http://d.puremagic.com/issues/show_bug.cgi?id=2081

           Summary: Foreach over Stream appears broken
           Product: D
           Version: 2.012
          Platform: PC
        OS/Version: Linux
            Status: NEW
          Severity: normal
          Priority: P2
         Component: Phobos
        AssignedTo: bugzilla@digitalmars.com
        ReportedBy: jlquinn@optonline.net


I'm trying to use the foreach idiom shown in the docs for InputStream, but the compiler rejects my code.  The program is:

import std.cstream;
import std.stream;

void test() {
  string file = "test";
  Stream f = new BufferedFile(file);

  foreach (ulong line, string buf; f) {
    derr.writefln(buf);
  }
}

The compiler complains:

dmd/bin/dmd junk2.d
junk2.d(8): function std.stream.Stream.opApply (int delegate(ref char[] line))
does not match parameter types (int delegate(ref ulong __applyArg0, ref
invariant(char)[] __applyArg1))
junk2.d(8): Error: cannot implicitly convert expression (__foreachbody15) of
type int delegate(ref ulong __applyArg0, ref invariant(char)[] __applyArg1) to
int delegate(ref ulong n, ref wchar[] line)


-- 

http://d.puremagic.com/issues/show_bug.cgi?id=2081


shro8822@vandals.uidaho.edu changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |enhancement




------- Comment #1 from shro8822@vandals.uidaho.edu  2008-05-08 17:09 -------
try this

foreach (ref string buf; f)

there isn't a opApply with an index value, But IMHO there should be

(converting to feature request)


-- 

http://d.puremagic.com/issues/show_bug.cgi?id=2081


jlquinn@optonline.net changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|enhancement                 |normal




------- Comment #2 from jlquinn@optonline.net  2008-05-08 17:18 -------
The code becomes:

    foreach (ref string buf; f) {

which the compiler still dislikes:

lexicon.d(92): function std.stream.Stream.opApply (int delegate(ref char[]
line)) does not match parameter types (int delegate(ref invariant(char)[] buf))
lexicon.d(92): Error: cannot implicitly convert expression (__foreachbody15) of
type int delegate(ref invariant(char)[] buf) to int delegate(ref ulong n, ref
wchar[] line)

Changing back to a bug :-)

 BTW, why is "ref" needed?  If so, the docs aren't clear about that and need to
be updated.


-- 

http://d.puremagic.com/issues/show_bug.cgi?id=2081





------- Comment #3 from shro8822@vandals.uidaho.edu  2008-05-08 17:34 -------
If it's a bug, than it's a bug in DMD. If it's related to phobos than it's a feature request because it's operating correctly, just not the way we want it to.


I use D1.0 so I can't test it but try this

foreach (ref char[] buf; f) {


-- 

http://d.puremagic.com/issues/show_bug.cgi?id=2081





------- Comment #4 from jlquinn@optonline.net  2008-05-08 20:28 -------
(In reply to comment #3)
> If it's a bug, than it's a bug in DMD. If it's related to phobos than it's a feature request because it's operating correctly, just not the way we want it to.

Well, the docs say it should work, so there is at least the bug that the docs don't align with the implementation, even if we accept the implementation as correct.

> I use D1.0 so I can't test it but try this
> 
> foreach (ref char[] buf; f) {

I expect that should work, but I'm trying to use string where I can.  I tend to find string as a type more aesthetically pleasing to work with.


-- 

http://d.puremagic.com/issues/show_bug.cgi?id=2081


Witold Baryluk <baryluk@smp.if.uj.edu.pl> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |baryluk@smp.if.uj.edu.pl


--- Comment #5 from Witold Baryluk <baryluk@smp.if.uj.edu.pl> 2010-11-24 07:44:01 PST ---
I just hit this bug.

What is worse, example on page http://digitalmars.com/d/2.0/phobos/std_stream.html#opApply do not work exactly because of this bug!

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