Implement faster key/value parser.

src/util-parser.scm

@@ -35,7 +35,6 @@
  
  (import scheme
 	 (chicken base)
-	 (chicken irregex)
 	 testing)
 
  ;; Pass 0: Removes any comments and removes any leading and trailing
@@ -69,17 +68,29 @@
  ;; one token was there and pair of symbol and string if both key and
  ;; the value were present.
  (define (parser-parse-line line)
-   (if (= (string-length line) 0)
-       #f
-       (let ((dm (irregex-search (irregex "[ \\t]" 'u) line)))
-	 (if dm
-	     (let* ((sep-idx (irregex-match-start-index dm))
-		    (key-str (substring line 0 sep-idx))
-		    (key (string->symbol key-str))
-		    (sep+val (substring line sep-idx))
-		    (val (irregex-replace (irregex "^[ \\t]*" 'u) sep+val "")))
-	       (cons key val))
-	     (string->symbol line)))))
+   (let* ((llen (string-length line))
+	  (spos (let sloop ((sidx 0))
+		  (if (or (= sidx llen)
+			  (let ((ch (string-ref line sidx)))
+			    (or (eq? ch #\space)
+				(eq? ch #\tab))))
+		      sidx
+		      (sloop (add1 sidx)))))
+	  (vpos (let vloop ((vidx spos))
+		  (if (or (= vidx llen)
+			  (not (let ((ch (string-ref line vidx)))
+				 (or (eq? ch #\space)
+				     (eq? ch #\tab)))))
+		      vidx
+		      (vloop (add1 vidx))))))
+     (if (= llen 0)
+	 #f
+	 (if (< vpos llen)
+	     (cons (string->symbol
+		    (substring line 0 spos))
+		   (substring line vpos))
+	     (string->symbol
+	      (substring line 0 spos))))))
 
  ;; Self-tests
  (define (parser-tests!)