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• egg

Ordered sequences as procedures

This is a variant of Mario's callable-datastructures. But contrary to that egg, I don't consider hash-tables, but only ordered sequences, presently lists, pseudolists, vectors and strings. So it makes sense, to consider not only references but slices as well. So, for example, if vec is (make-callable #(0 1 2 3 4 5)), then (vec 1 4) or (vec 4 1) are callables comprising #(1 2 3) or #(4 3 2) respectively.

API

callables

[procedure] (callables)
[procedure] (callables sym)

documentation procedure: returns the list of exported symbols if called without argument, or the documentation of sym otherwise.

make-callable

[procedure] (make-callable seq)

constructor: transforms the sequence into a procedure of zero, one or two arguments.

• zero: returns the original sequence and its length
• one: returns the reference of its integer argument
• two: returns the slice of its integer arguments respecting their order

callable?

[procedure] (callable? xpr)

type predicate

callable-length

[procedure] (callable-length cs)

returns the length of the sequence comprised by the callable cs

Requirements

None

Examples

(import callables)

(define vec (make-callable #(0 1 2 3 4 5)))

(define lst (make-callable '(0 1 2 3 4 5)))

(define pair (make-callable '(0 1 2 3 4 . 5)))

(define str (make-callable "012345"))

(lst 2)
; -> 2

(vec 5)
; -> 5

(str 1)
; -> #\1

(callable-length pair)
; -> 5

(callable-length str)
; -> 6

(callable? lst)
; -> #t

(callable? (pair 2 4))
; -> #t

(vec)
; -> #(0 1 2 3 4 5)

((lst 2 4))
; -> '(2 3)

((pair 4 2))
; -> '(4 3)

((str 2 5))
; -> "234"

((str 5 2))
; -> "543"

Last update

Aug 07, 2020

Author

Juergen Lorenz

License

Copyright (c) 2020, Juergen Lorenz
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Version History

1.0 ; initial version