scsh-0.5/scsh/char-set.scm

349 lines
11 KiB
Scheme

;;; -*-Scheme-*-
;;;
;;; Character Sets package
;;; - ported from MIT Scheme runtime
;;; by Brian D. Carlstrom
;;; - Rehacked & extended by Olin Shivers 6/98.
;;; This is not great code. Char sets are represented as 256-char
;;; strings. If char i is ASCII 0, then it isn't in the set; if char i
;;; is ASCII 1, then it is in the set.
;;; - Should be rewritten to use bit strings, or at least byte vecs.
;;; - Is ASCII/Latin-1 specific. Would certainly have to be rewritten
;;; for Unicode.
;;; - The standard character sets are not Latin-1 compliant, just ASCII.
;;; This code uses jar's DEFINE-RECORD-TYPE macro to define the char-set
;;; record type, because the scsh-standard DEFINE-RECORD form automatically
;;; defines a COPY-FOO function, which is not the one we want, being a shallow
;;; copy of the record fields.
;;; New dfns:
;;; (char-set= cs1 cs2 ...)
;;; (char-set<= cs1 cs2 ...)
;;; (char-set-fold kons knil cs)
;;; (char-set-for-each f cs)
;;; (char-set-copy cs)
;;; (char-set-size cs)
;;; char-set:printing (char-printing? c)
;;; char-set:blank (char-blank? c)
;;; char-set:control (char-control? c)
;;; char-set:hex-digit (char-hex-digit? c)
;;; char-set:ascii (char-ascii? c)
;;; char-set:empty
;;; char-set:full
;;; char-set-every? pred cs
;;; char-set-any pred cs
;;; char-set-adjoin cset char -> cset
;;; char-set-adjoin! cset char -> cset
;;; char-set-delete cset char -> cset
;;; char-set-delete! cset char -> cset
(define char:newline (ascii->char 13))
(define char:tab (ascii->char 9))
(define char:vtab (ascii->char 11))
(define char:page (ascii->char 12))
(define char:return (ascii->char 10))
(define char:space (ascii->char 32))
(define (string-copy s) (substring s 0 (string-length s)))
(define (string-fill-range! str lower upper ch)
(do ((index lower (+ index 1)))
((>= index upper) str)
(string-set! str index ch)))
(define (char-ascii? char)
(let ((maybe-ascii (char->ascii char)))
(and (<= 0 maybe-ascii 127) maybe-ascii)))
;;;; Character Sets
;(define-record char-set
; s) ; 256-char string; each char is either ASCII 0 or ASCII 1.
;;; Use jar's record macro.
(define-record-type char-set :char-set
(make-char-set s)
char-set?
(s char-set:s))
(define (char-set-copy cs) (make-char-set (string-copy (char-set:s cs))))
;;; The = and <= code is ugly because it's n-ary.
(define (char-set= cs1 . rest)
(let ((s1 (char-set:s cs1)))
(every (lambda (cs) (string=? s1 (char-set:s cs)))
rest)))
(define (char-set<= cs1 . rest)
(let lp ((s1 (char-set:s cs1))
(rest rest))
(or (not (pair? rest))
(let ((s2 (char-set:s (car rest)))
(rest (cdr rest)))
(let lp2 ((i 255))
(if (< i 0) (lp s2 rest)
(and (<= (char->ascii (string-ref s1 i))
(char->ascii (string-ref s2 i)))
(lp2 (- i 1)))))))))
(define (char-set-size cs)
(let ((s (char-set:s cs)))
(let lp ((i 255) (size 0))
(if (< i 0) size
(lp (- i 1)
(if (= 0 (char->ascii (string-ref s i))) size (+ size 1)))))))
(define (set-char-set cs in? . chars)
(let ((s (string-copy (char-set:s cs)))
(val (if in? (ascii->char 1) (ascii->char 0))))
(for-each (lambda (c) (string-set! s (char->ascii c) val))
chars)
(make-char-set s)))
(define (set-char-set! cs in? . chars)
(let ((s (char-set:s cs))
(val (if in? (ascii->char 1) (ascii->char 0))))
(for-each (lambda (c) (string-set! s (char->ascii c) val))
chars))
cs)
(define (char-set-adjoin cs . chars) (apply set-char-set cs #t chars))
(define (char-set-adjoin! cs . chars) (apply set-char-set! cs #t chars))
(define (char-set-delete cs . chars) (apply set-char-set cs #f chars))
(define (char-set-delete! cs . chars) (apply set-char-set! cs #f chars))
(define (char-set-for-each proc cs)
(let ((s (char-set:s cs)))
(let lp ((i 255))
(cond ((>= i 0)
(if (not (= 0 (char->ascii (string-ref s i))))
(proc (ascii->char i)))
(lp (- i 1)))))))
(define (char-set-fold kons knil cs)
(let ((s (char-set:s cs)))
(let lp ((i 255) (ans knil))
(if (< i 0) ans
(lp (- i 1)
(if (= 0 (char->ascii (string-ref s i)))
ans
(kons (ascii->char i) ans)))))))
(define reduce-char-set (deprecated-proc char-set-fold 'char-set-fold
"Use char-set-fold instead."))
(define (char-set-every? pred cs)
(let ((s (char-set:s cs)))
(let lp ((i 255))
(or (< i 0)
(if (= 0 (char->ascii (string-ref s i)))
(lp (- i 1))
(and (pred (ascii->char i))
(lp (- i 1))))))))
(define (char-set-any pred cs)
(let ((s (char-set:s cs)))
(let lp ((i 255))
(and (>= i 0)
(if (= 0 (char->ascii (string-ref s i)))
(lp (- i 1))
(or (pred (ascii->char i))
(lp (- i 1))))))))
(define (char-set . chars)
(chars->char-set chars))
(define (chars->char-set chars)
(let ((s (make-string 256 (ascii->char 0))))
(for-each (lambda (char)
(string-set! s (char->ascii char) (ascii->char 1)))
chars)
(make-char-set s)))
(define (string->char-set str)
(let ((s (make-string 256 (ascii->char 0))))
(do ((i (- (string-length str) 1) (- i 1)))
((< i 0) (make-char-set s))
(string-set! s (char->ascii (string-ref str i))
(ascii->char 1)))))
(define (ascii-range->char-set lower upper)
(let ((s (make-string 256 (ascii->char 0))))
(string-fill-range! s lower upper (ascii->char 1))
(make-char-set s)))
(define (predicate->char-set predicate)
(let ((s (make-string 256)))
(let lp ((i 255))
(if (>= i 0)
(begin (string-set! s i (if (predicate (ascii->char i))
(ascii->char 1)
(ascii->char 0)))
(lp (- i 1)))))
(make-char-set s)))
;;; {string, char, char-set, char predicate} -> char-set
(define (->char-set x)
(cond ((char-set? x) x)
((string? x) (string->char-set x))
((char? x) (char-set x))
((procedure? x) (predicate->char-set x))
(else (error "->char-set: Not a charset, string, char, or predicate."
x))))
;;;-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
(define (char-set-members cs)
(let ((s (char-set:s cs)))
(let lp ((i 255) (ans '()))
(if (< i 0) ans
(lp (- i 1)
(if (zero? (char->ascii (string-ref s i))) ans
(cons (ascii->char i) ans)))))))
;;; De-releasing CHAR-SET-MEMBER?
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; No other way to do it. MIT Scheme defines it (c-s-m? cset char); scsh 0.3
;;; defined it (c-s-m? char cset). MIT Scheme's arg order is not consistent
;;; with the MEMBER? procedure or common math notation, but they were here
;;; first, so I didn't want to just silently invert their arg order -- could
;;; break code. I ended up just choosing a new proc name that consistent with
;;; its arg order -- (CHAR-SET-CONTAINS? cset char).
(define (char-set-contains? cs char)
(not (zero? (char->ascii (string-ref (char-set:s cs)
(char->ascii char))))))
;;; This actually isn't exported. Just CYA.
(define (char-set-member? . args)
(error "CHAR-SET-MEMBER? is no longer provided. Use CHAR-SET-CONTAINS? instead."))
;;; Set algebra
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(define (char-set-invert cs)
(predicate->char-set (lambda (char)
(not (char-set-contains? cs char)))))
(define (char-set-union . csets)
(if (pair? csets)
(apply char-set-union! (char-set-copy (car csets)) (cdr csets))
char-set:empty))
(define (char-set-intersection . csets)
(if (pair? csets)
(apply char-set-intersection! (char-set-copy (car csets)) (cdr csets))
char-set:full))
(define (char-set-difference cs1 . csets)
(if (pair? csets)
(apply char-set-difference! (char-set-copy cs1) csets)
cs1))
;;; Linear set-algebraic ops
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; These guys are allowed, but not required, to side-effect their first
;;; argument when computing their result. In other words, you must use them
;;; as if they were completely functional, just like their non-! counterparts,
;;; and you must additionally ensure that their first arguments are "dead"
;;; at the point of call. In return, we promise a more efficient result, plus
;;; allowing you to always assume char-sets are unchangeable values.
;;; Apply P to each index and it's char in S: (P I C).
;;; Used by the intersection & difference.
(define (string-iter p s)
(let lp ((i (- (string-length s) 1)))
(cond ((>= i 0)
(p i (string-ref s i))
(lp (- i 1))))))
(define (char-set-invert! cset)
(let ((s (char-set:s cset)))
(string-iter (lambda (i c)
(string-set! s i (ascii->char (- 1 (char->ascii c)))))
s))
cset)
(define (char-set-union! cset1 . csets)
(let ((s (char-set:s cset1)))
(for-each (lambda (cset)
(char-set-for-each (lambda (c)
(string-set! s (char->ascii c)
(ascii->char 1)))
cset))
csets))
cset1)
(define (char-set-intersection! cset1 . csets)
(let ((s (char-set:s cset1)))
(for-each (lambda (cset)
(string-iter (lambda (i c)
(if (zero? (char->ascii c))
(string-set! s i (ascii->char 0))))
(char-set:s cset)))
csets))
cset1)
(define (char-set-difference! cset1 . csets)
(let ((s (char-set:s cset1)))
(for-each (lambda (cset)
(char-set-for-each (lambda (c)
(string-set! s (char->ascii c)
(ascii->char 0)))
cset))
csets))
cset1)
;;;; System Character Sets
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(define char-set:lower-case (ascii-range->char-set #x61 #x7B))
(define char-set:upper-case (ascii-range->char-set #x41 #x5B))
(define char-set:alphabetic
(char-set-union char-set:upper-case char-set:lower-case))
(define char-set:numeric (ascii-range->char-set #x30 #x3A))
(define char-set:alphanumeric
(char-set-union char-set:alphabetic char-set:numeric))
(define char-set:graphic (ascii-range->char-set #x21 #x7F))
(define char-set:printing (ascii-range->char-set #x20 #x7F))
(define char-set:whitespace (char-set char:tab char:newline char:vtab
char:page char:return char:space))
(define char-set:blank (char-set char:space char:tab))
(define char-set:control (char-set-union (ascii-range->char-set 0 32)
(char-set (ascii->char 127))))
(define char-set:punctuation
(string->char-set "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~"))
(define char-set:hex-digit (string->char-set "0123456789abcdefABCDEF"))
(define char-set:ascii (ascii-range->char-set 0 128))
(define char-set:empty (char-set))
(define char-set:full (char-set-invert char-set:empty))
(define (char-set->pred cs) (lambda (c) (char-set-contains? cs c)))
(define char-lower-case? (char-set->pred char-set:lower-case))
(define char-upper-case? (char-set->pred char-set:upper-case))
(define char-alphabetic? (char-set->pred char-set:alphabetic))
(define char-numeric? (char-set->pred char-set:numeric))
(define char-alphanumeric? (char-set->pred char-set:alphanumeric))
(define char-graphic? (char-set->pred char-set:graphic))
(define char-printing? (char-set->pred char-set:printing))
(define char-whitespace? (char-set->pred char-set:whitespace))
(define char-blank? (char-set->pred char-set:blank))
(define char-control? (char-set->pred char-set:control))
(define char-punctuation? (char-set->pred char-set:punctuation))
(define char-hex-digit? (char-set->pred char-set:hex-digit))
(define char-ascii? (char-set->pred char-set:ascii))