Hi,
the confusion starts here: http://dlang.org/function.html#closures
End of paragraph bellow the last delegate example:
"This combining of the environment and the function is called a dynamic closure."

While according to https://en.wikipedia.org/wiki/Scope_%28computer_science%29
"Lexical scope vs. dynamic scope" I would call D delegates lexical closures, as the scope of the callee (scope where callee is defined) is used for free variable lookup, isn't that right?

Confusion is enhanced with this Dlang wiki: http://wiki.dlang.org/Function_literals
"This has brought up the specter of Dynamic Closures. The nested and/or anonymous functions can only access dynamic scope, which means scope that exists on the stack at the time of execution. This differs from lexical scope, which refers to the scope as indicated by the program text structure."

So what's what now?

Cheers, ParticlePeter

On Sunday, 8 November 2015 at 23:08:05 UTC, ParticlePeter wrote:
> Hi,
> the confusion starts here: http://dlang.org/function.html#closures
> End of paragraph bellow the last delegate example:
> "This combining of the environment and the function is called a dynamic closure."
>
> While according to https://en.wikipedia.org/wiki/Scope_%28computer_science%29
> "Lexical scope vs. dynamic scope" I would call D delegates lexical closures, as the scope of the callee (scope where callee is defined) is used for free variable lookup, isn't that right?
>
> Confusion is enhanced with this Dlang wiki: http://wiki.dlang.org/Function_literals
> "This has brought up the specter of Dynamic Closures. The nested and/or anonymous functions can only access dynamic scope, which means scope that exists on the stack at the time of execution. This differs from lexical scope, which refers to the scope as indicated by the program text structure."
>
> So what's what now?
>
> Cheers, ParticlePeter

The closures for delegates in D1 are never automatically copied to the heap, while in D2 this is done when it's determined that the delegate might outlive one of its upvalues.

So, I think it's safe to say we have lexical closures in D2 but only dynamic closures in D1 and the language specification is out of date.

On Sunday, 8 November 2015 at 23:17:06 UTC, Jakob Ovrum wrote:
> The closures for delegates in D1 are never automatically copied to the heap, while in D2 this is done when it's determined that the delegate might outlive one of its upvalues.
>
> So, I think it's safe to say we have lexical closures in D2 but only dynamic closures in D1 and the language specification is out of date.

Thanks, makes sens, I assumed a typo in the docs.