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digitalmars.D - Foreach, return not exist the function.

reply "Zaher Dirkey" <zaherdirkey yahoo.com> writes:
First time i used foreach with opApply in my classed, and i got 
this strange behavior.

return e, not exit the function "findClass"
i tried to reproduce it, but it is worked in reproduce example.
but you can read it and read the result of writeln.
I still feel it is my eyes or a small mistake.

---------------------
SrdController findClass(const ClassInfo controllerClass)
{
	foreach(e; this) {
		if (e.classinfo.name == controllerClass.name) {
			writeln("we found " ~ e.classinfo.name);
			return e;
		}
	}
	writeln("not found ");
	return null;
}

results
------------------

sard.parsers.SrdControllers.add(sard.parsers.SrdControllerNormal)
sard.parsers.SrdControllers.add(sard.parsers.SrdControllerDefines)
we found sard.parsers.SrdControllerNormal
not found

reproduce example here
http://dpaste.dzfl.pl/13fb453d0b1e


it is part for opensource code here
https://github.com/parmaja/sard/blob/master/src/sard/parsers.d#L222
Jan 11 2015
parent reply =?UTF-8?B?QWxpIMOHZWhyZWxp?= <acehreli yahoo.com> writes:
On 01/11/2015 12:25 PM, Zaher Dirkey wrote:


 reproduce example here
 http://dpaste.dzfl.pl/13fb453d0b1e


That link doesn't work for me. (?)

Does opApply return the delegate's return value ('b' below)?

import std.stdio;

struct S
{
     int opApply(int delegate(int) dg)
     {
         foreach (i; 0 .. 10) {
             int b = dg(i);
             if (b) {
                 writefln("Exiting opApply with %s", b);
                 return b;
             }
         }

         return 0;
     }
}

int foo()
{
     auto s = S();
     foreach (i; s) {
         writeln(i);
         return 42;
     }

     return 0;
}

void main()
{
     assert(foo() == 42);
}

Ali
Jan 11 2015
next sibling parent "Zaher Dirkey" <zaherdirkey yahoo.com> writes:
On Sunday, 11 January 2015 at 23:50:18 UTC, Ali Çehreli wrote:

 On 01/11/2015 12:25 PM, Zaher Dirkey wrote:


 reproduce example here
 http://dpaste.dzfl.pl/13fb453d0b1e


 That link doesn't work for me. (?)

 Does opApply return the delegate's return value ('b' below)?


It must return object, but it is in template
i added ref, or witout ref, same
this the part of opApply

int opApply(int delegate(ref T) callback)
{
    int result = 0;
    for (int i = 0; i < _items.length; ++i)
    {
       result = callback(_items[i]);
       if (result == 0)
       break;
    }
    return result;
}

this part code here 
https://github.com/parmaja/sard/blob/master/src/sard/classes.d


and reproduced (but works fine) here

https://github.com/zaher/d_test/blob/master/foreach.d
Jan 11 2015
prev sibling parent "Zaher Dirkey" <zaherdirkey yahoo.com> writes:
On Sunday, 11 January 2015 at 23:50:18 UTC, Ali Çehreli wrote:

 On 01/11/2015 12:25 PM, Zaher Dirkey wrote:


 reproduce example here
 http://dpaste.dzfl.pl/13fb453d0b1e


 That link doesn't work for me. (?)

 Does opApply return the delegate's return value ('b' below)?

 import std.stdio;

 struct S
 {
     int opApply(int delegate(int) dg)
     {
         foreach (i; 0 .. 10) {
             int b = dg(i);
             if (b) {
                 writefln("Exiting opApply with %s", b);
                 return b;
             }
         }

         return 0;
     }
 }

 int foo()
 {
     auto s = S();
     foreach (i; s) {
         writeln(i);
         return 42;
     }

     return 0;
 }

 void main()
 {
     assert(foo() == 42);
 }

 Ali


It in breaking the loop in opApply

    if (result==0) {
must be
   if (result) {

Thanks to Ali, and Zor at #D (freenode)
Jan 12 2015