• Meta (14/14) Jan 24 2015 import std.stdio;
• =?UTF-8?B?QWxpIMOHZWhyZWxp?= (23/37) Jan 24 2015 Unless the range itself provides explicitly, automatic counter is
• Meta (3/12) Jan 24 2015 Hmm, how have I not known that until now? I thought that feature
• Steven Schveighoffer (8/21) Jan 26 2015 It would be confusing. Imagine this scenario:

"Meta" <jared771 gmail.com> writes:

import std.stdio;

void main()
{
     foreach (i, line; file.byLine())
     {
         writeln(line);
     }
}

This code gives me the error:

Error: cannot infer argument types, expected 1 argument, not 2

This is a very obtuse compiler message considering how simple the 
code is; I know it's got something to do with the foreach 
statement and what byLine() returns, but I can't seem to get it 
to compile without removing `i`.

=?UTF-8?B?QWxpIMOHZWhyZWxp?= <acehreli yahoo.com> writes:

On 01/24/2015 12:14 AM, Meta wrote:

 import std.stdio;

 void main()
 {
      foreach (i, line; file.byLine())

Unless the range itself provides explicitly, automatic counter is 
available only for arrays. Otherwise, you have to enumerate yourself. ;)

import std.stdio;
import std.range;

void main()
{
     foreach (i, element; iota(42, 45).enumerate) {
         writefln("%s: %s", i, element);
     }
}

I am not sure whether std.range.enumerate is available in the current 
compiler. If not, you can use zip and sequence:

     foreach (i, element; zip(sequence!"n", iota(42, 45))) {
         writefln("%s: %s", i, element);
     }

However, that code is taking advantage of automatic tuple expansion, 
which causes trouble in some cases but not here. If you don't want that, 
you can expand the tuple explicitly:

     foreach (t; zip(sequence!"n", iota(42, 45))) {
         writefln("%s: %s", t[0], t[1]);
     }

      {
          writeln(line);
      }
 }

 This code gives me the error:

 Error: cannot infer argument types, expected 1 argument, not 2

 This is a very obtuse compiler message considering how simple the code
 is; I know it's got something to do with the foreach statement and what
 byLine() returns, but I can't seem to get it to compile without removing
 `i`.

Ali

"Meta" <jared771 gmail.com> writes:

On Saturday, 24 January 2015 at 08:44:45 UTC, Ali Çehreli wrote:
 On 01/24/2015 12:14 AM, Meta wrote:

 import std.stdio;

 void main()
 {
      foreach (i, line; file.byLine())

 Unless the range itself provides explicitly, automatic counter 
 is available only for arrays. Otherwise, you have to enumerate 
 yourself. ;)

Hmm, how have I not known that until now? I thought that feature 
worked for all ranges. Thanks.

Steven Schveighoffer <schveiguy yahoo.com> writes:

On 1/24/15 11:15 AM, Meta wrote:
 On Saturday, 24 January 2015 at 08:44:45 UTC, Ali Çehreli wrote:
 On 01/24/2015 12:14 AM, Meta wrote:

 import std.stdio;

 void main()
 {
      foreach (i, line; file.byLine())

 Unless the range itself provides explicitly, automatic counter is
 available only for arrays. Otherwise, you have to enumerate yourself. ;)

 Hmm, how have I not known that until now? I thought that feature worked
 for all ranges. Thanks.

It would be confusing. Imagine this scenario:

auto l = file.byLine();
l.popFront();

foreach(i, line; l)

Now, the line numbers are off by one, because the ByLine struct does not 
track them.

-Steve