Why does readln include the line terminator?

[Daniel Keep]

Andrei Alexandrescu wrote:
> Daniel Keep wrote:
>>
>> Andrei Alexandrescu wrote:
>>> ...
>>>
>>> Right now readln preserves the separator. The newer File.byLine
>>> eliminates it by default and offers to keep it by calling
>>> File.byLine(KeepTerminator.yes). The allowed terminators are one
>>> character or a string. See
>>>
>>> http://erdani.dreamhosters.com/d/web/phobos/std_stdio.html#byLine
>>>
>>> I consider such an API adequate but insufficient; we need to add to it.
>>>
>>>
>>> Andrei
>>
>> Why not:
>>
>> char[] line, sep;
>> line = File.byLine();    // discard sep
>> line = File.byLine(sep); // pass sep out
>>
>> The separator is likely to be more useful once extracted.
> 
> And how about when sep is elaborate (e.g. regex)?
> 
> Andrei

Whatever was matched.  If we have a file containing:

"A.B,C"

And we split lines using /[.,]/, then this:

> char[] line, sep;
> line = File.byLine(sep);
> while( line != "" )
> {
>     writefln(`line = "%s", sep = "%s"`, line, sep);
>     line = File.byLine(sep);
> }

Would output this:

> line = "A", sep = "."
> line = "B", sep = ","
> line = "C", sep = ""

  -- Daniel