how to get line number after readln

[Brad Anderson via Digitalmars-d-learn]

On Thursday, 5 June 2014 at 00:33:26 UTC, Ali Çehreli wrote:
> On 06/04/2014 05:05 PM, Robert Hathaway wrote:
>> I've got a program that reads a text file line by line (using 
>> std.stdio
>> readln())
>
> Consider using byLine() instead. (Important: byLine uses an 
> internal buffer for the line; so, don't forget to make a copy 
> if you want to store the line for later use.)
>
> > and I'd like to refer to the line number when I send a message
>> to stderr upon finding a mis-formatted line.  Is there a way 
>> to get the
>> current line number?  Of course, I could create a counter and 
>> increment
>> it with each call to readln, but is there a "cool" way of 
>> doing this?
>>
>> Okay, call me lazy... just don't call me late for dinner! :-)
>>
>> Robert
>
> One cool way is a zipped sequence:
>
> import std.stdio;
> import std.range;
>
> void main()
> {
>     foreach (i, line; zip(sequence!"n", 
> File("deneme.txt").byLine)) {
>         writefln("%s: %s", i, line);
>     }
> }
>
> Ali

Once this[1] gets merged you'll be able to do this:

foreach (lineNum, line; File("deneme.txt").byLine().enumerate(1))
       writefln("%s: %s", lineNum, line);

Which is a bit more clear about the intent.

1. https://github.com/D-Programming-Language/phobos/pull/1866