598 lines
22 KiB
Racket
598 lines
22 KiB
Racket
#lang racket
|
||
|
||
;;; dds/utils
|
||
|
||
;;; Various utilities.
|
||
|
||
(require
|
||
graph
|
||
(for-syntax syntax/parse racket/list))
|
||
|
||
;;; Typed section.
|
||
|
||
(module typed typed/racket
|
||
(require typed/graph typed/rackunit typed-compose typed/racket/stream
|
||
(for-syntax syntax/parse racket/list))
|
||
|
||
(provide
|
||
Variable VariableMapping GeneralPair
|
||
|
||
eval-with eval1-with auto-hash-ref/explicit auto-hash-ref/:
|
||
extract-symbols any->string stringify-variable-mapping string->any
|
||
handle-org-booleans map-sexp read-org-sexp unorg unstringify-pairs
|
||
read-org-variable-mapping unorgv read-symbol-list drop-first-last
|
||
list-sets->list-strings pretty-print-set pretty-print-set-sets
|
||
update-vertices/unweighted update-graph dotit collect-by-key
|
||
collect-by-key/sets ht-values/list->set hash->list/ordered
|
||
multi-split-at lists-transpose in-random)
|
||
|
||
(define-type Variable Symbol)
|
||
(define-type (VariableMapping A) (Immutable-HashTable Variable A))
|
||
|
||
(: eval-with (-> (VariableMapping Any) Any AnyValues))
|
||
(define (eval-with ht expr)
|
||
(parameterize ([current-namespace (make-base-namespace)])
|
||
(for ([(x val) (in-hash ht)]) (namespace-set-variable-value! x val))
|
||
(eval expr)))
|
||
|
||
(: eval1-with (-> (VariableMapping Any) Any Any))
|
||
(define (eval1-with ht expr)
|
||
(call-with-values (λ () (eval-with ht expr))
|
||
(λ args (car args))))
|
||
|
||
(module+ test
|
||
(test-case "eval-with"
|
||
(check-equal? (eval1-with (hash 'a 1 'b 2) '(+ a b 1))
|
||
4)
|
||
(define ht : (VariableMapping Integer) (hash 'a 1 'b 2))
|
||
(define expr : Any '(+ a b 1))
|
||
(check-equal? (eval1-with ht expr)
|
||
4)))
|
||
|
||
(define-syntax (auto-hash-ref/explicit stx)
|
||
(syntax-parse stx
|
||
[(_ (ht:id xs:id ...) body:expr)
|
||
#`(let #,(for/list ([x (syntax->list #'(xs ...))])
|
||
#`[#,x (hash-ref ht '#,x)])
|
||
body)]))
|
||
|
||
(module+ test
|
||
(test-case "auto-hash-ref/explicit"
|
||
(define mytable #hash((a . 3) (b . 4)))
|
||
(check-equal? (auto-hash-ref/explicit (mytable b a)
|
||
(* a b))
|
||
12)
|
||
(define ht #hash((a . #t) (b . #f)))
|
||
(check-equal? (auto-hash-ref/explicit (ht a b)
|
||
(and (not a) b))
|
||
#f)))
|
||
|
||
(define-syntax (auto-hash-ref/: stx)
|
||
(syntax-parse stx
|
||
[(_ ht:id body)
|
||
(let* ([names/: (collect-colons (syntax->datum #'body))])
|
||
#`(let #,(for/list ([x names/:])
|
||
;; put x in the same context as body
|
||
#`[#,(datum->syntax #'body x)
|
||
(hash-ref ht '#,(strip-colon x))])
|
||
body))]))
|
||
|
||
(module+ test
|
||
(test-case "auto-hash-ref/:"
|
||
(define ht1 #hash((x . #t) (y . #t) (t . #f)))
|
||
(define z #t)
|
||
(check-equal? (auto-hash-ref/: ht1
|
||
(and :x (not :y) z (or (and :t) :x)))
|
||
#f)
|
||
(define ht2 #hash((a . 1) (b . 2)))
|
||
(check-equal? (auto-hash-ref/: ht2 (+ :a (* 2 :b)))
|
||
5)))
|
||
|
||
;;; The helper functions for auto-hash-ref/:.
|
||
(begin-for-syntax
|
||
;; Collect all the symbols starting with a colon in datum.
|
||
(define (collect-colons datum)
|
||
(remove-duplicates
|
||
(flatten
|
||
(for/list ([token datum])
|
||
(cond
|
||
[(symbol? token)
|
||
(let ([name (symbol->string token)])
|
||
(if (eq? #\: (string-ref name 0))
|
||
token
|
||
'()))]
|
||
[(list? token)
|
||
(collect-colons token)]
|
||
[else '()])))))
|
||
|
||
;; Strip the leading colon off x.
|
||
(define (strip-colon x)
|
||
(let ([x-str (symbol->string x)])
|
||
(if (eq? #\: (string-ref x-str 0))
|
||
(string->symbol (substring x-str 1))
|
||
x))))
|
||
|
||
(: extract-symbols (-> Any (Listof Symbol)))
|
||
(define (extract-symbols form)
|
||
(: extract-rec (-> Any (Listof Any)))
|
||
(define (extract-rec form)
|
||
(match form
|
||
[(? symbol?) (list form)]
|
||
[(? list?)
|
||
(flatten (for/list : (Listof Any)
|
||
([x form])
|
||
(extract-symbols x)))]
|
||
[else '()]))
|
||
(cast (extract-rec form) (Listof Symbol)))
|
||
|
||
(module+ test
|
||
(test-case "extract-symbols"
|
||
(check-equal? (extract-symbols '(1 (2 3) x (y z 3)))
|
||
'(x y z))))
|
||
|
||
(: any->string (-> Any String))
|
||
(define (any->string x)
|
||
(with-output-to-string (λ () (display x))))
|
||
|
||
(module+ test
|
||
(test-case "any->string"
|
||
(check-equal? (any->string 'a) "a")
|
||
(check-equal? (any->string '(a 1 (x y))) "(a 1 (x y))")
|
||
(check-equal? (any->string "hello") "hello")))
|
||
|
||
(: stringify-variable-mapping (-> (VariableMapping Any) (VariableMapping String)))
|
||
(define (stringify-variable-mapping ht)
|
||
(for/hash : (VariableMapping String)
|
||
([(key val) (in-hash ht)]) (values key (any->string val))))
|
||
|
||
(module+ test
|
||
(test-case "stringify-variable-mapping"
|
||
(define mp (stringify-variable-mapping #hash((a . (and a b)) (b . (not b)))))
|
||
(check-equal? (hash-ref mp 'a) "(and a b)")
|
||
(check-equal? (hash-ref mp 'b) "(not b)")))
|
||
|
||
(: string->any (-> String Any))
|
||
(define (string->any str)
|
||
(with-input-from-string str (λ () (read))))
|
||
|
||
(module+ test
|
||
(test-case "string->any"
|
||
(check-equal? (string->any "(or b (not a))") '(or b (not a)))
|
||
(check-equal? (string->any "14") 14)))
|
||
|
||
;;; Given a sexp, converts all "#f" to #f and "#t" to #t.
|
||
;;;
|
||
;;; When I read Org-mode tables, I pump them through a call to the
|
||
;;; prin1 because the Elisp sexps seems incompatible with Racket.
|
||
;;; On the other hand, Racket Booleans seem to upset Elisp a little,
|
||
;;; so prin1 wraps them in additional double quotes. This function
|
||
;;; removes those quotes.
|
||
(: handle-org-booleans (-> Any Any))
|
||
(define/match (handle-org-booleans datum)
|
||
[("#t") #t]
|
||
[("#f") #f]
|
||
[((? list?)) (map handle-org-booleans datum)]
|
||
[ (_) datum])
|
||
|
||
(module+ test
|
||
(test-case "handle-org-booleans"
|
||
(check-equal? (handle-org-booleans "#t") #t)
|
||
(check-equal? (handle-org-booleans "#f") #f)
|
||
(check-equal? (handle-org-booleans '("#t" "#f")) '(#t #f))
|
||
(check-equal? (handle-org-booleans "t") "t")))
|
||
|
||
(: map-sexp (-> (-> Any Any) Any Any))
|
||
(define (map-sexp func sexp)
|
||
(match sexp
|
||
[(? list?) (map ((curry map-sexp) func) sexp)]
|
||
[datum (func datum)]))
|
||
|
||
(module+ test
|
||
(test-case "map-sexp"
|
||
(check-equal? (map-sexp (λ (x) (add1 (cast x Number))) '(1 2 (4 10) 3))
|
||
'(2 3 (5 11) 4))))
|
||
|
||
(: read-org-sexp (-> String Any))
|
||
(define read-org-sexp
|
||
(compose ((curry map-sexp) (match-lambda
|
||
[(and (? string?) str) (string->any str)]
|
||
[x x]))
|
||
string->any))
|
||
(define unorg read-org-sexp)
|
||
|
||
(module+ test
|
||
(test-case "read-org-sexp"
|
||
(check-equal? (read-org-sexp "((\"a\" \"(and a b)\") (\"b\" \"(or b (not a))\"))")
|
||
'((a (and a b)) (b (or b (not a)))))
|
||
(check-equal? (unorg "(#t \"#t\" \"#t \" '(1 2 \"#f\"))")
|
||
'(#t #t #t '(1 2 #f)))))
|
||
|
||
(define-type (GeneralPair A B) (U (Pair A B) (List A B)))
|
||
|
||
(: unstringify-pairs (-> (Listof (GeneralPair String Any))
|
||
(Listof (GeneralPair Symbol Any))))
|
||
(define (unstringify-pairs pairs)
|
||
(for/list ([p pairs])
|
||
(match p
|
||
[(list key val)
|
||
(cons (string->symbol key) (if (string? val)
|
||
(string->any val)
|
||
val))]
|
||
[(cons key val)
|
||
(cons (string->symbol key) (if (string? val)
|
||
(string->any val)
|
||
val))])))
|
||
|
||
(module+ test
|
||
(test-case "unstringify-pairs"
|
||
(check-equal? (unstringify-pairs '(("a" . "1") ("b" . "(and a (not b))")))
|
||
'((a . 1) (b . (and a (not b)))))
|
||
(check-equal? (unstringify-pairs '(("a" . 1) ("b" . "(and a (not b))")))
|
||
'((a . 1) (b . (and a (not b)))))))
|
||
|
||
(: read-org-variable-mapping (-> String (VariableMapping Any)))
|
||
(define read-org-variable-mapping
|
||
(multi-compose
|
||
(λ ([pairs : (Listof (Pair Symbol Any))])
|
||
(make-immutable-hash pairs))
|
||
(λ (sexp)
|
||
(unstringify-pairs (cast sexp (Listof (GeneralPair String Any)))))
|
||
string->any))
|
||
|
||
;;; A synonym for read-org-variable-mapping.
|
||
(define unorgv read-org-variable-mapping)
|
||
|
||
(module+ test
|
||
(test-case "read-org-variable-mapping"
|
||
(define m1 (read-org-variable-mapping "((\"a\" \"(and a b)\") (\"b\" \"(or b (not a))\"))"))
|
||
(define m2 (read-org-variable-mapping "((\"a\" . \"(and a b)\") (\"b\" . \"(or b (not a))\"))"))
|
||
(define m3 (unorgv "((\"a\" . \"(and a b)\") (\"b\" . \"(or b (not a))\"))"))
|
||
(check-equal? (hash-ref m1 'a) '(and a b))
|
||
(check-equal? (hash-ref m2 'a) '(and a b))
|
||
(check-equal? (hash-ref m3 'a) '(and a b))
|
||
(check-equal? (hash-ref m1 'b) '(or b (not a)))
|
||
(check-equal? (hash-ref m2 'b) '(or b (not a)))
|
||
(check-equal? (hash-ref m3 'b) '(or b (not a)))))
|
||
|
||
(: read-symbol-list (-> String (Listof Symbol)))
|
||
(define (read-symbol-list str)
|
||
(cast (string->any (string-append "(" str ")")) (Listof Symbol)))
|
||
|
||
(module+ test
|
||
(test-case "read-symbol-list"
|
||
(check-equal? (read-symbol-list "a b c") '(a b c))))
|
||
|
||
(: drop-first-last (-> String String))
|
||
(define (drop-first-last str)
|
||
(substring str 1 (- (string-length str) 1)))
|
||
|
||
(module+ test
|
||
(test-case "drop-first-last"
|
||
(check-equal? (drop-first-last "(a b)") "a b")))
|
||
|
||
(: list-sets->list-strings (-> (Listof (Setof Any)) (Listof String)))
|
||
(define (list-sets->list-strings lst)
|
||
(map (multi-compose drop-first-last
|
||
any->string
|
||
(λ ([x : (Setof Any)])
|
||
(set->list x))) lst))
|
||
|
||
(module+ test
|
||
(test-case "list-sets->list-strings"
|
||
(check-equal? (list-sets->list-strings (list (set 'x 'y) (set 'z) (set) (set 't)))
|
||
'("x y" "z" "" "t"))))
|
||
|
||
(: pretty-print-set (-> (Setof Any) String))
|
||
(define (pretty-print-set s)
|
||
(string-join (sort (set-map s any->string) string<?)))
|
||
|
||
(module+ test
|
||
(test-case "pretty-print-set"
|
||
(check-equal? (pretty-print-set (set 'a 'b 1)) "1 a b")))
|
||
|
||
(: pretty-print-set-sets (-> (Setof (Setof Any)) String))
|
||
(define (pretty-print-set-sets ms)
|
||
(string-join (for/list ([m ms]) : (Listof String)
|
||
(format "{~a}" (pretty-print-set m))) ""))
|
||
|
||
(module+ test
|
||
(test-case "pretty-print-set-sets"
|
||
(check-equal? (pretty-print-set-sets (set (set 'a 'b) (set 'c))) "{a b}{c}")))
|
||
|
||
(define dotit (compose display graphviz))
|
||
|
||
(: update-vertices/unweighted (-> Graph (-> Any Any) Graph))
|
||
(define (update-vertices/unweighted gr func)
|
||
(unweighted-graph/directed
|
||
(for/list ([e (in-edges gr)])
|
||
(match-let ([(list u v) e])
|
||
(list (func u) (func v))))))
|
||
|
||
(module+ test
|
||
(test-case "update-vertices/unweighted"
|
||
(define gr1 (directed-graph '((a b) (b c))))
|
||
(define gr2 (undirected-graph '((a b) (b c))))
|
||
(define (dbl [x : Any])
|
||
(define x-str (symbol->string (cast x Symbol)))
|
||
(string->symbol (string-append x-str x-str)))
|
||
(define new-gr1 (update-vertices/unweighted gr1 dbl))
|
||
(define new-gr2 (update-vertices/unweighted gr2 dbl))
|
||
|
||
(check-false (has-vertex? new-gr1 'a))
|
||
(check-true (has-vertex? new-gr1 'aa))
|
||
(check-false (has-vertex? new-gr1 'b))
|
||
(check-true (has-vertex? new-gr1 'bb))
|
||
(check-false (has-vertex? new-gr1 'c))
|
||
(check-true (has-vertex? new-gr1 'cc))
|
||
(check-true (has-edge? new-gr1 'aa 'bb))
|
||
(check-true (has-edge? new-gr1 'bb 'cc))
|
||
|
||
(check-true (has-edge? new-gr2 'aa 'bb))
|
||
(check-true (has-edge? new-gr2 'bb 'aa))
|
||
(check-true (has-edge? new-gr2 'bb 'cc))
|
||
(check-true (has-edge? new-gr2 'cc 'bb))))
|
||
|
||
(: update-graph (->* (Graph) (#:v-func (-> Any Any) #:e-func (-> Any Any)) Graph))
|
||
(define (update-graph gr #:v-func [v-func identity] #:e-func [e-func identity])
|
||
(cond
|
||
[(unweighted-graph? gr)
|
||
(unweighted-graph/directed
|
||
(for/list ([e (in-edges gr)]) : (Listof (List Any Any))
|
||
(match-let ([(list u v) e])
|
||
(list (v-func u) (v-func v)))))]
|
||
[else
|
||
(weighted-graph/directed
|
||
(for/list ([e (in-edges gr)]) : (Listof (List Any Any Any))
|
||
(match-let ([(list u v) e])
|
||
(list (e-func (edge-weight gr u v))
|
||
(v-func u) (v-func v)))))]))
|
||
|
||
(module+ test
|
||
(test-case "update-graph"
|
||
(define gr1 (directed-graph '((a b) (b c))))
|
||
(define gr2 (undirected-graph '((a b) (b c))))
|
||
(define (dbl [x : Any])
|
||
(define x-str (symbol->string (cast x Symbol)))
|
||
(string->symbol (string-append x-str x-str)))
|
||
(define new-gr1-ug (update-graph gr1 #:v-func dbl))
|
||
(define new-gr2-ug (update-graph gr2 #:v-func dbl))
|
||
(define gr3 (weighted-graph/directed '((10 a b) (11 b c))))
|
||
(define new-gr3 (update-graph gr3
|
||
#:v-func dbl
|
||
#:e-func (λ (x) (* 2 (cast x Number)))))
|
||
|
||
(check-false (has-vertex? new-gr1-ug 'a))
|
||
(check-true (has-vertex? new-gr1-ug 'aa))
|
||
(check-false (has-vertex? new-gr1-ug 'b))
|
||
(check-true (has-vertex? new-gr1-ug 'bb))
|
||
(check-false (has-vertex? new-gr1-ug 'c))
|
||
(check-true (has-vertex? new-gr1-ug 'cc))
|
||
(check-true (has-edge? new-gr1-ug 'aa 'bb))
|
||
(check-true (has-edge? new-gr1-ug 'bb 'cc))
|
||
|
||
(check-true (has-edge? new-gr2-ug 'aa 'bb))
|
||
(check-true (has-edge? new-gr2-ug 'bb 'aa))
|
||
(check-true (has-edge? new-gr2-ug 'bb 'cc))
|
||
(check-true (has-edge? new-gr2-ug 'cc 'bb))
|
||
|
||
(check-true (has-edge? new-gr3 'aa 'bb))
|
||
(check-false (has-edge? new-gr3 'bb 'aa))
|
||
(check-true (has-edge? new-gr3 'bb 'cc))
|
||
(check-false (has-edge? new-gr3 'cc 'bb))
|
||
(check-equal? (edge-weight new-gr3 'aa 'bb) 20)
|
||
(check-equal? (edge-weight new-gr3 'bb 'cc) 22)))
|
||
|
||
(: collect-by-key (All (a b) (-> (Listof a) (Listof b)
|
||
(Values (Listof a) (Listof (Listof b))))))
|
||
(define (collect-by-key keys vals)
|
||
(for/fold ([ht : (HashTable a (Listof b))
|
||
(make-immutable-hash)]
|
||
#:result (values (hash-keys ht) (hash-values ht)))
|
||
([e keys]
|
||
[l vals])
|
||
((inst hash-update a (Listof b)) ht e (λ (ls) (cons l ls)) (λ () empty))))
|
||
|
||
(module+ test
|
||
(test-case "collect-by-key"
|
||
(define-values (e1 l1) (collect-by-key '((1 2) (1 3)) '(a b)))
|
||
(define-values (e2 l2) (collect-by-key '((1 2) (1 2)) '(a b)))
|
||
(check-equal? e1 '((1 2) (1 3))) (check-equal? l1 '((a) (b)))
|
||
(check-equal? e2 '((1 2))) (check-equal? l2 '((b a)))))
|
||
|
||
(: collect-by-key/sets (All (a b) (-> (Listof a) (Listof b)
|
||
(Values (Listof a) (Listof (Setof b))))))
|
||
(define (collect-by-key/sets edges labels)
|
||
(define-values (es ls) (collect-by-key edges labels))
|
||
(values es ((inst map (Setof b) (Listof b)) list->set ls)))
|
||
|
||
(module+ test
|
||
(test-case "collect-by-key/sets"
|
||
(define-values (e3 l3) (collect-by-key/sets '(a b a) '(1 2 1)))
|
||
(check-equal? e3 '(b a)) (check-equal? l3 (list (set 2) (set 1)))))
|
||
|
||
;;; Converts the values of a hash table from lists to sets.
|
||
(: ht-values/list->set (All (a b) (-> (HashTable a (Listof b)) (HashTable a (Setof b)))))
|
||
(define (ht-values/list->set ht)
|
||
(for/hash ([(k v) (in-hash ht)]) : (HashTable a (Setof b))
|
||
(values k (list->set v))))
|
||
|
||
(module+ test
|
||
(test-case "ht-values/list->set"
|
||
(check-equal? (ht-values/list->set #hash((a . (1 1))))
|
||
(hash 'a (set 1)))))
|
||
|
||
;; TODO: Remove after Racket 8.4.
|
||
(: hash->list/ordered (All (a b) (-> (HashTable a b) (Listof (Pairof a b)))))
|
||
(define (hash->list/ordered ht)
|
||
((inst hash-map a b (Pairof a b)) ht cons #t))
|
||
|
||
(module+ test
|
||
(test-case "hash->list/ordered"
|
||
(check-equal? (hash->list/ordered #hash((b . 1) (a . 1)))
|
||
'((a . 1) (b . 1)))))
|
||
|
||
(: multi-split-at (All (a) (-> (Listof (Listof a)) Integer
|
||
(Values (Listof (Listof a)) (Listof (Listof a))))))
|
||
(define (multi-split-at lists pos)
|
||
(for/fold ([lefts : (Listof (Listof a)) '()]
|
||
[rights : (Listof (Listof a)) '()]
|
||
#:result (values (reverse lefts) (reverse rights)))
|
||
([lst (in-list lists)])
|
||
(define-values (left right) ((inst split-at a) lst pos))
|
||
(values (cons left lefts) (cons right rights))))
|
||
|
||
(module+ test
|
||
(test-case "multi-split-at"
|
||
(define-values (l1 l2) (multi-split-at '((1 2 3) (a b c)) 2))
|
||
(check-equal? l1 '((1 2) (a b))) (check-equal? l2 '((3) (c)))))
|
||
|
||
;; https://racket.discourse.group/t/get-to-type-apply-in-parallel-lst/683
|
||
(: lists-transpose (All (a ...) (-> (List (Listof a) ... a) (Listof (List a ... a)))))
|
||
(define (lists-transpose lists)
|
||
(sequence->list (in-values-sequence (apply in-parallel lists))))
|
||
|
||
(module+ test
|
||
(test-case "lists-transpose"
|
||
(check-equal? (lists-transpose '((1 2) (a b))) '((1 a) (2 b)))))
|
||
|
||
(: in-random (case->
|
||
(-> (Sequenceof Flonum))
|
||
(-> Integer (Sequenceof Nonnegative-Fixnum))
|
||
(-> Integer Integer (Sequenceof Nonnegative-Fixnum))))
|
||
(define in-random
|
||
(case-lambda
|
||
[() (stream-cons (random) (in-random))]
|
||
[(k) (stream-cons (random k) (in-random k))]
|
||
[(min max) (stream-cons (random min max) (in-random min max))]))
|
||
|
||
(module+ test
|
||
(test-case "in-random"
|
||
(random-seed 1)
|
||
(check-equal? (stream->list (stream-take (in-random 100) 10))
|
||
'(50 84 10 99 94 88 43 41 63 50))
|
||
(check-equal? (stream->list (stream-take (in-random 50 100) 10))
|
||
'(57 98 82 83 61 53 73 82 50 80))
|
||
(check-equal? (stream->list (stream-take (in-random) 10))
|
||
'(0.2718099186980313
|
||
0.7319496826374751
|
||
0.17365244033739616
|
||
0.5593031443038616
|
||
0.3345256691289459
|
||
0.9845704615094365
|
||
0.05753824253751768
|
||
0.22552976312818723
|
||
0.21646500425988832
|
||
0.15188352823997242))))
|
||
)
|
||
|
||
(require 'typed)
|
||
(provide eval-with eval1-with auto-hash-ref/explicit auto-hash-ref/:
|
||
extract-symbols any->string stringify-variable-mapping string->any
|
||
map-sexp read-org-sexp unorg unstringify-pairs
|
||
read-org-variable-mapping unorgv read-symbol-list drop-first-last
|
||
list-sets->list-strings pretty-print-set pretty-print-set-sets
|
||
update-vertices/unweighted update-graph dotit collect-by-key
|
||
collect-by-key/sets ht-values/list->set hash->list/ordered
|
||
multi-split-at lists-transpose in-random)
|
||
|
||
;;; Untyped section.
|
||
|
||
(provide
|
||
;; Functions
|
||
(contract-out [cartesian-product/stream (->* () #:rest (listof stream?) stream?)]
|
||
[boolean-power (-> number? (listof (listof boolean?)))]
|
||
[boolean-power/stream (-> number? (stream/c (listof boolean?)))]
|
||
[any->01 (-> any/c (or/c 0 1))]
|
||
[01->boolean (-> (or/c 0 1) boolean?)])
|
||
;; Contracts
|
||
(contract-out [variable-mapping? contract?]
|
||
[string-variable-mapping? contract?]
|
||
[general-pair/c (-> contract? contract? contract?)]))
|
||
|
||
(module+ test
|
||
(require rackunit))
|
||
|
||
|
||
(define (variable-mapping? dict) (hash/c symbol? any/c))
|
||
|
||
;;; A string variable mapping is a mapping from variables to strings.
|
||
(define (string-variable-mapping? dict) (hash/c symbol? string?))
|
||
|
||
;;; A contract allowing pairs constructed via cons or via list.
|
||
(define (general-pair/c key-contract val-contract)
|
||
(or/c (list/c key-contract val-contract)
|
||
(cons/c key-contract val-contract)))
|
||
|
||
|
||
;;; ===========================
|
||
;;; Additional stream utilities
|
||
;;; ===========================
|
||
|
||
|
||
;;; Returns the Cartesian product of the given streams. The result is
|
||
;;; a stream whose elements are the elements of the Cartesian product.
|
||
;;;
|
||
;;; The implementation is inspired from the implementation of
|
||
;;; cartesian-product in racket/list.
|
||
(define (cartesian-product/stream . ss)
|
||
;; Cartesian product of two streams, produces an improper pair.
|
||
(define (cp-2 ss1 ss2)
|
||
(for*/stream ([s1 (in-stream ss1)] [s2 (in-stream ss2)]) (cons s1 s2)))
|
||
;; Fold-right over the list of streams. The value for the fold is a
|
||
;; 1-value stream containing the empty list, which makes all the
|
||
;; lists proper.
|
||
(foldr cp-2 (sequence->stream (in-value (list))) ss))
|
||
|
||
(module+ test
|
||
(test-case "cartesian-product/stream"
|
||
(check-equal? (stream->list (cartesian-product/stream (in-range 3) (in-range 4 6) '(a b)))
|
||
'((0 4 a)
|
||
(0 4 b)
|
||
(0 5 a)
|
||
(0 5 b)
|
||
(1 4 a)
|
||
(1 4 b)
|
||
(1 5 a)
|
||
(1 5 b)
|
||
(2 4 a)
|
||
(2 4 b)
|
||
(2 5 a)
|
||
(2 5 b)))))
|
||
|
||
|
||
;;; ==================
|
||
;;; Boolean operations
|
||
;;; ==================
|
||
|
||
;;; Returns the n-th Cartesian power of the Boolean domain: {0,1}^n.
|
||
(define (boolean-power n) (apply cartesian-product (make-list n '(#f #t))))
|
||
|
||
(module+ test
|
||
(test-case "boolean-power"
|
||
(check-equal? (boolean-power 2) '((#f #f) (#f #t) (#t #f) (#t #t)))))
|
||
|
||
;;; Like boolean-power, but returns a stream whose elements the
|
||
;;; elements of the Cartesian power.
|
||
(define (boolean-power/stream n) (apply cartesian-product/stream (make-list n '(#f #t))))
|
||
|
||
(module+ test
|
||
(test-case "boolean-power/stream"
|
||
(check-equal? (stream->list (boolean-power/stream 2)) '((#f #f) (#f #t) (#t #f) (#t #t)))))
|
||
|
||
;;; Converts any non-#f value to 1 and #f to 0.
|
||
(define (any->01 x) (if x 1 0))
|
||
|
||
(module+ test
|
||
(test-case "any->01"
|
||
(check-equal? (any->01 #t) 1)
|
||
(check-equal? (any->01 #f) 0)))
|
||
|
||
;;; Converts 0 to #f and 1 to #t
|
||
(define (01->boolean x)
|
||
(case x [(0) #f] [else #t]))
|
||
|
||
(module+ test
|
||
(test-case "01->boolean"
|
||
(check-equal? (01->boolean 0) #f)
|
||
(check-equal? (01->boolean 1) #t)))
|