So, I wanted to wrap my head a little tighter around those strange animals that are lamdas.

I wrote the simpliest program utilizing a lambda :

import std.stdio;
void main(){
	writeln({return "foobar";});
}

and it yields 43106C, which does not look like "foobar" at all, but rather, I suspect, like a pointer or something.
So I tried
       writeln(typeid({return "foobar";}));
which in turn yelds immutable(char)[]()*
that hints further to a pointer.
I get the immutable(char)[] : an immutable array of characters, why not. But I really don"t get the set of parens between the square brackets and the asterisk. Could that mean that what I get is in fact a pointer to a function ? (said function having no arguments, or having void as sole argument or ...)

Now, the question (and the very point of a lambda if I get it right) would be to get this function to evaluate (and precisely return the string "foobar" in this example).

What syntactic subtility am I missing ?

On Sunday, 27 October 2013 at 14:01:31 UTC, Derix wrote:
> So, I wanted to wrap my head a little tighter around those strange animals that are lamdas.
>
> I wrote the simpliest program utilizing a lambda :
>
> import std.stdio;
> void main(){
> 	writeln({return "foobar";});
> }
>

You still have to call the lambda just like a function, with ():

import std.stdio;
void main() {
	writeln({return "foobar";}());
}

On Sunday, 27 October 2013 at 14:10:50 UTC, Maurice wrote:
> On Sunday, 27 October 2013 at 14:01:31 UTC, Derix wrote:
>> So, I wanted to wrap my head a little tighter around those strange animals that are lamdas.
>>
>> I wrote the simpliest program utilizing a lambda :
>>
>> import std.stdio;
>> void main(){
>> 	writeln({return "foobar";});
>> }
>>
>
> You still have to call the lambda just like a function, with ():
>
> import std.stdio;
> void main() {
> 	writeln({return "foobar";}());
> }

Some clarification:

import std.stdio;
void main() {
    auto f = {return "foobar";}; // f behaves like a function.
    auto s = f(); // it can be called like any other function, it takes no parameters.
    writeln(s);
}

On Sunday, 27 October 2013 at 14:01:31 UTC, Derix wrote:
> I get the immutable(char)[] : an immutable array of characters, why not. But I really don"t get the set of parens between the square brackets and the asterisk. Could that mean that what I get is in fact a pointer to a function ? (said function having no arguments, or having void as sole argument or ...)

Yes, this is correct.

You still have to call the lambda: { return 42; }().

David