chibi-scheme/lib/scheme/char/full.scm
2020-06-04 22:08:07 +09:00

128 lines
4.5 KiB
Scheme

(define (char-alphabetic? ch) (char-set-contains? char-set:letter ch))
(define (char-lower-case? ch) (char-set-contains? char-set:lower-case ch))
(define (char-upper-case? ch) (char-set-contains? char-set:upper-case ch))
(define (char-numeric? ch) (char-set-contains? char-set:digit ch))
(define (char-whitespace? ch) (char-set-contains? char-set:whitespace ch))
(define (bsearch-kv vec n lo hi)
(and (<= lo hi)
(let* ((mid (+ lo (* (quotient (- hi lo) 4) 2)))
(m (vector-ref vec mid)))
(cond
((= n m)
(integer->char (vector-ref vec (+ mid 1))))
((< n m)
(bsearch-kv vec n lo (- mid 2)))
(else
(bsearch-kv vec n (+ mid 2) hi))))))
(define (char-downcase ch)
(let ((n (char->integer ch)))
(let lp ((ls char-downcase-offsets))
(cond
((null? ls)
(or (bsearch-kv char-downcase-map n 0
(- (vector-length char-downcase-map) 2))
ch))
((iset-contains? (caar ls) n)
(integer->char (+ n (cdar ls))))
(else (lp (cdr ls)))))))
(define (char-upcase ch)
(let ((n (char->integer ch)))
(let lp ((ls char-downcase-offsets))
(cond
((null? ls)
(or (bsearch-kv char-upcase-map n 0
(- (vector-length char-upcase-map) 2))
ch))
((iset-contains? (caar ls) (- n (cdar ls)))
(integer->char (- n (cdar ls))))
(else (lp (cdr ls)))))))
(define (char-foldcase ch)
(or (bsearch-kv char-foldcase-map (char->integer ch) 0
(- (vector-length char-foldcase-map) 2))
ch))
(define (char-cmp-ci op a ls)
(let lp ((op op) (a (char->integer (char-foldcase a))) (ls ls))
(if (null? ls)
#t
(let ((b (char->integer (char-downcase (car ls)))))
(and (op a b) (lp op b (cdr ls)))))))
(define (char-ci=? a . ls) (char-cmp-ci = a ls))
(define (char-ci<? a . ls) (char-cmp-ci < a ls))
(define (char-ci>? a . ls) (char-cmp-ci > a ls))
(define (char-ci<=? a . ls) (char-cmp-ci <= a ls))
(define (char-ci>=? a . ls) (char-cmp-ci >= a ls))
(define (char-get-special-case ch off)
(let ((i (char->integer ch)))
(let lp ((a 0) (b (vector-length special-cases)))
(let* ((mid (+ a (quotient (- b a) 2)))
(vec (vector-ref special-cases mid))
(val (vector-ref vec 0)))
(cond ((< i val) (and (< mid b) (lp a mid)))
((> i val) (and (> mid a) (lp mid b)))
(else
(vector-ref vec (if (>= off (vector-length vec)) 1 off))))))))
(define (call-with-output-string proc)
(let ((out (open-output-string)))
(proc out)
(get-output-string out)))
(define (string-down-or-fold-case str fold?)
(call-with-output-string
(lambda (out)
(let ((in (open-input-string str)))
(let lp ()
(let ((ch (read-char in)))
(cond
((not (eof-object? ch))
(cond
((and (not fold?) (eqv? ch #\x03A3)) ;; sigma
(let ((ch2 (peek-char in)))
(write-char
(if (or (eof-object? ch2)
(not (char-set-contains? char-set:letter ch2)))
#\x03C2
#\x03C3)
out)))
((char-get-special-case ch (if fold? 4 1))
=> (lambda (s) (write-string s out)))
(else
(write-char (if fold? (char-foldcase ch) (char-downcase ch))
out)))
(lp)))))))))
(define (string-downcase str) (string-down-or-fold-case str #f))
(define (string-foldcase str) (string-down-or-fold-case str #t))
(define (string-upcase str)
(call-with-output-string
(lambda (out)
(string-for-each
(lambda (ch)
(write-string (if (memv ch '(#\x03C2 #\x03C3))
#\x03A3
(or (char-get-special-case ch 3)
(char-upcase ch)))
out))
str))))
(define (string-cmp-ci op a ls)
(let lp ((op op) (a (string-foldcase a)) (ls ls))
(if (null? ls)
#t
(let ((b (string-foldcase (car ls))))
(and (op a b) (lp op b (cdr ls)))))))
(define (string-ci=? a . ls) (string-cmp-ci string=? a ls))
(define (string-ci<? a . ls) (string-cmp-ci string<? a ls))
(define (string-ci>? a . ls) (string-cmp-ci string>? a ls))
(define (string-ci<=? a . ls) (string-cmp-ci string<=? a ls))
(define (string-ci>=? a . ls) (string-cmp-ci string>=? a ls))