Am 04.03.2013 13:23, schrieb Michael Van Canneyt:
On Mon, 4 Mar 2013, Mattias Gaertner wrote:
On Mon, 04 Mar 2013 11:17:53 +0000
Martin <laza...@mfriebe.de> wrote:
On 04/03/2013 04:54, Boian Mitov wrote:
Here is example:
Parallel execution with selection of executor:
for i := 0 to AMaxScaleIndex - 1 do
begin
APerIterationLocations.Add( TRTDynamicList<TVLImageRect>.Create() );
AExecutionTask.Add( AExecutor.Execute(
procedure()
begin
ProcessOne( levelScale[ i ], img, hitThreshold, winStride,
padding, APerIterationLocations[ i ] );
end
));
end;
In this case, not only you save declaration, you save the need to
write a whole new class just for the task.
This code reduced well over 30 lines of code alone.
I have a lot of other examples as well ;-) .
Ok, I can see the closure helping, but why the anonymous procedure?
If FPC would offer something like this:
Procedure Foo;
var
// your locals
procedure Bar(); closure;
begin
ProcessOne( levelScale[ i ], img, hitThreshold, winStride,
padding, APerIterationLocations[ i ] );
end
begin
// your code from above
for i := 0 to AMaxScaleIndex - 1 do
begin
APerIterationLocations.Add(
TRTDynamicList<TVLImageRect>.Create() );
AExecutionTask.Add( AExecutor.Execute( @Bar ));
end;
I added:
- the name "Bar"
- Used is at reference
- the keyword "closure"
The above code would then create the exact same closure, as your code
does. And it does not need an anonymous method.
Nice. Gimme, gimme.
IMHO this is a pefectly acceptable solution. Adds only a modifier
(modifiers are not keywords) and offers all advantages of closures.
No need for 'anonymous' procedures, which are very unpascal-ish.
People who want that should not be using Pascal to begin with.
If you guys would read what I wrote in one of my first answers to
Vasiliy in this thread than you would know that I want him to implement
this possiblity as well... but after all, who reads the mails of some
strange computer science student who just happens to work on the
compiler -.-
To rephrase: implement support for anonymous functions for Delphi
compatibility (maybe coupled to a mode switch) and allow for all other
modes the assignment of nested functions/procedures to "reference to"
procvars instead. Additionally a shortened "lambda syntax" can be added
for really simple cases.
Regards,
Sven
_______________________________________________
fpc-devel maillist - fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel
