8.12
4 Higher Order Functions with Keywords
4.1 Map with keyword arguments
| (require kw-utils/kw-map) | package: kw-utils |
procedure
(map proc lst ... #:<kw> lst2 ...) → list?
proc : procedure? lst : list? lst2 : list?
like map from racket/base, but accepts keyword arguments as
well as positional arguments.
Examples:
> (require kw-utils/kw-map racket/math) > (map (λ (x) (+ x 1)) '(1 2 3 4)) '(2 3 4 5)
> (map (λ (#:x x) (+ x 1)) #:x '(1 2 3 4)) '(2 3 4 5)
> (map (λ (x y) (+ x y)) '(1 2 3 4) '(10 100 1000 10000)) '(11 102 1003 10004)
> (map (λ (x #:y y) (+ x y)) '(1 2 3 4) #:y '(10 100 1000 10000)) '(11 102 1003 10004)
> (define (KE #:m m #:v v) (* 1/2 m (sqr v))) > (map KE #:m '(2 2 2 2) #:v '(0 1 2 3)) '(0 1 4 9)
> (map KE #:m '(0 1 2 3) #:v '(0 1 2 3)) '(0 1/2 4 27/2)
> (map KE #:m '(1 2 1/2 2/9) #:v '(0 1 2 3)) '(0 1 1 1)
4.2 Partial application with keywords
| (require kw-utils/partial) | package: kw-utils |
procedure
(partial f arg ... #:<kw> kw-arg ...) → procedure?
f : procedure? arg : any/c kw-arg : any/c (partial #:<kw> kw-arg ...) → procedure? kw-arg : any/c
Similar to curry, but better thought of as a generalization of
partial from rackjure. Unlike curry,
(but like the rackjure version), it does not care about function
arity, and so has much simpler behavior, so that
((partial f in-arg ...) out-arg ...) is equivalent to
(f in-arg ... out-arg ...) no matter what arity f has.
It also generalizes this idea to include keyword arguments.
Examples:
procedure
f : procedure? arg : any/c kw-arg : any/c
A procedure for normal function application.
(partial #:<kw> kw-arg ... ...) is equivalent to
(partial app #:<kw> kw-arg ... ...).
Examples:
4.3 Creating functions that map over lists
| (require kw-utils/mapper) | package: kw-utils |
procedure
(mapper f arg ... #:<kw> kw-arg ...) → procedure?
f : procedure? arg : any/c kw-arg : any/c (mapper #:<kw> kw-arg ...) → procedure? kw-arg : any/c
The one-argument case is equivalent to a curried version of map.