On Wed, Feb 08, 2017 at 01:57:22PM +0100, pd wrote:
> *I feel* curry to be a unfortunate name for that function because I expect
> curry to be a function that once applied to another function with n
> parameters it returns a chain of applying functions with exactly one
> argument, that is having:
>
> : (de sum (x y) (+ x y))
>
> I expect a function named curry to behave this way:
>
> (curry 'sum) -> ((x) '((y) (+ x y))) # it is really pseudocode not
> actually picolisp code since returning a lambda quoted this way won't do
> the job
>
> or in classical lisp notation:
>
> (curry 'sum) -> (lambda (x) (lambda (y) (+ x y)))
>
> in a way you now can apply the curryfied sum partially: ((curry 'sum) 2)
> -> ((y) (+ 2 y)) or totally: ((curry 'sum) 3 4) -> 7
>
> But picolisp curry function doesn't do that, it simply returns a lambda
You can easily use PicoLisp's 'curry' to built the classical curry
(de classiCurry (Fun)
(let Par (list (caar Fun))
(list Par
(cons 'curry Par (cdar Fun) (cdr Fun)) ) ) )
For your example (I use 'add' instead of 'sum' because the latter is built-in):
: (de add (X Y) (+ X Y))
-> add
: (classiCurry add)
-> ((X) (curry (X) (Y) (+ X Y)))
: ((classiCurry add) 2)
-> ((Y) (job '((X . 2)) (+ X Y))
If you know that your function does not modify the values of its parameters, you
can use pattern variables to get more efficient code with constants and no need
for a 'job' closure:
: (de add (@X Y) (+ @X Y))
-> add
: (classiCurry add)
-> ((@X) (curry (@X) (Y) (+ @X Y)))
: ((classiCurry add) 2)
-> ((Y) (+ 2 Y))
In both cases you get:
: (((classiCurry add) 2) 3)
-> 5
♪♫ Alex
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