Re: Foreach problem
On Tue, Jan 13, 2009 at 6:25 AM, Steven Schveighoffer schvei...@yahoo.com wrote: because that's basically what a foreach does when using opApply: create an inner function and then pass a delegate pointing to that function to opApply. I think the difference between the two is that the compiler handles foreach on an array in a special manner without using an inner function/delegate. That's an implementation detail and shouldn't effect the behavior visible to the user. --bb
Re: Foreach problem
On Sun, 11 Jan 2009 20:31:51 +1300, Denis Koroskin 2kor...@gmail.com wrote: Yep that probibly is a slight bug. What I would like to know is why cant I do foreach with primitive types like I can with objects. You can use foreach to iterate over arrays and tuples, if that's what you mean. Iterating over over primitive types makes little sense. Just re reading my own question I think it is clear what I meant. I meant array of primitives so yes iterating over an array, but an array of primitives. Dmd handles foreach over SomeObject[] a lot more relaxed than int[].
Foreach problem
Why is this an error. Dmd wants to make sure that I declare a new variable
in the foreach statement and not use an existing one?
module test;
void main()
{
int i;
int[] nums;
foreach(i; nums)
{
//
}
}
dmd test.d
test.d(7): Error: shadowing declaration test.main.i is deprecated
Re: Foreach problem
Tim M wrote:
Why is this an error. Dmd wants to make sure that I declare a new
variable in the foreach statement and not use an existing one?
module test;
void main()
{
int i;
int[] nums;
foreach(i; nums)
{
//
}
}
dmd test.d
test.d(7): Error: shadowing declaration test.main.i is deprecated
Yes; as the error states, you're not allowed to define variables with
the same name as variables in an enclosing scope any more.
-- Daniel
Re: Foreach problem
On Sun, 11 Jan 2009 15:50:54 +1300, Daniel Keep
daniel.keep.li...@gmail.com wrote:
Tim M wrote:
Why is this an error. Dmd wants to make sure that I declare a new
variable in the foreach statement and not use an existing one?
module test;
void main()
{
int i;
int[] nums;
foreach(i; nums)
{
//
}
}
dmd test.d
test.d(7): Error: shadowing declaration test.main.i is deprecated
Yes; as the error states, you're not allowed to define variables with
the same name as variables in an enclosing scope any more.
-- Daniel
Why does it still work for some objects?
Re: Foreach problem
On Sun, 11 Jan 2009 15:59:26 +1300, Tim M a...@b.com wrote:
On Sun, 11 Jan 2009 15:50:54 +1300, Daniel Keep
daniel.keep.li...@gmail.com wrote:
Tim M wrote:
Why is this an error. Dmd wants to make sure that I declare a new
variable in the foreach statement and not use an existing one?
module test;
void main()
{
int i;
int[] nums;
foreach(i; nums)
{
//
}
}
dmd test.d
test.d(7): Error: shadowing declaration test.main.i is deprecated
Yes; as the error states, you're not allowed to define variables with
the same name as variables in an enclosing scope any more.
-- Daniel
Why does it still work for some objects?
This works:
module test;
class A
{
this()
{
//
}
}
class B
{
this()
{
//
}
int opApply (int delegate (inout B) dg)
{
return 1;
}
}
void main()
{
A a;
B b;
foreach(a; b)
{
//
}
}
Re: Foreach problem
On Sun, Jan 11, 2009 at 12:04 PM, Tim M a...@b.com wrote:
On Sun, 11 Jan 2009 15:59:26 +1300, Tim M a...@b.com wrote:
Why does it still work for some objects?
This works:
module test;
class A
{
this()
{
//
}
}
class B
{
this()
{
//
}
int opApply (int delegate (inout B) dg)
{
return 1;
}
}
void main()
{
A a;
B b;
foreach(a; b)
{
//
}
}
Interesting. But there the inner 'a' is actually a B. So it
compiles, but there's no way it's using the outer 'a' as the counter
variable.
--bb
Re: Foreach problem
On Sun, 11 Jan 2009 16:10:39 +1300, Bill Baxter wbax...@gmail.com wrote:
On Sun, Jan 11, 2009 at 12:04 PM, Tim M a...@b.com wrote:
On Sun, 11 Jan 2009 15:59:26 +1300, Tim M a...@b.com wrote:
Why does it still work for some objects?
This works:
module test;
class A
{
this()
{
//
}
}
class B
{
this()
{
//
}
int opApply (int delegate (inout B) dg)
{
return 1;
}
}
void main()
{
A a;
B b;
foreach(a; b)
{
//
}
}
Interesting. But there the inner 'a' is actually a B. So it
compiles, but there's no way it's using the outer 'a' as the counter
variable.
--bb
Sorry for my typo but change that line to:
int opApply (int delegate (inout A) dg)
and it still compiles.
Re: Foreach problem
On Sun, Jan 11, 2009 at 12:15 PM, Tim M a...@b.com wrote:
On Sun, 11 Jan 2009 16:10:39 +1300, Bill Baxter wbax...@gmail.com wrote:
On Sun, Jan 11, 2009 at 12:04 PM, Tim M a...@b.com wrote:
On Sun, 11 Jan 2009 15:59:26 +1300, Tim M a...@b.com wrote:
Why does it still work for some objects?
This works:
module test;
class A
{
this()
{
//
}
}
class B
{
this()
{
//
}
int opApply (int delegate (inout B) dg)
{
return 1;
}
}
void main()
{
A a;
B b;
foreach(a; b)
{
//
}
}
Interesting. But there the inner 'a' is actually a B. So it
compiles, but there's no way it's using the outer 'a' as the counter
variable.
--bb
Sorry for my typo but change that line to:
int opApply (int delegate (inout A) dg)
and it still compiles.
'Still compiles or then it will compile?
Anyway, I'm curious if it's using the outer A or not. Can you add a
line or two to actually modify 'a' in the loop?
--bb
Re: Foreach problem
On Sun, 11 Jan 2009 06:04:01 +0300, Tim M a...@b.com wrote:
On Sun, 11 Jan 2009 15:59:26 +1300, Tim M a...@b.com wrote:
On Sun, 11 Jan 2009 15:50:54 +1300, Daniel Keep
daniel.keep.li...@gmail.com wrote:
Tim M wrote:
Why is this an error. Dmd wants to make sure that I declare a new
variable in the foreach statement and not use an existing one?
module test;
void main()
{
int i;
int[] nums;
foreach(i; nums)
{
//
}
}
dmd test.d
test.d(7): Error: shadowing declaration test.main.i is deprecated
Yes; as the error states, you're not allowed to define variables with
the same name as variables in an enclosing scope any more.
-- Daniel
Why does it still work for some objects?
This works:
module test;
class A
{
this()
{
//
}
}
class B
{
this()
{
//
}
int opApply (int delegate (inout B) dg)
{
return 1;
}
}
void main()
{
A a;
B b;
foreach(a; b)
{
//
}
}
It is a bug and should be reported.
