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mal/racket/types.rkt
2016-02-15 14:27:47 -05:00

124 lines
3.3 KiB
Racket

#lang racket
(provide blank-exn? make-blank-exn mal-exn? make-mal-exn mal-exn-val
malfunc malfunc? malfunc-fn
malfunc-ast malfunc-env malfunc-params malfunc-macro? malfunc-meta
_partition _equal? _printf
nil _nil? _keyword _keyword? _string?
_to_list _sequential? _count _empty? _nth _first _rest _map
_assoc _dissoc _get
atom atom? atom-val set-atom-val!)
(define-struct (blank-exn exn:fail:user) ())
(define-struct (mal-exn exn:fail:user) [val])
(define nil%
(class object%
(super-new)))
(define nil (new nil%))
(define (_nil? obj)
(eq? nil obj))
(struct malfunc [fn ast env params macro? meta]
#:property prop:procedure (struct-field-index fn))
;; General functions
;; From: http://stackoverflow.com/questions/8725832/how-to-split-list-into-evenly-sized-chunks-in-racket-scheme/8731622#8731622
(define (_partition n xs)
(if (null? xs)
'()
(let ((first-chunk (take xs n))
(rest (drop xs n)))
(cons first-chunk (_partition n rest)))))
(define (_equal_seqs? seq_a seq_b)
(let ([a (_to_list seq_a)]
[b (_to_list seq_b)])
(and (= (length a) (length b))
(andmap (lambda (va vb) (_equal? va vb)) a b))))
(define (_equal_hashes? a b)
(if (= (hash-count a) (hash-count b))
(let ([keys (hash-keys a)])
(andmap (lambda (k) (_equal? (_get a k) (_get b k))) keys))
#f))
(define (_equal? a b)
(cond
[(and (_sequential? a) (_sequential? b)) (_equal_seqs? a b)]
[(and (hash? a) (hash? b)) (_equal_hashes? a b)]
[else (equal? a b)]))
;; printf with flush
(define _printf (lambda a (apply printf a) (flush-output)))
;; Keywords
(define (_keyword str)
(string-append "\u029e" str))
(define (_keyword? k)
(and (string? k) (regexp-match? #px"^\u029e" k)))
;; Strings
(define (_string? s)
(and (string? s) (not (_keyword? s))))
;; Lists and vectors
(define (_to_list a)
(if (vector? a) (vector->list a) a))
(define (_sequential? seq)
(or (vector? seq) (list? seq)))
(define (_count seq)
(cond [(_nil? seq) 0]
[(vector? seq) (vector-length seq)]
[else (length seq)]))
(define (_empty? seq)
(eq? 0 (_count seq)))
(define (_nth seq idx)
(cond [(>= idx (_count seq)) (raise "nth: index out of range")]
[(vector? seq) (vector-ref seq idx)]
[else (list-ref seq idx)]))
(define (_first seq)
(cond [(vector? seq) (if (_empty? seq) nil (vector-ref seq 0))]
[else (if (_empty? seq) nil (list-ref seq 0))]))
(define (_rest seq)
(cond [(vector? seq) (if (_empty? seq) '() (rest (vector->list seq)))]
[else (if (_empty? seq) '() (rest seq))]))
(define (_map f seq)
(cond [(vector? seq) (vector-map f seq)]
[else (map f seq)]))
;; Hash maps
(define _assoc
(lambda args
(let ([new-hm (hash-copy (first args))]
[pairs (_partition 2 (rest args))])
(map (lambda (k_v)
(hash-set! new-hm (first k_v) (second k_v))) pairs)
new-hm)))
(define _dissoc
(lambda args
(let ([new-hm (hash-copy (first args))])
(map (lambda (k) (hash-remove! new-hm k)) (rest args))
new-hm)))
(define (_get hm k)
(cond [(_nil? hm) nil]
[(dict-has-key? hm k) (hash-ref hm k)]
[else nil]))
;; Atoms
(struct atom [val] #:mutable)