Function calls

[torhu]

On 29.01.2010 05:20, Steven Schveighoffer wrote:
> Andrei Alexandrescu Wrote:
>
>>  Michiel Helvensteijn wrote:
>>  >  Andrei Alexandrescu wrote:
>>  >
>>  >>>>  foreach (line; stdin.byLine()) { ... }
>>  >>>>
>>  >>>>  vs.
>>  >>>>
>>  >>>>  foreach (line; stdin.byLine) { ... }
>>  >>>>
>>  >>>>  How do I choose?
>>  >>>  byLine is a property.  It is fetching a range on stdin.
>>  >>>
>>  >>>  -Steve
>>  >>  Damn. I was sure the answer will be different.
>>  >
>>  >  byLine() is a function. It changes the state of stdin. Calling it
>>  >  consecutively will in general result in different return values. If there
>>  >  were two guys: stdin.currentLine (property) and stdin.nextLine(), it would
>>  >  be a different story.
>
> No no no.  byLine returns a struct, it does not modify stdin.  Operating on the struct modifies stdin, but that is outside the call to the property getter.
>
> Look at it this way (although this is not the only way to look at it), could byLine be a field inside stdin?  It could.  You could store a copy of what byLine returns inside stdin, and people could just access it.

Before more time is wasted in this discussion, I would like to point out 
that byLine does actually have two arguments.  I wrote a post about 
byLine yesterday, but noone seems to have noticed..