793 lines
32 KiB
Scheme
793 lines
32 KiB
Scheme
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;pregexp.scm
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;Portable regular expressions for Scheme
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;Dorai Sitaram
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;http://www.ccs.neu.edu/~dorai
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;dorai AT ccs DOT neu DOT edu
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;Oct 2, 1999
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;;; ported to ikarus by Abdulaziz Ghuloum on Dec 19, 2007.
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;;; also added special cases for when the first argument to
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;;; any of these procedures is a known string at macro
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;;; expansion time.
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(library (pregexp)
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(export pregexp pregexp-match-positions pregexp-match
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pregexp-split pregexp-replace pregexp-replace*)
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(import (ikarus))
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(define *pregexp-version* 20071219) ;last change
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(define *pregexp-comment-char* #\;)
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(define *pregexp-nul-char-int* #\x0)
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(define *pregexp-return-char* #\return)
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(define *pregexp-tab-char* #\tab)
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(define *pregexp-space-sensitive?* #t)
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(define pregexp-reverse!
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;the useful reverse! isn't R5RS
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(lambda (s)
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(let loop ((s s) (r '()))
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(if (null? s) r
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(let ((d (cdr s)))
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(set-cdr! s r)
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(loop d s))))))
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(define pregexp-error
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;R5RS won't give me a portable error procedure.
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;modify this as needed
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(case-lambda
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[(who) (error who "an error occurred")]
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[(who msg . args) (apply error who (format "~a" msg) args)]))
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(define pregexp-read-pattern
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(lambda (s i n)
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(if (>= i n)
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(list
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(list ':or (list ':seq)) i)
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(let loop ((branches '()) (i i))
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(if (or (>= i n)
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(char=? (string-ref s i) #\)))
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(list (cons ':or (pregexp-reverse! branches)) i)
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(let ((vv (pregexp-read-branch
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s
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(if (char=? (string-ref s i) #\|) (+ i 1) i) n)))
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(loop (cons (car vv) branches) (cadr vv))))))))
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(define pregexp-read-branch
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(lambda (s i n)
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(let loop ((pieces '()) (i i))
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(cond ((>= i n)
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(list (cons ':seq (pregexp-reverse! pieces)) i))
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((let ((c (string-ref s i)))
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(or (char=? c #\|)
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(char=? c #\))))
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(list (cons ':seq (pregexp-reverse! pieces)) i))
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(else (let ((vv (pregexp-read-piece s i n)))
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(loop (cons (car vv) pieces) (cadr vv))))))))
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(define pregexp-read-piece
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(lambda (s i n)
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(let ((c (string-ref s i)))
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(case c
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((#\^) (list ':bos (+ i 1)))
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((#\$) (list ':eos (+ i 1)))
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((#\.) (pregexp-wrap-quantifier-if-any
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(list ':any (+ i 1)) s n))
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((#\[) (let ((i+1 (+ i 1)))
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(pregexp-wrap-quantifier-if-any
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(case (and (< i+1 n) (string-ref s i+1))
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((#\^)
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(let ((vv (pregexp-read-char-list s (+ i 2) n)))
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(list (list ':neg-char (car vv)) (cadr vv))))
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(else (pregexp-read-char-list s i+1 n)))
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s n)))
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((#\()
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(pregexp-wrap-quantifier-if-any
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(pregexp-read-subpattern s (+ i 1) n) s n))
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((#\\ )
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(pregexp-wrap-quantifier-if-any
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(cond ((pregexp-read-escaped-number s i n) =>
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(lambda (num-i)
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(list (list ':backref (car num-i)) (cadr num-i))))
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((pregexp-read-escaped-char s i n) =>
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(lambda (char-i)
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(list (car char-i) (cadr char-i))))
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(else (pregexp-error 'pregexp-read-piece 'backslash)))
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s n))
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(else
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(if (or *pregexp-space-sensitive?*
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(and (not (char-whitespace? c))
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(not (char=? c *pregexp-comment-char*))))
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(pregexp-wrap-quantifier-if-any
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(list c (+ i 1)) s n)
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(let loop ((i i) (in-comment? #f))
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(if (>= i n) (list ':empty i)
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(let ((c (string-ref s i)))
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(cond (in-comment?
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(loop (+ i 1)
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(not (char=? c #\newline))))
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((char-whitespace? c)
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(loop (+ i 1) #f))
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((char=? c *pregexp-comment-char*)
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(loop (+ i 1) #t))
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(else (list ':empty i))))))))))))
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(define pregexp-read-escaped-number
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(lambda (s i n)
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; s[i] = \
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(and (< (+ i 1) n) ;must have at least something following \
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(let ((c (string-ref s (+ i 1))))
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(and (char-numeric? c)
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(let loop ((i (+ i 2)) (r (list c)))
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(if (>= i n)
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(list (string->number
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(list->string (pregexp-reverse! r))) i)
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(let ((c (string-ref s i)))
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(if (char-numeric? c)
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(loop (+ i 1) (cons c r))
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(list (string->number
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(list->string (pregexp-reverse! r)))
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i))))))))))
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(define pregexp-read-escaped-char
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(lambda (s i n)
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; s[i] = \
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(and (< (+ i 1) n)
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(let ((c (string-ref s (+ i 1))))
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(case c
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((#\b) (list ':wbdry (+ i 2)))
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((#\B) (list ':not-wbdry (+ i 2)))
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((#\d) (list ':digit (+ i 2)))
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((#\D) (list '(:neg-char :digit) (+ i 2)))
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((#\n) (list #\newline (+ i 2)))
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((#\r) (list *pregexp-return-char* (+ i 2)))
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((#\s) (list ':space (+ i 2)))
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((#\S) (list '(:neg-char :space) (+ i 2)))
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((#\t) (list *pregexp-tab-char* (+ i 2)))
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((#\w) (list ':word (+ i 2)))
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((#\W) (list '(:neg-char :word) (+ i 2)))
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(else (list c (+ i 2))))))))
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(define pregexp-read-posix-char-class
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(lambda (s i n)
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; lbrack, colon already read
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(let ((neg? #f))
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(let loop ((i i) (r (list #\:)))
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(if (>= i n)
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(pregexp-error 'pregexp-read-posix-char-class)
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(let ((c (string-ref s i)))
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(cond ((char=? c #\^)
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(set! neg? #t)
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(loop (+ i 1) r))
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((char-alphabetic? c)
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(loop (+ i 1) (cons c r)))
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((char=? c #\:)
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(if (or (>= (+ i 1) n)
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(not (char=? (string-ref s (+ i 1)) #\])))
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(pregexp-error 'pregexp-read-posix-char-class)
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(let ((posix-class
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(string->symbol
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(list->string (pregexp-reverse! r)))))
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(list (if neg? (list ':neg-char posix-class)
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posix-class)
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(+ i 2)))))
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(else
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(pregexp-error 'pregexp-read-posix-char-class)))))))))
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(define pregexp-read-cluster-type
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(lambda (s i n)
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; s[i-1] = left-paren
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(let ((c (string-ref s i)))
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(case c
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((#\?)
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(let ((i (+ i 1)))
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(case (string-ref s i)
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((#\:) (list '() (+ i 1)))
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((#\=) (list '(:lookahead) (+ i 1)))
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((#\!) (list '(:neg-lookahead) (+ i 1)))
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((#\>) (list '(:no-backtrack) (+ i 1)))
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((#\<)
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(list (case (string-ref s (+ i 1))
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((#\=) '(:lookbehind))
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((#\!) '(:neg-lookbehind))
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(else (pregexp-error 'pregexp-read-cluster-type)))
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(+ i 2)))
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(else (let loop ((i i) (r '()) (inv? #f))
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(let ((c (string-ref s i)))
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(case c
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((#\-) (loop (+ i 1) r #t))
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((#\i) (loop (+ i 1)
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(cons (if inv? ':case-sensitive
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':case-insensitive) r) #f))
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((#\x)
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(set! *pregexp-space-sensitive?* inv?)
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(loop (+ i 1) r #f))
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((#\:) (list r (+ i 1)))
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(else (pregexp-error
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'pregexp-read-cluster-type)))))))))
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(else (list '(:sub) i))))))
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(define pregexp-read-subpattern
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(lambda (s i n)
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(let* ((remember-space-sensitive? *pregexp-space-sensitive?*)
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(ctyp-i (pregexp-read-cluster-type s i n))
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(ctyp (car ctyp-i))
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(i (cadr ctyp-i))
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(vv (pregexp-read-pattern s i n)))
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(set! *pregexp-space-sensitive?* remember-space-sensitive?)
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(let ((vv-re (car vv))
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(vv-i (cadr vv)))
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(if (and (< vv-i n)
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(char=? (string-ref s vv-i)
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#\)))
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(list
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(let loop ((ctyp ctyp) (re vv-re))
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(if (null? ctyp) re
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(loop (cdr ctyp)
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(list (car ctyp) re))))
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(+ vv-i 1))
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(pregexp-error 'pregexp-read-subpattern))))))
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(define pregexp-wrap-quantifier-if-any
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(lambda (vv s n)
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(let ((re (car vv)))
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(let loop ((i (cadr vv)))
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(if (>= i n) vv
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(let ((c (string-ref s i)))
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(if (and (char-whitespace? c) (not *pregexp-space-sensitive?*))
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(loop (+ i 1))
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(case c
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((#\* #\+ #\? #\{)
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(let* ((new-re (list ':between 'minimal?
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'at-least 'at-most re))
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(new-vv (list new-re 'next-i)))
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(case c
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((#\*) (set-car! (cddr new-re) 0)
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(set-car! (cdddr new-re) #f))
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((#\+) (set-car! (cddr new-re) 1)
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(set-car! (cdddr new-re) #f))
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((#\?) (set-car! (cddr new-re) 0)
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(set-car! (cdddr new-re) 1))
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((#\{) (let ((pq (pregexp-read-nums s (+ i 1) n)))
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(if (not pq)
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(pregexp-error
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'pregexp-wrap-quantifier-if-any
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'left-brace-must-be-followed-by-number))
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(set-car! (cddr new-re) (car pq))
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(set-car! (cdddr new-re) (cadr pq))
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(set! i (caddr pq)))))
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(let loop ((i (+ i 1)))
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(if (>= i n)
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(begin (set-car! (cdr new-re) #f)
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(set-car! (cdr new-vv) i))
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(let ((c (string-ref s i)))
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(cond ((and (char-whitespace? c)
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(not *pregexp-space-sensitive?*))
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(loop (+ i 1)))
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((char=? c #\?)
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(set-car! (cdr new-re) #t)
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(set-car! (cdr new-vv) (+ i 1)))
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(else (set-car! (cdr new-re) #f)
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(set-car! (cdr new-vv) i))))))
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new-vv))
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(else vv)))))))))
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;
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(define pregexp-read-nums
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(lambda (s i n)
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; s[i-1] = {
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; returns (p q k) where s[k] = }
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(let loop ((p '()) (q '()) (k i) (reading 1))
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(if (>= k n) (pregexp-error 'pregexp-read-nums))
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(let ((c (string-ref s k)))
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(cond ((char-numeric? c)
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(if (= reading 1)
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(loop (cons c p) q (+ k 1) 1)
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(loop p (cons c q) (+ k 1) 2)))
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((and (char-whitespace? c) (not *pregexp-space-sensitive?*))
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(loop p q (+ k 1) reading))
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((and (char=? c #\,) (= reading 1))
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(loop p q (+ k 1) 2))
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((char=? c #\})
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(let ((p (string->number (list->string (pregexp-reverse! p))))
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(q (string->number (list->string (pregexp-reverse! q)))))
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(cond ((and (not p) (= reading 1)) (list 0 #f k))
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((= reading 1) (list p p k))
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(else (list p q k)))))
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(else #f))))))
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(define pregexp-invert-char-list
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(lambda (vv)
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(set-car! (car vv) ':none-of-chars)
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vv))
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;
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(define pregexp-read-char-list
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(lambda (s i n)
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(let loop ((r '()) (i i))
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(if (>= i n)
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(pregexp-error 'pregexp-read-char-list
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'character-class-ended-too-soon)
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(let ((c (string-ref s i)))
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(case c
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((#\]) (if (null? r)
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(loop (cons c r) (+ i 1))
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(list (cons ':one-of-chars (pregexp-reverse! r))
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(+ i 1))))
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((#\\ )
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(let ((char-i (pregexp-read-escaped-char s i n)))
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(if char-i (loop (cons (car char-i) r) (cadr char-i))
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(pregexp-error 'pregexp-read-char-list 'backslash))))
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((#\-) (if (or (null? r)
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(let ((i+1 (+ i 1)))
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(and (< i+1 n)
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(char=? (string-ref s i+1) #\]))))
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(loop (cons c r) (+ i 1))
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(let ((c-prev (car r)))
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(if (char? c-prev)
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||
|
|
(loop (cons (list ':char-range c-prev
|
||
|
|
(string-ref s (+ i 1))) (cdr r))
|
||
|
|
(+ i 2))
|
||
|
|
(loop (cons c r) (+ i 1))))))
|
||
|
|
((#\[) (if (char=? (string-ref s (+ i 1)) #\:)
|
||
|
|
(let ((posix-char-class-i
|
||
|
|
(pregexp-read-posix-char-class s (+ i 2) n)))
|
||
|
|
(loop (cons (car posix-char-class-i) r)
|
||
|
|
(cadr posix-char-class-i)))
|
||
|
|
(loop (cons c r) (+ i 1))))
|
||
|
|
(else (loop (cons c r) (+ i 1)))))))))
|
||
|
|
|
||
|
|
|
||
|
|
;
|
||
|
|
|
||
|
|
(define pregexp-string-match
|
||
|
|
(lambda (s1 s i n sk fk)
|
||
|
|
(let ((n1 (string-length s1)))
|
||
|
|
(if (> n1 n) (fk)
|
||
|
|
(let loop ((j 0) (k i))
|
||
|
|
(cond ((>= j n1) (sk k))
|
||
|
|
((>= k n) (fk))
|
||
|
|
((char=? (string-ref s1 j) (string-ref s k))
|
||
|
|
(loop (+ j 1) (+ k 1)))
|
||
|
|
(else (fk))))))))
|
||
|
|
|
||
|
|
(define pregexp-char-word?
|
||
|
|
(lambda (c)
|
||
|
|
;too restrictive for Scheme but this
|
||
|
|
;is what \w is in most regexp notations
|
||
|
|
(or (char-alphabetic? c)
|
||
|
|
(char-numeric? c)
|
||
|
|
(char=? c #\_))))
|
||
|
|
|
||
|
|
(define pregexp-at-word-boundary?
|
||
|
|
(lambda (s i n)
|
||
|
|
(or (= i 0) (>= i n)
|
||
|
|
(let ((c/i (string-ref s i))
|
||
|
|
(c/i-1 (string-ref s (- i 1))))
|
||
|
|
(let ((c/i/w? (pregexp-check-if-in-char-class?
|
||
|
|
c/i ':word))
|
||
|
|
(c/i-1/w? (pregexp-check-if-in-char-class?
|
||
|
|
c/i-1 ':word)))
|
||
|
|
(or (and c/i/w? (not c/i-1/w?))
|
||
|
|
(and (not c/i/w?) c/i-1/w?)))))))
|
||
|
|
|
||
|
|
(define pregexp-check-if-in-char-class?
|
||
|
|
(lambda (c char-class)
|
||
|
|
(case char-class
|
||
|
|
((:any) (not (char=? c #\newline)))
|
||
|
|
;
|
||
|
|
((:alnum) (or (char-alphabetic? c) (char-numeric? c)))
|
||
|
|
((:alpha) (char-alphabetic? c))
|
||
|
|
((:ascii) (< (char->integer c) 128))
|
||
|
|
((:blank) (or (char=? c #\space) (char=? c *pregexp-tab-char*)))
|
||
|
|
((:cntrl) (< (char->integer c) 32))
|
||
|
|
((:digit) (char-numeric? c))
|
||
|
|
((:graph) (and (>= (char->integer c) 32)
|
||
|
|
(not (char-whitespace? c))))
|
||
|
|
((:lower) (char-lower-case? c))
|
||
|
|
((:print) (>= (char->integer c) 32))
|
||
|
|
((:punct) (and (>= (char->integer c) 32)
|
||
|
|
(not (char-whitespace? c))
|
||
|
|
(not (char-alphabetic? c))
|
||
|
|
(not (char-numeric? c))))
|
||
|
|
((:space) (char-whitespace? c))
|
||
|
|
((:upper) (char-upper-case? c))
|
||
|
|
((:word) (or (char-alphabetic? c)
|
||
|
|
(char-numeric? c)
|
||
|
|
(char=? c #\_)))
|
||
|
|
((:xdigit) (or (char-numeric? c)
|
||
|
|
(char-ci=? c #\a) (char-ci=? c #\b)
|
||
|
|
(char-ci=? c #\c) (char-ci=? c #\d)
|
||
|
|
(char-ci=? c #\e) (char-ci=? c #\f)))
|
||
|
|
(else (pregexp-error 'pregexp-check-if-in-char-class?)))))
|
||
|
|
|
||
|
|
(define pregexp-list-ref
|
||
|
|
(lambda (s i)
|
||
|
|
;like list-ref but returns #f if index is
|
||
|
|
;out of bounds
|
||
|
|
(let loop ((s s) (k 0))
|
||
|
|
(cond ((null? s) #f)
|
||
|
|
((= k i) (car s))
|
||
|
|
(else (loop (cdr s) (+ k 1)))))))
|
||
|
|
|
||
|
|
;re is a compiled regexp. It's a list that can't be
|
||
|
|
;nil. pregexp-match-positions-aux returns a 2-elt list whose
|
||
|
|
;car is the string-index following the matched
|
||
|
|
;portion and whose cadr contains the submatches.
|
||
|
|
;The proc returns false if there's no match.
|
||
|
|
|
||
|
|
;Am spelling loop- as loup- because these shouldn't
|
||
|
|
;be translated into CL loops by scm2cl (although
|
||
|
|
;they are tail-recursive in Scheme)
|
||
|
|
|
||
|
|
(define pregexp-make-backref-list
|
||
|
|
(lambda (re)
|
||
|
|
(let sub ((re re))
|
||
|
|
(if (pair? re)
|
||
|
|
(let ((car-re (car re))
|
||
|
|
(sub-cdr-re (sub (cdr re))))
|
||
|
|
(if (eqv? car-re ':sub)
|
||
|
|
(cons (cons re #f) sub-cdr-re)
|
||
|
|
(append (sub car-re) sub-cdr-re)))
|
||
|
|
'()))))
|
||
|
|
|
||
|
|
(define pregexp-match-positions-aux
|
||
|
|
(lambda (re s sn start n i)
|
||
|
|
(let ((identity (lambda (x) x))
|
||
|
|
(backrefs (pregexp-make-backref-list re))
|
||
|
|
(case-sensitive? #t))
|
||
|
|
(let sub ((re re) (i i) (sk identity) (fk (lambda () #f)))
|
||
|
|
;(printf "sub ~s ~s\n" i re)
|
||
|
|
(cond ((eqv? re ':bos)
|
||
|
|
;(if (= i 0) (sk i) (fk))
|
||
|
|
(if (= i start) (sk i) (fk))
|
||
|
|
)
|
||
|
|
((eqv? re ':eos)
|
||
|
|
;(if (>= i sn) (sk i) (fk))
|
||
|
|
(if (>= i n) (sk i) (fk))
|
||
|
|
)
|
||
|
|
((eqv? re ':empty)
|
||
|
|
(sk i))
|
||
|
|
((eqv? re ':wbdry)
|
||
|
|
(if (pregexp-at-word-boundary? s i n)
|
||
|
|
(sk i)
|
||
|
|
(fk)))
|
||
|
|
((eqv? re ':not-wbdry)
|
||
|
|
(if (pregexp-at-word-boundary? s i n)
|
||
|
|
(fk)
|
||
|
|
(sk i)))
|
||
|
|
((and (char? re) (< i n))
|
||
|
|
;(printf "bingo\n")
|
||
|
|
(if ((if case-sensitive? char=? char-ci=?)
|
||
|
|
(string-ref s i) re)
|
||
|
|
(sk (+ i 1)) (fk)))
|
||
|
|
((and (not (pair? re)) (< i n))
|
||
|
|
(if (pregexp-check-if-in-char-class?
|
||
|
|
(string-ref s i) re)
|
||
|
|
(sk (+ i 1)) (fk)))
|
||
|
|
((and (pair? re) (eqv? (car re) ':char-range) (< i n))
|
||
|
|
(let ((c (string-ref s i)))
|
||
|
|
(if (let ((c< (if case-sensitive? char<=? char-ci<=?)))
|
||
|
|
(and (c< (cadr re) c)
|
||
|
|
(c< c (caddr re))))
|
||
|
|
(sk (+ i 1)) (fk))))
|
||
|
|
((pair? re)
|
||
|
|
(case (car re)
|
||
|
|
((:char-range)
|
||
|
|
(if (>= i n) (fk)
|
||
|
|
(pregexp-error 'pregexp-match-positions-aux)))
|
||
|
|
((:one-of-chars)
|
||
|
|
(if (>= i n) (fk)
|
||
|
|
(let loup-one-of-chars ((chars (cdr re)))
|
||
|
|
(if (null? chars) (fk)
|
||
|
|
(sub (car chars) i sk
|
||
|
|
(lambda ()
|
||
|
|
(loup-one-of-chars (cdr chars))))))))
|
||
|
|
((:neg-char)
|
||
|
|
(if (>= i n) (fk)
|
||
|
|
(sub (cadr re) i
|
||
|
|
(lambda (i1) (fk))
|
||
|
|
(lambda () (sk (+ i 1))))))
|
||
|
|
((:seq)
|
||
|
|
(let loup-seq ((res (cdr re)) (i i))
|
||
|
|
(if (null? res) (sk i )
|
||
|
|
(sub (car res) i
|
||
|
|
(lambda (i1 )
|
||
|
|
(loup-seq (cdr res) i1 ))
|
||
|
|
fk))))
|
||
|
|
((:or)
|
||
|
|
(let loup-or ((res (cdr re)))
|
||
|
|
(if (null? res) (fk)
|
||
|
|
(sub (car res) i
|
||
|
|
(lambda (i1 )
|
||
|
|
(or (sk i1 )
|
||
|
|
(loup-or (cdr res))))
|
||
|
|
(lambda () (loup-or (cdr res)))))))
|
||
|
|
((:backref)
|
||
|
|
(let* ((c (pregexp-list-ref backrefs (cadr re)))
|
||
|
|
(backref
|
||
|
|
(cond (c => cdr)
|
||
|
|
(else
|
||
|
|
(pregexp-error 'pregexp-match-positions-aux
|
||
|
|
'non-existent-backref re)
|
||
|
|
#f))))
|
||
|
|
(if backref
|
||
|
|
(pregexp-string-match
|
||
|
|
(substring s (car backref) (cdr backref))
|
||
|
|
s i n (lambda (i) (sk i)) fk)
|
||
|
|
(sk i))))
|
||
|
|
((:sub)
|
||
|
|
(sub (cadr re) i
|
||
|
|
(lambda (i1)
|
||
|
|
(set-cdr! (assv re backrefs) (cons i i1))
|
||
|
|
(sk i1)) fk))
|
||
|
|
((:lookahead)
|
||
|
|
(let ((found-it?
|
||
|
|
(sub (cadr re) i
|
||
|
|
identity (lambda () #f))))
|
||
|
|
(if found-it? (sk i) (fk))))
|
||
|
|
((:neg-lookahead)
|
||
|
|
(let ((found-it?
|
||
|
|
(sub (cadr re) i
|
||
|
|
identity (lambda () #f))))
|
||
|
|
(if found-it? (fk) (sk i))))
|
||
|
|
((:lookbehind)
|
||
|
|
(let ((n-actual n) (sn-actual sn))
|
||
|
|
(set! n i) (set! sn i)
|
||
|
|
(let ((found-it?
|
||
|
|
(sub (list ':seq '(:between #f 0 #f :any)
|
||
|
|
(cadr re) ':eos) 0
|
||
|
|
identity (lambda () #f))))
|
||
|
|
(set! n n-actual) (set! sn sn-actual)
|
||
|
|
(if found-it? (sk i) (fk)))))
|
||
|
|
((:neg-lookbehind)
|
||
|
|
(let ((n-actual n) (sn-actual sn))
|
||
|
|
(set! n i) (set! sn i)
|
||
|
|
(let ((found-it?
|
||
|
|
(sub (list ':seq '(:between #f 0 #f :any)
|
||
|
|
(cadr re) ':eos) 0
|
||
|
|
identity (lambda () #f))))
|
||
|
|
(set! n n-actual) (set! sn sn-actual)
|
||
|
|
(if found-it? (fk) (sk i)))))
|
||
|
|
((:no-backtrack)
|
||
|
|
(let ((found-it? (sub (cadr re) i
|
||
|
|
identity (lambda () #f))))
|
||
|
|
(if found-it?
|
||
|
|
(sk found-it?)
|
||
|
|
(fk))))
|
||
|
|
((:case-sensitive :case-insensitive)
|
||
|
|
(let ((old case-sensitive?))
|
||
|
|
(set! case-sensitive?
|
||
|
|
(eqv? (car re) ':case-sensitive))
|
||
|
|
(sub (cadr re) i
|
||
|
|
(lambda (i1)
|
||
|
|
(set! case-sensitive? old)
|
||
|
|
(sk i1))
|
||
|
|
(lambda ()
|
||
|
|
(set! case-sensitive? old)
|
||
|
|
(fk)))))
|
||
|
|
((:between)
|
||
|
|
(let* ((maximal? (not (cadr re)))
|
||
|
|
(p (caddr re))
|
||
|
|
(q (cadddr re))
|
||
|
|
(could-loop-infinitely? (and maximal? (not q)))
|
||
|
|
(re (car (cddddr re))))
|
||
|
|
(let loup-p ((k 0) (i i) )
|
||
|
|
(if (< k p)
|
||
|
|
(sub re i
|
||
|
|
(lambda (i1 )
|
||
|
|
(if (and could-loop-infinitely?
|
||
|
|
(= i1 i))
|
||
|
|
(pregexp-error
|
||
|
|
'pregexp-match-positions-aux
|
||
|
|
'greedy-quantifier-operand-could-be-empty))
|
||
|
|
(loup-p (+ k 1) i1 ))
|
||
|
|
fk)
|
||
|
|
(let ((q (and q (- q p))))
|
||
|
|
(let loup-q ((k 0) (i i))
|
||
|
|
(let ((fk (lambda ()
|
||
|
|
(sk i ))))
|
||
|
|
(if (and q (>= k q)) (fk)
|
||
|
|
(if maximal?
|
||
|
|
(sub re i
|
||
|
|
(lambda (i1)
|
||
|
|
(if (and could-loop-infinitely?
|
||
|
|
(= i1 i))
|
||
|
|
(pregexp-error
|
||
|
|
'pregexp-match-positions-aux
|
||
|
|
'greedy-quantifier-operand-could-be-empty))
|
||
|
|
(or (loup-q (+ k 1) i1)
|
||
|
|
(fk)))
|
||
|
|
fk)
|
||
|
|
(or (fk)
|
||
|
|
(sub re i
|
||
|
|
(lambda (i1)
|
||
|
|
(loup-q (+ k 1) i1))
|
||
|
|
fk)))))))))))
|
||
|
|
(else (pregexp-error 'pregexp-match-positions-aux))))
|
||
|
|
((>= i n) (fk))
|
||
|
|
(else (pregexp-error 'pregexp-match-positions-aux))))
|
||
|
|
;(printf "done\n")
|
||
|
|
(let ((backrefs (map cdr backrefs)))
|
||
|
|
(and (car backrefs) backrefs)))))
|
||
|
|
|
||
|
|
(define pregexp-replace-aux
|
||
|
|
(lambda (str ins n backrefs)
|
||
|
|
(let loop ((i 0) (r ""))
|
||
|
|
(if (>= i n) r
|
||
|
|
(let ((c (string-ref ins i)))
|
||
|
|
(if (char=? c #\\ )
|
||
|
|
(let* ((br-i (pregexp-read-escaped-number ins i n))
|
||
|
|
(br (if br-i (car br-i)
|
||
|
|
(if (char=? (string-ref ins (+ i 1)) #\&) 0
|
||
|
|
#f)))
|
||
|
|
(i (if br-i (cadr br-i)
|
||
|
|
(if br (+ i 2)
|
||
|
|
(+ i 1)))))
|
||
|
|
(if (not br)
|
||
|
|
(let ((c2 (string-ref ins i)))
|
||
|
|
(loop (+ i 1)
|
||
|
|
(if (char=? c2 #\$) r
|
||
|
|
(string-append r (string c2)))))
|
||
|
|
(loop i
|
||
|
|
(let ((backref (pregexp-list-ref backrefs br)))
|
||
|
|
(if backref
|
||
|
|
(string-append r
|
||
|
|
(substring str (car backref) (cdr backref)))
|
||
|
|
r)))))
|
||
|
|
(loop (+ i 1) (string-append r (string c)))))))))
|
||
|
|
|
||
|
|
(define pregexp-proc
|
||
|
|
(let ([pregexp
|
||
|
|
(lambda (s)
|
||
|
|
(set! *pregexp-space-sensitive?* #t) ;in case it got corrupted
|
||
|
|
(list ':sub (car (pregexp-read-pattern s 0 (string-length s)))))])
|
||
|
|
pregexp))
|
||
|
|
|
||
|
|
(define-syntax pregexp
|
||
|
|
(lambda (x) ;;; aziz's touch
|
||
|
|
(syntax-case x ()
|
||
|
|
[(_ str)
|
||
|
|
(string? (syntax->datum #'str))
|
||
|
|
#'(let-syntax ([foo
|
||
|
|
(lambda (t)
|
||
|
|
(list #'quote (pregexp-proc str)))])
|
||
|
|
foo)]
|
||
|
|
[(_ args ...) #'(pregexp-proc args ...)]
|
||
|
|
[id (identifier? #'id) #'pregexp-proc])))
|
||
|
|
|
||
|
|
|
||
|
|
(define-syntax define-regexp-proc
|
||
|
|
(lambda (stx)
|
||
|
|
(syntax-case stx ()
|
||
|
|
[(_ name expr)
|
||
|
|
(with-syntax ([(name^) (generate-temporaries (list #'name))])
|
||
|
|
#'(begin
|
||
|
|
(define name^ expr)
|
||
|
|
(define-syntax name
|
||
|
|
(lambda (x)
|
||
|
|
(syntax-case x ()
|
||
|
|
[(_ str args (... ...)) (string? #'str)
|
||
|
|
#'(name^ (pregexp str) args (... ...))]
|
||
|
|
[(_ args (... ...))
|
||
|
|
#'(name^ args (... ...))]
|
||
|
|
[id (identifier? #'id) #'name^])))))])))
|
||
|
|
|
||
|
|
|
||
|
|
(define-regexp-proc pregexp-match-positions
|
||
|
|
(lambda (pat str . opt-args)
|
||
|
|
(cond ((string? pat) (set! pat (pregexp pat)))
|
||
|
|
((pair? pat) #t)
|
||
|
|
(else (pregexp-error 'pregexp-match-positions
|
||
|
|
'pattern-must-be-compiled-or-string-regexp
|
||
|
|
pat)))
|
||
|
|
(let* ((str-len (string-length str))
|
||
|
|
(start (if (null? opt-args) 0
|
||
|
|
(let ((start (car opt-args)))
|
||
|
|
(set! opt-args (cdr opt-args))
|
||
|
|
start)))
|
||
|
|
(end (if (null? opt-args) str-len
|
||
|
|
(car opt-args))))
|
||
|
|
(let loop ((i start))
|
||
|
|
(and (<= i end)
|
||
|
|
(or (pregexp-match-positions-aux
|
||
|
|
pat str str-len start end i)
|
||
|
|
(loop (+ i 1))))))))
|
||
|
|
|
||
|
|
|
||
|
|
(define-regexp-proc pregexp-match
|
||
|
|
(lambda (pat str . opt-args)
|
||
|
|
(let ((ix-prs (apply pregexp-match-positions pat str opt-args)))
|
||
|
|
(and ix-prs
|
||
|
|
(map
|
||
|
|
(lambda (ix-pr)
|
||
|
|
(and ix-pr
|
||
|
|
(substring str (car ix-pr) (cdr ix-pr))))
|
||
|
|
ix-prs)))))
|
||
|
|
|
||
|
|
(define-regexp-proc pregexp-split
|
||
|
|
(lambda (pat str)
|
||
|
|
;split str into substrings, using pat as delimiter
|
||
|
|
(let ((n (string-length str))
|
||
|
|
;;; aziz
|
||
|
|
(pat (if (string? pat) (pregexp pat) pat)))
|
||
|
|
(let loop ((i 0) (r '()) (picked-up-one-undelimited-char? #f))
|
||
|
|
(cond ((>= i n) (pregexp-reverse! r))
|
||
|
|
((pregexp-match-positions pat str i n)
|
||
|
|
=>
|
||
|
|
(lambda (y)
|
||
|
|
(let ((jk (car y)))
|
||
|
|
(let ((j (car jk)) (k (cdr jk)))
|
||
|
|
;(printf "j = ~a; k = ~a; i = ~a~n" j k i)
|
||
|
|
(cond ((= j k)
|
||
|
|
;(printf "producing ~s~n" (substring str i (+ j 1)))
|
||
|
|
(loop (+ k 1)
|
||
|
|
(cons (substring str i (+ j 1)) r) #t))
|
||
|
|
((and (= j i) picked-up-one-undelimited-char?)
|
||
|
|
(loop k r #f))
|
||
|
|
(else
|
||
|
|
;(printf "producing ~s~n" (substring str i j))
|
||
|
|
(loop k (cons (substring str i j) r) #f)))))))
|
||
|
|
(else (loop n (cons (substring str i n) r) #f)))))))
|
||
|
|
|
||
|
|
|
||
|
|
(define-regexp-proc pregexp-replace
|
||
|
|
(lambda (pat str ins)
|
||
|
|
(let* ((n (string-length str))
|
||
|
|
(pp (pregexp-match-positions pat str 0 n)))
|
||
|
|
(if (not pp) str
|
||
|
|
(let ((ins-len (string-length ins))
|
||
|
|
(m-i (caar pp))
|
||
|
|
(m-n (cdar pp)))
|
||
|
|
(string-append
|
||
|
|
(substring str 0 m-i)
|
||
|
|
(pregexp-replace-aux str ins ins-len pp)
|
||
|
|
(substring str m-n n)))))))
|
||
|
|
|
||
|
|
(define-regexp-proc pregexp-replace*
|
||
|
|
(lambda (pat str ins)
|
||
|
|
;return str with every occurrence of pat
|
||
|
|
;replaced by ins
|
||
|
|
(let ((pat (if (string? pat) (pregexp pat) pat))
|
||
|
|
(n (string-length str))
|
||
|
|
(ins-len (string-length ins)))
|
||
|
|
(let loop ((i 0) (r ""))
|
||
|
|
;i = index in str to start replacing from
|
||
|
|
;r = already calculated prefix of answer
|
||
|
|
(if (>= i n) r
|
||
|
|
(let ((pp (pregexp-match-positions pat str i n)))
|
||
|
|
(if (not pp)
|
||
|
|
(if (= i 0)
|
||
|
|
;this implies pat didn't match str at
|
||
|
|
;all, so let's return original str
|
||
|
|
str
|
||
|
|
;else: all matches already found and
|
||
|
|
;replaced in r, so let's just
|
||
|
|
;append the rest of str
|
||
|
|
(string-append
|
||
|
|
r (substring str i n)))
|
||
|
|
(loop (cdar pp)
|
||
|
|
(string-append
|
||
|
|
r
|
||
|
|
(substring str i (caar pp))
|
||
|
|
(pregexp-replace-aux str ins ins-len pp))))))))))
|
||
|
|
|
||
|
|
(define pregexp-quote
|
||
|
|
(lambda (s)
|
||
|
|
(let loop ((i (- (string-length s) 1)) (r '()))
|
||
|
|
(if (< i 0) (list->string r)
|
||
|
|
(loop (- i 1)
|
||
|
|
(let ((c (string-ref s i)))
|
||
|
|
(if (memv c '(#\\ #\. #\? #\* #\+ #\| #\^ #\$
|
||
|
|
#\[ #\] #\{ #\} #\( #\)))
|
||
|
|
(cons #\\ (cons c r))
|
||
|
|
(cons c r))))))))
|
||
|
|
|
||
|
|
)
|