giles
d992788a03
Some checks failed
Test, Build, and Deploy / test-build-deploy (push) Failing after 27s
Two-line definitions over project + host even?/odd?. Ground-only — no
relational behaviour, but they pair cleanly with membero for filtered
enumeration:
(fresh (x) (membero x (list 1 2 3 4 5 6)) (even-i x) (== q x))
-> (2 4 6)
5 new tests, 416/416 cumulative.
71 lines
1.5 KiB
Plaintext
71 lines
1.5 KiB
Plaintext
;; lib/minikanren/intarith.sx — fast integer arithmetic via project.
|
|
;;
|
|
;; These are ground-only escapes into host arithmetic. They run at native
|
|
;; speed (host ints) but require their arguments to walk to actual numbers
|
|
;; — they are not relational the way `pluso` (Peano) is. Use them when
|
|
;; the puzzle size makes Peano impractical.
|
|
;;
|
|
;; Naming: `-i` suffix marks "integer-only" goals.
|
|
|
|
(define
|
|
pluso-i
|
|
(fn
|
|
(a b c)
|
|
(project
|
|
(a b)
|
|
(if (and (number? a) (number? b)) (== c (+ a b)) fail))))
|
|
|
|
(define
|
|
minuso-i
|
|
(fn
|
|
(a b c)
|
|
(project
|
|
(a b)
|
|
(if (and (number? a) (number? b)) (== c (- a b)) fail))))
|
|
|
|
(define
|
|
*o-i
|
|
(fn
|
|
(a b c)
|
|
(project
|
|
(a b)
|
|
(if (and (number? a) (number? b)) (== c (* a b)) fail))))
|
|
|
|
(define
|
|
lto-i
|
|
(fn
|
|
(a b)
|
|
(project
|
|
(a b)
|
|
(if (and (number? a) (and (number? b) (< a b))) succeed fail))))
|
|
|
|
(define
|
|
lteo-i
|
|
(fn
|
|
(a b)
|
|
(project
|
|
(a b)
|
|
(if (and (number? a) (and (number? b) (<= a b))) succeed fail))))
|
|
|
|
(define
|
|
neqo-i
|
|
(fn
|
|
(a b)
|
|
(project
|
|
(a b)
|
|
(if (and (number? a) (and (number? b) (not (= a b)))) succeed fail))))
|
|
|
|
(define numbero (fn (x) (project (x) (if (number? x) succeed fail))))
|
|
|
|
(define stringo (fn (x) (project (x) (if (string? x) succeed fail))))
|
|
|
|
(define symbolo (fn (x) (project (x) (if (symbol? x) succeed fail))))
|
|
|
|
(define
|
|
even-i
|
|
(fn (n) (project (n) (if (and (number? n) (even? n)) succeed fail))))
|
|
|
|
(define
|
|
odd-i
|
|
(fn (n) (project (n) (if (and (number? n) (odd? n)) succeed fail))))
|