diff options
Diffstat (limited to 'strsrch.scm')
| -rw-r--r-- | strsrch.scm | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/strsrch.scm b/strsrch.scm index 68bcf0e..a6ab7e1 100644 --- a/strsrch.scm +++ b/strsrch.scm @@ -5,7 +5,7 @@ ; This code is in the public domain. ;;; Return the index of the first occurence of a-char in str, or #f -(define (string-index str a-char) +(define (strsrch:string-index str a-char) (let loop ((pos 0)) (cond ;; whole string has been searched, in vain @@ -40,7 +40,7 @@ (c2 (if (<= pat-len 1) #f (string-ref pattern 1)))) (cond ((not c1) 0) ; empty pattern, matches upfront - ((not c2) (string-index str c1)) ; one-char pattern + ((not c2) (strsrch:string-index str c1)) ; one-char pattern (else ; matching pattern of > two chars (let outer ((pos 0)) (cond @@ -66,16 +66,19 @@ (set! max-no-char (if (null? max-no-char) #f (car max-no-char))) (letrec ((no-chars-read 0) + (peeked? #f) (my-peek-char ; Return a peeked char or #f (lambda () (and (or (not (number? max-no-char)) (< no-chars-read max-no-char)) (let ((c (peek-char <input-port>))) - (and (not (eof-object? c)) - (if (procedure? max-no-char) - (not (max-no-char c)) - (not (eqv? max-no-char c))) - c))))) - (next-char (lambda () (read-char <input-port>) + (cond (peeked? c) + ((eof-object? c) #f) + ((procedure? max-no-char) + (set! peeked? #t) + (if (max-no-char c) #f c)) + ((eqv? max-no-char c) #f) + (else c)))))) + (next-char (lambda () (set! peeked? #f) (read-char <input-port>) (set! no-chars-read (+ 1 no-chars-read)))) (match-1st-char ; of the string str (lambda () |