• BCS (24/24) Aug 19 2006 from: http://www.digitalmars.com/d/statement.html#foreach
• Oskar Linde (6/38) Aug 19 2006 Why? How would you then handle more than two variable foreach loops?
• BCS (7/45) Aug 19 2006 I known of nowhere that says that anthing but the 1 and 2 argument forms...
• Oskar Linde (7/56) Aug 20 2006 It tells you exactly what was wrong to the compiler. It didn't find a wa...

BCS <BCS pathlink.com> writes:

from: http://www.digitalmars.com/d/statement.html#foreach

<bnf>
ForeachStatement:
	foreach (ForeachTypeList; Expression) Statement

ForeachTypeList:
	ForeachType
	ForeachType , ForeachTypeList
</bnf>

Based on this the following is syntacticly correct.

void main()
{
char[] foo;
foreach(i,j,k;foo)
{}
}

In fact it gives the error

    foreach.d(5): cannot infer type for j

which tells you nothing of much use. The following syntax looks more 
reasonable to me.

<bnf>
ForeachTypeList:
	ForeachType
	ForeachType , ForeachType
</bnf>

Oskar Linde <olREM OVEnada.kth.se> writes:

BCS wrote:

 from: http://www.digitalmars.com/d/statement.html#foreach
 
 <bnf>
 ForeachStatement:
 foreach (ForeachTypeList; Expression) Statement
 
 ForeachTypeList:
 ForeachType
 ForeachType , ForeachTypeList
 </bnf>
 
 Based on this the following is syntacticly correct.
 
 void main()
 {
 char[] foo;
 foreach(i,j,k;foo)
 {}
 }
 
 In fact it gives the error
 
     foreach.d(5): cannot infer type for j

Which is a correct error message.

 
 which tells you nothing of much use. The following syntax looks more
 reasonable to me.
 
 <bnf>
 ForeachTypeList:
 ForeachType
 ForeachType , ForeachType
 </bnf>

Why? How would you then handle more than two variable foreach loops?
foreach(i,j,k,l,m;foo) is a valid syntax given a foo with an opApply taking
a 5 argument delegate.

/Oskar

BCS <foobar pathlink.net> writes:

Oskar Linde wrote:
 BCS wrote:
 from: http://www.digitalmars.com/d/statement.html#foreach

 <bnf>
 ForeachStatement:
 foreach (ForeachTypeList; Expression) Statement

 ForeachTypeList:
 ForeachType
 ForeachType , ForeachTypeList
 </bnf>

 Based on this the following is syntacticly correct.

 void main()
 {
 char[] foo;
 foreach(i,j,k;foo)
 {}
 }

 In fact it gives the error

     foreach.d(5): cannot infer type for j

 Which is a correct error message.

but it tells you nothing about what is wrong.

 which tells you nothing of much use. The following syntax looks
 more reasonable to me.

 <bnf>
 ForeachTypeList:
 ForeachType
 ForeachType , ForeachType
 </bnf>

 Why? How would you then handle more than two variable foreach loops?
 foreach(i,j,k,l,m;foo) is a valid syntax given a foo with an opApply
 taking a 5 argument delegate.
 /Oskar

I known of nowhere that says that anthing but the 1 and 2 argument forms of the
opApply are even valid. I haven't tried it though. Looking at the sepc, it looks
like it might be allowed, but it dosn't actualy say so.

Whatever the case, the docs need a little work here and the error message gives
nothing usefull other than the line number

Oskar Linde <olREM OVEnada.kth.se> writes:

BCS wrote:

 Oskar Linde wrote:
 BCS wrote:
 from: http://www.digitalmars.com/d/statement.html#foreach

 <bnf>
 ForeachStatement:
 foreach (ForeachTypeList; Expression) Statement

 ForeachTypeList:
 ForeachType
 ForeachType , ForeachTypeList
 </bnf>

 Based on this the following is syntacticly correct.

 void main()
 {
 char[] foo;
 foreach(i,j,k;foo)
 {}
 }

 In fact it gives the error

     foreach.d(5): cannot infer type for j

 Which is a correct error message.

 
 but it tells you nothing about what is wrong.

It tells you exactly what was wrong to the compiler. It didn't find a way to
infer the type for j. Such error messages are often better than if the
compiler tries to guess what you intended.

 
 which tells you nothing of much use. The following syntax looks
 more reasonable to me.

 <bnf>
 ForeachTypeList:
 ForeachType
 ForeachType , ForeachType
 </bnf>

 Why? How would you then handle more than two variable foreach loops?
 foreach(i,j,k,l,m;foo) is a valid syntax given a foo with an opApply
 taking a 5 argument delegate.
 /Oskar

 
 I known of nowhere that says that anthing but the 1 and 2 argument forms
 of the opApply are even valid. I haven't tried it though. Looking at the
 sepc, it looks like it might be allowed, but it dosn't actualy say so.

It is allowed and works very well.

 
 Whatever the case, the docs need a little work here and the error message
 gives nothing usefull other than the line number

The correct file? The correct line number? And you are still complaining? ;) 

/Oskar