Full closures for D

[Bill Baxter]

Witold Baryluk wrote:
> Dnia Tue, 06 Nov 2007 20:17:58 -0700
> Russell Lewis <webmaster at villagersonline.com> napisał/a:
> 
>> Or even:
>>
>> C delegate(B) curry(A, C, B...)(C delegate(A, B) dg_, A a_) {
>>    return delegate C(B b) { return dg_(a_, b); };
>> }
> 
> Yes i was thinking about it, but didn't know if it should work.
> I just installed 2.007, and it is working! :)
> 
> 
> import std.stdio;
> 
> C delegate(B) curry1(A, C, B...)(C delegate(A, B) dg_, A a_) {
>         auto a = a_;
>         auto dg = dg_;
>         C add(B b) {
>                 return dg(a, b);
>         }
>         return &add;
> }
> 
> C delegate(B) curry2(A, C, B...)(C delegate(A, B) dg, A a) {
>         C add(B b) {
>                 return dg(a, b);
>         }
>         return &add;
> }
> 
> C delegate(B) curry3(A, C, B...)(C delegate(A, B) dg, A a) {
>         return delegate C(B b) { return dg(a, b); };
> }
> 
> 
> 
> int main(char[][] args) {
>         int sum(int a, int b, int c) {
>                 return a+b+c;
>         }
> 
>         auto s1 = curry1(&sum, 11000);
>         assert(s1(200,30) == 11230);
> 
>         auto s2 = curry2(&sum, 21000);
>         assert(s2(200,30) == 21230);
> 
>         auto s3 = curry3(&sum, 31000);
>         assert(s3(200,30) == 31230);
> 
>         return 0;
> }

Pedantic's note: currying an argument actually means creating a function 
that accepts a function of N arguments and returns a function that 
accepts 1 argument and returns a function that accepts N-1 arguments.

But I don't really care if you want to call partial application 
currying.  Just be aware that you're using the term in a way many would 
deem incorrect.
Random link: http://srfi.schemers.org/srfi-26/mail-archive/msg00015.html

--bb