112 lines
3.3 KiB
Scheme
112 lines
3.3 KiB
Scheme
;;
|
|
;; util-proc.scm
|
|
;;
|
|
;; Auxiliary procedure functions.
|
|
;;
|
|
;; ISC License
|
|
;;
|
|
;; Copyright 2023 Brmlab, z.s.
|
|
;; Dominik Pantůček <dominik.pantucek@trustica.cz>
|
|
;;
|
|
;; Permission to use, copy, modify, and/or distribute this software
|
|
;; for any purpose with or without fee is hereby granted, provided
|
|
;; that the above copyright notice and this permission notice appear
|
|
;; in all copies.
|
|
;;
|
|
;; THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
|
|
;; WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
|
|
;; WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
|
|
;; AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
|
|
;; CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
|
|
;; OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
|
|
;; NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
|
|
;; CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
;;
|
|
|
|
(declare (unit util-proc))
|
|
|
|
(import duck)
|
|
|
|
(module*
|
|
util-proc
|
|
#:doc ("This module provides a few simple procedures for querying properties
|
|
of other procedures.")
|
|
(
|
|
improper-list-info
|
|
|
|
procedure-arity=?
|
|
procedure-arity>=?
|
|
procedure-arity>?
|
|
|
|
procedure-num-args
|
|
procedure-arg-names
|
|
)
|
|
|
|
(import scheme
|
|
(chicken base))
|
|
|
|
(define/doc (improper-list-info lst)
|
|
("Returns two values: the proper part of the list length and #t if
|
|
there is an improper list end")
|
|
(let loop ((lst lst)
|
|
(len 0))
|
|
(if (symbol? lst)
|
|
(values len #t)
|
|
(if (null? lst)
|
|
(values len #f)
|
|
(loop (cdr lst)
|
|
(add1 len))))))
|
|
|
|
;; Returns two values: the number of mandatory arguments and
|
|
;; information whether the procedure accepts optional arguments
|
|
(define (procedure-arity-info proc)
|
|
(let-values (((len rest?) (improper-list-info (procedure-information proc))))
|
|
(values (sub1 len) rest?)))
|
|
|
|
(define/doc ((procedure-arity=? n) proc)
|
|
("* ```n``` - integer representing the number of arguments
|
|
* ```proc``` - procedure to query
|
|
|
|
Returns true if the procedure ```proc``` accepts exactly ```n```
|
|
arguments.")
|
|
(let-values (((args rest?) (procedure-arity-info proc)))
|
|
(and (not rest?)
|
|
(= args n))))
|
|
|
|
(define/doc ((procedure-arity>=? n) proc)
|
|
("* ```n``` - integer representing the number of arguments
|
|
* ```proc``` - procedure to query
|
|
|
|
Returns true if the procedure ```proc``` accepts at least ```n```
|
|
arguments.")
|
|
(let-values (((args rest?) (procedure-arity-info proc)))
|
|
(or rest?
|
|
(>= args n))))
|
|
|
|
(define/doc ((procedure-arity>? n) proc)
|
|
("* ```n``` - integer representing the number of arguments
|
|
* ```proc``` - procedure to query
|
|
|
|
Returns true if the procedure ```proc``` accepts more than ```n```
|
|
arguments.")
|
|
(let-values (((args rest?) (procedure-arity-info proc)))
|
|
(or rest?
|
|
(> args n))))
|
|
|
|
(define/doc (procedure-num-args proc)
|
|
("* ```proc``` - procedure to check
|
|
|
|
Returns the number of mandatory arguments.")
|
|
(let-values (((args rest?) (procedure-arity-info proc)))
|
|
args))
|
|
|
|
(define/doc (procedure-arg-names proc)
|
|
("* ```proc``` - procedure to check
|
|
|
|
Returns the (possibly improper) list of arguments the procedure
|
|
```proc``` accepts. If it accepts arbitrary number of arguments, it is
|
|
signalled by simple symbol instead of pair at the last position. If it
|
|
accepts an exact number of arguments, it returns a proper list.")
|
|
(cdr (procedure-information proc)))
|
|
|
|
)
|