;;;; Programmer: Kevin M. Rosenberg
;;;; Date Started: Apr 2000
;;;;
-;;;; $Id: strings.lisp,v 1.4 2002/12/26 11:57:07 kevin Exp $
+;;;; $Id$
;;;;
-;;;; This file, part of KMRCL, is Copyright (c) 2002 by Kevin M. Rosenberg
+;;;; This file, part of KMRCL, is Copyright (c) 2002-2006 by Kevin M. Rosenberg
;;;;
;;;; KMRCL users are granted the rights to distribute and use this software
;;;; as governed by the terms of the Lisp Lesser GNU Public License
;;;; *************************************************************************
-(in-package :kmrcl)
-(declaim (optimize (speed 3) (safety 1) (compilation-speed 0) (debug 3)))
+(in-package #:kmrcl)
;;; Strings
(defun count-string-words (str)
(declare (simple-string str)
- (optimize (speed 3) (safety 0)))
+ (optimize (speed 3) (safety 0) (space 0)))
(let ((n-words 0)
(in-word nil))
(declare (fixnum n-words))
- (dotimes (i (length str))
- (let ((ch (char str i)))
- (declare (character ch))
- (if (alphanumericp ch)
- (unless in-word
- (incf n-words)
- (setq in-word t))
- (setq in-word nil))))
- n-words))
-
-#+excl
-(defun delimited-string-to-list (string &optional (separator #\space))
- (excl:delimited-string-to-list string separator))
-
-#-excl
-(defun delimited-string-to-list (sequence &optional (separator #\space))
- "Split a string by a delimitor"
- (loop
- with start = 0
- for end = (position separator sequence :start start)
- collect (subseq sequence start end)
- until (null end)
- do
- (setf start (1+ end))))
-
-#+excl
-(defun list-to-delimited-string (list &optional (separator #\space))
- (excl:list-to-delimited-string list separator))
-
-#-excl
-(defun list-to-delimited-string (list &optional (separator #\space))
- (let ((output (when list (format nil "~A" (car list)))))
- (dolist (obj (rest list))
- (setq output (concatenate 'string output
- (format nil "~A" separator)
- (format nil "~A" obj))))
- output))
+ (do* ((len (length str))
+ (i 0 (1+ i)))
+ ((= i len) n-words)
+ (declare (fixnum i))
+ (if (alphanumericp (schar str i))
+ (unless in-word
+ (incf n-words)
+ (setq in-word t))
+ (setq in-word nil)))))
+
+;; From Larry Hunter with modifications
+(defun position-char (char string start max)
+ (declare (optimize (speed 3) (safety 0) (space 0))
+ (fixnum start max) (simple-string string))
+ (do* ((i start (1+ i)))
+ ((= i max) nil)
+ (declare (fixnum i))
+ (when (char= char (schar string i)) (return i))))
+
+(defun position-not-char (char string start max)
+ (declare (optimize (speed 3) (safety 0) (space 0))
+ (fixnum start max) (simple-string string))
+ (do* ((i start (1+ i)))
+ ((= i max) nil)
+ (declare (fixnum i))
+ (when (char/= char (schar string i)) (return i))))
+
+(defun delimited-string-to-list (string &optional (separator #\space)
+ skip-terminal)
+ "split a string with delimiter"
+ (declare (optimize (speed 3) (safety 0) (space 0) (compilation-speed 0))
+ (type string string)
+ (type character separator))
+ (do* ((len (length string))
+ (output '())
+ (pos 0)
+ (end (position-char separator string pos len)
+ (position-char separator string pos len)))
+ ((null end)
+ (if (< pos len)
+ (push (subseq string pos) output)
+ (when (or (not skip-terminal) (zerop len))
+ (push "" output)))
+ (nreverse output))
+ (declare (type fixnum pos len)
+ (type (or null fixnum) end))
+ (push (subseq string pos end) output)
+ (setq pos (1+ end))))
+
+
+(defun list-to-delimited-string (list &optional (separator " "))
+ (format nil (concatenate 'string "~{~A~^" (string separator) "~}") list))
(defun string-invert (str)
"Invert case of a string"
(let ((up nil) (down nil))
(block skip
(loop for char of-type character across str do
- (cond ((upper-case-p char) (if down (return-from skip str) (setf up t)))
- ((lower-case-p char) (if up (return-from skip str) (setf down t)))))
+ (cond ((upper-case-p char)
+ (if down (return-from skip str) (setf up t)))
+ ((lower-case-p char)
+ (if up (return-from skip str) (setf down t)))))
(if up (string-downcase str) (string-upcase str)))))
(defun add-sql-quotes (s)
(defun escape-backslashes (s)
(substitute-string-for-char s #\\ "\\\\"))
-(defun substitute-string-for-char (procstr match-char subst-str)
+(defun substitute-string-for-char (procstr match-char subst-str)
"Substitutes a string for a single matching character of a string"
- (let ((pos (position match-char procstr)))
- (if pos
- (concatenate 'string
- (subseq procstr 0 pos) subst-str
- (substitute-string-for-char (subseq procstr (1+ pos)) match-char subst-str))
- procstr)))
+ (substitute-chars-strings procstr (list (cons match-char subst-str))))
(defun string-substitute (string substring replacement-string)
"String substitute by Larry Hunter. Obtained from Google"
replacement-string))
(setq last-end (+ next-start substring-length)))))
-
(defun string-trim-last-character (s)
-"Return the string less the last character"
- (subseq s 0 (1- (length s))))
+ "Return the string less the last character"
+ (let ((len (length s)))
+ (if (plusp len)
+ (subseq s 0 (1- len))
+ s)))
+
+(defun nstring-trim-last-character (s)
+ "Return the string less the last character"
+ (let ((len (length s)))
+ (if (plusp len)
+ (nsubseq s 0 (1- len))
+ s)))
(defun string-hash (str &optional (bitmask 65535))
(let ((hash 0))
(setq hash (+ hash (char-code (char str i)))))
(logand hash bitmask)))
-(defun string-not-null? (str)
- (and str (not (zerop (length str)))))
-
-(defun whitespace? (c)
- (declare (character c))
- (declare (optimize (speed 3) (safety 0)))
- (or (char= c #\Space) (char= c #\Tab) (char= c #\Return) (char= c #\Linefeed)))
+(defun is-string-empty (str)
+ (zerop (length str)))
+
+(defvar *whitespace-chars* '(#\space #\tab #\return #\linefeed
+ #+allegro #\%space
+ #+lispworks #\No-Break-Space))
-(defun not-whitespace? (c)
- (not (whitespace? c)))
+(defun is-char-whitespace (c)
+ (declare (character c) (optimize (speed 3) (safety 0)))
+ (or (char= c #\Space) (char= c #\Tab) (char= c #\Return)
+ (char= c #\Linefeed)
+ #+allegro (char= c #\%space)
+ #+lispworks (char= c #\No-Break-Space)))
-(defun string-ws? (str)
+(defun is-string-whitespace (str)
"Return t if string is all whitespace"
- (when (stringp str)
- (null (find-if #'not-whitespace? str))))
+ (every #'is-char-whitespace str))
+
+(defun string-right-trim-whitespace (str)
+ (string-right-trim *whitespace-chars* str))
+
+(defun string-left-trim-whitespace (str)
+ (string-left-trim *whitespace-chars* str))
+
+(defun string-trim-whitespace (str)
+ (string-trim *whitespace-chars* str))
-#+ignore
-(defun string-replace-chars-strings (str repl-alist)
+(defun replaced-string-length (str repl-alist)
+ (declare (simple-string str)
+ (optimize (speed 3) (safety 0) (space 0)))
+ (do* ((i 0 (1+ i))
+ (orig-len (length str))
+ (new-len orig-len))
+ ((= i orig-len) new-len)
+ (declare (fixnum i orig-len new-len))
+ (let* ((c (char str i))
+ (match (assoc c repl-alist :test #'char=)))
+ (declare (character c))
+ (when match
+ (incf new-len (1- (length
+ (the simple-string (cdr match)))))))))
+
+(defun substitute-chars-strings (str repl-alist)
"Replace all instances of a chars with a string. repl-alist is an assoc
list of characters and replacement strings."
- (let* ((orig-len (length str))
- (new-len orign-len))
- (declare (fixnum orig-len new-len))
- (dotimes (i orign-len)
- (declare (fixnum i))
- (let ((c (schar i str)))
- )))
- str)
+ (declare (simple-string str)
+ (optimize (speed 3) (safety 0) (space 0)))
+ (do* ((orig-len (length str))
+ (new-string (make-string (replaced-string-length str repl-alist)))
+ (spos 0 (1+ spos))
+ (dpos 0))
+ ((>= spos orig-len)
+ new-string)
+ (declare (fixnum spos dpos) (simple-string new-string))
+ (let* ((c (char str spos))
+ (match (assoc c repl-alist :test #'char=)))
+ (declare (character c))
+ (if match
+ (let* ((subst (cdr match))
+ (len (length subst)))
+ (declare (fixnum len)
+ (simple-string subst))
+ (dotimes (j len)
+ (declare (fixnum j))
+ (setf (char new-string dpos) (char subst j))
+ (incf dpos)))
+ (progn
+ (setf (char new-string dpos) c)
+ (incf dpos))))))
(defun escape-xml-string (string)
"Escape invalid XML characters"
- (string-replace-char-string
- (string-replace-char-string string #\& "&")
- #\< "<"))
-
-(defun string-replace-char-string (string repl-char repl-str)
- "Replace all occurances of repl-char with repl-str"
- (declare (simple-string string))
- (let ((count (count repl-char string)))
- (declare (fixnum count))
- (if (zerop count)
- string
- (locally (declare (optimize (speed 3) (safety 0)))
- (let* ((old-length (length string))
- (repl-length (length repl-str))
- (new-string (make-string (the fixnum
- (+ old-length
- (the fixnum
- (* count
- (the fixnum (1- repl-length)))))))))
- (declare (fixnum old-length repl-length)
- (simple-string new-string))
- (let ((newpos 0))
- (declare (fixnum newpos))
- (dotimes (oldpos (length string))
- (declare (fixnum oldpos))
- (if (char= repl-char (schar string oldpos))
- (dotimes (repl-pos repl-length)
- (declare (fixnumm repl-pos))
- (setf (schar new-string newpos) (schar repl-str repl-pos))
- (incf newpos))
- (progn
- (setf (schar new-string newpos) (schar string oldpos))
- (incf newpos)))))
- new-string)))))
-
-
+ (substitute-chars-strings string '((#\& . "&") (#\< . "<"))))
+
+(defun make-usb8-array (len)
+ (make-array len :element-type '(unsigned-byte 8)))
+
+(defun usb8-array-to-string (vec &key (start 0) end)
+ (declare (type (simple-array (unsigned-byte 8) (*)) vec)
+ (fixnum start))
+ (unless end
+ (setq end (length vec)))
+ (let* ((len (- end start))
+ (str (make-string len)))
+ (declare (fixnum len)
+ (simple-string str)
+ (optimize (speed 3) (safety 0)))
+ (do ((i 0 (1+ i)))
+ ((= i len) str)
+ (declare (fixnum i))
+ (setf (schar str i) (code-char (aref vec (the fixnum (+ i start))))))))
+
+(defun string-to-usb8-array (str)
+ (declare (simple-string str))
+ (let* ((len (length str))
+ (vec (make-usb8-array len)))
+ (declare (fixnum len)
+ (type (simple-array (unsigned-byte 8) (*)) vec)
+ (optimize (speed 3)))
+ (do ((i 0 (1+ i)))
+ ((= i len) vec)
+ (declare (fixnum i))
+ (setf (aref vec i) (char-code (schar str i))))))
+
+(defun concat-separated-strings (separator &rest lists)
+ (format nil (concatenate 'string "~{~A~^" (string separator) "~}")
+ (append-sublists lists)))
+
+(defun only-null-list-elements-p (lst)
+ (or (null lst) (every #'null lst)))
+
+(defun print-separated-strings (strm separator &rest lists)
+ (declare (optimize (speed 3) (safety 0) (space 0) (debug 0)
+ (compilation-speed 0)))
+ (do* ((rest-lists lists (cdr rest-lists))
+ (list (car rest-lists) (car rest-lists))
+ (last-list (only-null-list-elements-p (cdr rest-lists))
+ (only-null-list-elements-p (cdr rest-lists))))
+ ((null rest-lists) strm)
+ (do* ((lst list (cdr lst))
+ (elem (car lst) (car lst))
+ (last-elem (null (cdr lst)) (null (cdr lst))))
+ ((null lst))
+ (write-string elem strm)
+ (unless (and last-elem last-list)
+ (write-string separator strm)))))
+
+(eval-when (:compile-toplevel :load-toplevel :execute)
+ (defmacro def-prefixed-number-string (fn-name type &optional doc)
+ `(defun ,fn-name (num pchar len)
+ ,@(when (stringp doc) (list doc))
+ (declare (optimize (speed 3) (safety 0) (space 0))
+ (fixnum len)
+ (,type num))
+ (when pchar
+ (incf len))
+ (do* ((zero-code (char-code #\0))
+ (result (make-string len :initial-element #\0))
+ (minus? (minusp num))
+ (val (if minus? (- num) num)
+ (nth-value 0 (floor val 10)))
+ (pos (1- len) (1- pos))
+ (mod (mod val 10) (mod val 10)))
+ ((or (zerop val) (minusp pos))
+ (when pchar
+ (setf (schar result 0) pchar))
+ (when minus? (setf (schar result (if pchar 1 0)) #\-))
+ result)
+ (declare (,type val)
+ (fixnum mod zero-code pos)
+ (boolean minus?)
+ (simple-string result))
+ (setf (schar result pos) (code-char (the fixnum (+ zero-code mod))))))))
+
+(def-prefixed-number-string prefixed-fixnum-string fixnum
+ "Outputs a string of LEN digit with an optional initial character PCHAR.
+Leading zeros are present. LEN must be a fixnum.")
+
+(def-prefixed-number-string prefixed-integer-string integer
+ "Outputs a string of LEN digit with an optional initial character PCHAR.
+Leading zeros are present. LEN must be an integer.")
+
+(defun integer-string (num len)
+ "Outputs a string of LEN digit with an optional initial character PCHAR.
+Leading zeros are present."
+ (declare (optimize (speed 3) (safety 0) (space 0))
+ (type fixnum len)
+ (type integer num))
+ (do* ((zero-code (char-code #\0))
+ (result (make-string len :initial-element #\0))
+ (minus? (minusp num))
+ (val (if minus? (- 0 num) num)
+ (nth-value 0 (floor val 10)))
+ (pos (1- len) (1- pos))
+ (mod (mod val 10) (mod val 10)))
+ ((or (zerop val) (minusp pos))
+ (when minus? (setf (schar result 0) #\-))
+ result)
+ (declare (fixnum mod zero-code pos) (simple-string result) (integer val))
+ (setf (schar result pos) (code-char (+ zero-code mod)))))
+
+(defun fast-string-search (substr str substr-length startpos endpos)
+ "Optimized search for a substring in a simple-string"
+ (declare (simple-string substr str)
+ (fixnum substr-length startpos endpos)
+ (optimize (speed 3) (space 0) (safety 0)))
+ (do* ((pos startpos (1+ pos))
+ (lastpos (- endpos substr-length)))
+ ((> pos lastpos) nil)
+ (declare (fixnum pos lastpos))
+ (do ((i 0 (1+ i)))
+ ((= i substr-length)
+ (return-from fast-string-search pos))
+ (declare (fixnum i))
+ (unless (char= (schar str (+ i pos)) (schar substr i))
+ (return nil)))))
+
+(defun string-delimited-string-to-list (str substr)
+ "splits a string delimited by substr into a list of strings"
+ (declare (simple-string str substr)
+ (optimize (speed 3) (safety 0) (space 0) (compilation-speed 0)
+ (debug 0)))
+ (do* ((substr-len (length substr))
+ (strlen (length str))
+ (output '())
+ (pos 0)
+ (end (fast-string-search substr str substr-len pos strlen)
+ (fast-string-search substr str substr-len pos strlen)))
+ ((null end)
+ (when (< pos strlen)
+ (push (subseq str pos) output))
+ (nreverse output))
+ (declare (fixnum strlen substr-len pos)
+ (type (or fixnum null) end))
+ (push (subseq str pos end) output)
+ (setq pos (+ end substr-len))))
+
+(defun string-to-list-skip-delimiter (str &optional (delim #\space))
+ "Return a list of strings, delimited by spaces, skipping spaces."
+ (declare (simple-string str)
+ (optimize (speed 0) (space 0) (safety 0)))
+ (do* ((results '())
+ (end (length str))
+ (i (position-not-char delim str 0 end)
+ (position-not-char delim str j end))
+ (j (when i (position-char delim str i end))
+ (when i (position-char delim str i end))))
+ ((or (null i) (null j))
+ (when (and i (< i end))
+ (push (subseq str i end) results))
+ (nreverse results))
+ (declare (fixnum end)
+ (type (or fixnum null) i j))
+ (push (subseq str i j) results)))
+
+(defun string-starts-with (start str)
+ (and (>= (length str) (length start))
+ (string-equal start str :end2 (length start))))
+
+(defun count-string-char (s c)
+ "Return a count of the number of times a character appears in a string"
+ (declare (simple-string s)
+ (character c)
+ (optimize (speed 3) (safety 0)))
+ (do ((len (length s))
+ (i 0 (1+ i))
+ (count 0))
+ ((= i len) count)
+ (declare (fixnum i len count))
+ (when (char= (schar s i) c)
+ (incf count))))
+
+(defun count-string-char-if (pred s)
+ "Return a count of the number of times a predicate is true
+for characters in a string"
+ (declare (simple-string s)
+ (type (or function symbol) pred)
+ (optimize (speed 3) (safety 0) (space 0)))
+ (do ((len (length s))
+ (i 0 (1+ i))
+ (count 0))
+ ((= i len) count)
+ (declare (fixnum i len count))
+ (when (funcall pred (schar s i))
+ (incf count))))
+
+
+;;; URL Encoding
+
+(defun non-alphanumericp (ch)
+ (not (alphanumericp ch)))
+
+(defvar +hex-chars+ "0123456789ABCDEF")
+(declaim (type simple-string +hex-chars+))
+
+(defun hexchar (n)
+ (declare (type (integer 0 15) n))
+ (schar +hex-chars+ n))
+
+(defconstant* +char-code-lower-a+ (char-code #\a))
+(defconstant* +char-code-upper-a+ (char-code #\A))
+(defconstant* +char-code-0+ (char-code #\0))
+(declaim (type fixnum +char-code-0+ +char-code-upper-a+
+ +char-code-0))
+
+(defun charhex (ch)
+ "convert hex character to decimal"
+ (let ((code (char-code (char-upcase ch))))
+ (declare (fixnum ch))
+ (if (>= code +char-code-upper-a+)
+ (+ 10 (- code +char-code-upper-a+))
+ (- code +char-code-0+))))
+
+(defun binary-sequence-to-hex-string (seq)
+ (let ((list (etypecase seq
+ (list seq)
+ (sequence (map 'list #'identity seq)))))
+ (string-downcase (format nil "~{~2,'0X~}" list))))
+
+(defun encode-uri-string (query)
+ "Escape non-alphanumeric characters for URI fields"
+ (declare (simple-string query)
+ (optimize (speed 3) (safety 0) (space 0)))
+ (do* ((count (count-string-char-if #'non-alphanumericp query))
+ (len (length query))
+ (new-len (+ len (* 2 count)))
+ (str (make-string new-len))
+ (spos 0 (1+ spos))
+ (dpos 0 (1+ dpos)))
+ ((= spos len) str)
+ (declare (fixnum count len new-len spos dpos)
+ (simple-string str))
+ (let ((ch (schar query spos)))
+ (if (non-alphanumericp ch)
+ (let ((c (char-code ch)))
+ (setf (schar str dpos) #\%)
+ (incf dpos)
+ (setf (schar str dpos) (hexchar (logand (ash c -4) 15)))
+ (incf dpos)
+ (setf (schar str dpos) (hexchar (logand c 15))))
+ (setf (schar str dpos) ch)))))
+
+(defun decode-uri-string (query)
+ "Unescape non-alphanumeric characters for URI fields"
+ (declare (simple-string query)
+ (optimize (speed 3) (safety 0) (space 0)))
+ (do* ((count (count-string-char query #\%))
+ (len (length query))
+ (new-len (- len (* 2 count)))
+ (str (make-string new-len))
+ (spos 0 (1+ spos))
+ (dpos 0 (1+ dpos)))
+ ((= spos len) str)
+ (declare (fixnum count len new-len spos dpos)
+ (simple-string str))
+ (let ((ch (schar query spos)))
+ (if (char= #\% ch)
+ (let ((c1 (charhex (schar query (1+ spos))))
+ (c2 (charhex (schar query (+ spos 2)))))
+ (declare (fixnum c1 c2))
+ (setf (schar str dpos)
+ (code-char (logior c2 (ash c1 4))))
+ (incf spos 2))
+ (setf (schar str dpos) ch)))))
+
+
+(defun uri-query-to-alist (query)
+ "Converts non-decoded URI query to an alist of settings"
+ (mapcar (lambda (set)
+ (let ((lst (kmrcl:delimited-string-to-list set #\=)))
+ (cons (first lst) (second lst))))
+ (kmrcl:delimited-string-to-list
+ (kmrcl:decode-uri-string query) #\&)))
+
+(eval-when (:compile-toplevel :load-toplevel :execute)
+ (defvar +unambiguous-charset+
+ "abcdefghjkmnpqrstuvwxyz123456789ABCDEFGHJKLMNPQSRTUVWXYZ")
+ (defconstant* +unambiguous-length+ (length +unambiguous-charset+)))
+
+(defun random-char (&optional (set :lower-alpha))
+ (ecase set
+ (:lower-alpha
+ (code-char (+ +char-code-lower-a+ (random 26))))
+ (:lower-alphanumeric
+ (let ((n (random 36)))
+ (if (>= n 26)
+ (code-char (+ +char-code-0+ (- n 26)))
+ (code-char (+ +char-code-lower-a+ n)))))
+ (:upper-alpha
+ (code-char (+ +char-code-upper-a+ (random 26))))
+ (:unambiguous
+ (schar +unambiguous-charset+ (random +unambiguous-length+)))
+ (:upper-lower-alpha
+ (let ((n (random 52)))
+ (if (>= n 26)
+ (code-char (+ +char-code-upper-a+ (- n 26)))
+ (code-char (+ +char-code-lower-a+ n)))))))
+
+
+(defun random-string (&key (length 10) (set :lower-alpha))
+ "Returns a random lower-case string."
+ (declare (optimize (speed 3)))
+ (let ((s (make-string length)))
+ (declare (simple-string s))
+ (dotimes (i length s)
+ (setf (schar s i) (random-char set)))))
+
+
+(defun first-char (s)
+ (declare (simple-string s))
+ (when (and (stringp s) (plusp (length s)))
+ (schar s 0)))
+
+(defun last-char (s)
+ (declare (simple-string s))
+ (when (stringp s)
+ (let ((len (length s)))
+ (when (plusp len))
+ (schar s (1- len)))))
+
+(defun ensure-string (v)
+ (typecase v
+ (string v)
+ (character (string v))
+ (symbol (symbol-name v))
+ (otherwise (write-to-string v))))
+
+(defun string-right-trim-one-char (char str)
+ (declare (simple-string str))
+ (let* ((len (length str))
+ (last (1- len)))
+ (declare (fixnum len last))
+ (if (char= char (schar str last))
+ (subseq str 0 last)
+ str)))
+
+
+(defun string-strip-ending (str endings)
+ (if (stringp endings)
+ (setq endings (list endings)))
+ (let ((len (length str)))
+ (dolist (ending endings str)
+ (when (and (>= len (length ending))
+ (string-equal ending
+ (subseq str (- len
+ (length ending)))))
+ (return-from string-strip-ending
+ (subseq str 0 (- len (length ending))))))))
+
+
+(defun string-maybe-shorten (str maxlen)
+ (string-elide str maxlen :end))
+
+(defun string-elide (str maxlen position)
+ (declare (fixnum maxlen))
+ (let ((len (length str)))
+ (declare (fixnum len))
+ (cond
+ ((<= len maxlen)
+ str)
+ ((<= maxlen 3)
+ "...")
+ ((eq position :middle)
+ (multiple-value-bind (mid remain) (truncate maxlen 2)
+ (let ((end1 (- mid 1))
+ (start2 (- len (- mid 2) remain)))
+ (concatenate 'string (subseq str 0 end1) "..." (subseq str start2)))))
+ ((or (eq position :end) t)
+ (concatenate 'string (subseq str 0 (- maxlen 3)) "...")))))
+
+(defun shrink-vector (str size)
+ #+allegro
+ (excl::.primcall 'sys::shrink-svector str size)
+ #+cmu
+ (lisp::shrink-vector str size)
+ #+lispworks
+ (system::shrink-vector$vector str size)
+ #+sbcl
+ (sb-kernel:shrink-vector str size)
+ #+scl
+ (common-lisp::shrink-vector str size)
+ #-(or allegro cmu lispworks sbcl scl)
+ (setq str (subseq str 0 size))
+ str)
+
+(defun lex-string (string &key (whitespace '(#\space #\newline)))
+ "Separates a string at whitespace and returns a list of strings"
+ (flet ((is-sep (char) (member char whitespace :test #'char=)))
+ (let ((tokens nil))
+ (do* ((token-start
+ (position-if-not #'is-sep string)
+ (when token-end
+ (position-if-not #'is-sep string :start (1+ token-end))))
+ (token-end
+ (when token-start
+ (position-if #'is-sep string :start token-start))
+ (when token-start
+ (position-if #'is-sep string :start token-start))))
+ ((null token-start) (nreverse tokens))
+ (push (subseq string token-start token-end) tokens)))))
+
+(defun split-alphanumeric-string (string)
+ "Separates a string at any non-alphanumeric chararacter"
+ (declare (simple-string string)
+ (optimize (speed 3) (safety 0)))
+ (flet ((is-sep (char)
+ (declare (character char))
+ (and (non-alphanumericp char)
+ (not (char= #\_ char)))))
+ (let ((tokens nil))
+ (do* ((token-start
+ (position-if-not #'is-sep string)
+ (when token-end
+ (position-if-not #'is-sep string :start (1+ token-end))))
+ (token-end
+ (when token-start
+ (position-if #'is-sep string :start token-start))
+ (when token-start
+ (position-if #'is-sep string :start token-start))))
+ ((null token-start) (nreverse tokens))
+ (push (subseq string token-start token-end) tokens)))))
+
+
+(defun trim-non-alphanumeric (word)
+ "Strip non-alphanumeric characters from beginning and end of a word."
+ (declare (simple-string word)
+ (optimize (speed 3) (safety 0) (space 0)))
+ (let* ((start 0)
+ (len (length word))
+ (end len))
+ (declare (fixnum start end len))
+ (do ((done nil))
+ ((or done (= start end)))
+ (if (alphanumericp (schar word start))
+ (setq done t)
+ (incf start)))
+ (when (> end start)
+ (do ((done nil))
+ ((or done (= start end)))
+ (if (alphanumericp (schar word (1- end)))
+ (setq done t)
+ (decf end))))
+ (if (or (plusp start) (/= len end))
+ (subseq word start end)
+ word)))
+
+
+(defun collapse-whitespace (s)
+ "Convert multiple whitespace characters to a single space character."
+ (declare (simple-string s)
+ (optimize (speed 3) (safety 0)))
+ (with-output-to-string (stream)
+ (do ((pos 0 (1+ pos))
+ (in-white nil)
+ (len (length s)))
+ ((= pos len))
+ (declare (fixnum pos len))
+ (let ((c (schar s pos)))
+ (declare (character c))
+ (cond
+ ((kl:is-char-whitespace c)
+ (unless in-white
+ (write-char #\space stream))
+ (setq in-white t))
+ (t
+ (setq in-white nil)
+ (write-char c stream)))))))
+
+(defun string->list (string)
+ (let ((eof (list nil)))
+ (with-input-from-string (stream string)
+ (do ((x (read stream nil eof) (read stream nil eof))
+ (l nil (cons x l)))
+ ((eq x eof) (nreverse l))))))