Passing keywords from a list

[Dimaugh Silvestris]

Is it possible to reproduce this behavior

((lambda (#:color color #:size size) (display (cons color size))) #:color "red" #:size 3)

when what I have is a list such as '(#:color "red" #:size 3) ?
How can I feed keyword arguments stored in a list as symbols in a way that doesn't involve parsing manually?

[Sorawee Porncharoenwase]

If you are OK with preprocessing the argument list into a dictionary, then you can use keyword-apply/dict.

For example:

#lang racket

(require racket/dict)

(define proc (lambda (#:color color #:size size) (display (cons color size))))
(define args '(#:color "red" #:size 3))
(define args*
  (for/hash ([chunk (in-slice 2 args)])
    (values (first chunk) (second chunk))))

(keyword-apply/dict proc args* '())

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[Dimaugh Silvestris]

Thanks! Your answer led me to find keyword-apply, so I just wrote (I use def as abbreviation for define):

(def (parse-args xs)
  (def (fn ks kvs vs xs)
    (cond [(empty? xs)  (map reverse (list ks kvs vs))]
          [(keyword? (car xs))
           (fn (cons (car xs) ks) (cons (cadr xs) kvs) vs (drop xs 2))]
          [else (fn ks kvs (cons (car xs) vs) (cdr xs))]))
  (fn '[] '[] '[] xs))

(def (func-args func args)
  (apply keyword-apply func (parse-args args)))

And now I can do

:

(def (suma a b #:c [c 0]) (+ a b c))

(func-args suma (list 1 2 #:c 3))

and it works fine.

Thanks again!

[Dimaugh Silvestris]

Just in case somebody has a similar issue and finds this:
In the end I used keyword-apply/sort , which doesn't requiere keywords to follow the same order they do in the function definition.