[GAP Forum] Lexical closures

[Stephen Linton]

This seems rather complicated compared to

MakeF2 := function(q)
	return x-> x+q:
end;

Then you can use 

f0 := MakeF2(10);
f1 := MakeF2(20);

Does this do what you need?

	Steve

On 16 Apr 2015, at 23:19, Luca Giuzzi <luca.giuzzi at gmail.com> wrote:
> 
> Dear Forum,
> is there a canonical way in gap to generate lexical closures for functions?
> The best I could come up with is something like
> 
> MakeF:=function ()
>    local  q;
>    q := ValueGlobal( "q" );
>    return function(x)
>       return x+q;
>    end;
> end;
> 
> which captures the value of the global value of q, so that
> q:=10; f0:=MakeF();
> q:=20  f1:=MakeF();
> gives
> f0(0)=10 and f1(0)=20
> and it "sort of works" (and, at least for the cases I have in mind it
> might be enough)
> Still, I am asking if there might a better (or canonical) way to implement this?
> 
> Regards,
> luca
> 
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