On Wed, 12 Feb 2014 21:01:58 -0000, Jesse Phillips
<jesse.k.phillip...@gmail.com> wrote:
On Wednesday, 12 February 2014 at 10:52:13 UTC, Regan Heath wrote:
On Tue, 11 Feb 2014 19:48:40 -0000, Jesse Phillips
<jesse.k.phillip...@gmail.com> wrote:
On Tuesday, 11 February 2014 at 10:10:27 UTC, Regan Heath wrote:
Things like this should "just work"..
File input ...
auto range = input.byLine();
while(!range.empty)
{
range.popFront();
foreach (i, line; range.take(4)) //Error: cannot infer argument
types
{
It isn't *required* to (input/forward), but it could (random access).
I think we even have a template to test if it's indexable as we can
optimise some algorithms based on this.
You chopped of your own comment prompting this response, in which I am
responding to a minor side-point, which I think has confused the actual
issue. All I was saying above was that a range might well have an index,
and we can test for that, but it's not relevant to the foreach issue below.
What do you expect 'i' to be? Is it the line number? Is it the index
within the line where 'take' begins? Where 'take' stops?
If I say take(5) I expect 0,1,2,3,4. The index into the take range
itself.
I don't see how these two replies can coexist. 'range.take(5)' is a
different range from 'range.'
Yes, exactly, meaning that it can trivially "count" the items it returns,
starting from 0, and give those to me as 'i'. *That's all I want*
'range may not traverse in index order (personally haven't seen such a
range). But more importantly you're not dealing with random access
ranges. The index you're receiving from take(5) can't be used on the
range.
A forward range can do what I am describing above, it's trivial.
Don't get me wrong, counting the elements as you iterate over them is
useful, but it isn't the index into the range you're likely after.
Nope, not what I am after. If I was, I'd iterate over the original range
instead or keep a line count manually.
Maybe the number is needed to correspond to a line number.
Nope. The file contains records of 5 lines plus a blank line. I want 0,
1, 2, 3, 4, 5 so I can skip lines 0, 2, and 5 *of each record*.
R
--
Using Opera's revolutionary email client: http://www.opera.com/mail/
