range, buf)))
{
result = dg(*e);
}
return result;
}
}
InputForeach!R inputForeach(R)(ref R r) if(isInputRangeThatUsesGetNext!R)
{ return InputForeach!R(r); }
foreach(e; inputForeach(r))
{
...
}
opApply to the rescue :)
Of course, native support would be better, unless the compiler decides to
start inlining opApply.
-Steve
