+ (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))
+
+(defun escape-uri-field (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)))))