*** empty log message ***

original commit: 0913b67e5f88cfd754cbf7abeb09b0d854fe413f

collects/parser-tools/lex.ss

@@ -20,8 +20,16 @@
                         (let ((match
                                (push-back lb (- length longest-match-length))))
                           (if (not longest-match-action)
-			      (error 'lexer (format "No match found in input starting with: ~a" 
+                              (raise (make-exn:read 
-                                                    (list->string (lex-buffer-from lb)))))
+                                      (format "lexer: No match found in input starting with: ~a"
+                                              (list->string (lex-buffer-from lb)))
+                                      (current-continuation-marks)
+                                      (lex-buffer-ip lb)
+                                      #f
+                                      (position-line first-pos)
+                                      (position-col first-pos)
+                                      (position-offset first-pos)
+                                      (- (position-offset end-pos) (position-offset first-pos)))))
                           (longest-match-action
                            (lambda ()
                              first-pos)
@@ -142,7 +150,7 @@
   ;; c = char | eof
   ;; lex-buf = 
   ;;   (make-lex-buffer input-port (c list) (c list) int int int (int list))
-  (define-struct lex-buffer (ip from to offset line col line-lengths))
+  (define-struct lex-buffer (ip from to offset line col line-lengths tab-skips))
 
   ;; make-lex-buf: input-port -> lex-buf
   (define make-lex-buf
@@ -152,7 +160,7 @@
        ((not (input-port? ip))
 	(raise-type-error 'make-lex-buf "input-port" 0 ip))
        (else
-	(make-lex-buffer ip null null 1 1 1 null))))
+	(make-lex-buffer ip null null 1 1 1 null null))))
      ((ip offsets)
       (cond
        ((not (input-port? ip))
@@ -163,7 +171,7 @@
 	    (not (andmap (lambda (x) (>= x 0)) offsets)))
 	(raise-type-error 'make-lex-buf "list of 3 non-negative exact integers" 1 ip offsets))
        (else
-	(make-lex-buffer ip null null (add1 (caddr offsets)) (add1 (car offsets)) (add1 (cadr offsets)) null))))))
+	(make-lex-buffer ip null null (add1 (caddr offsets)) (add1 (car offsets)) (add1 (cadr offsets)) null null))))))
 
   ;; next-char: lex-buf -> c
   ;; gets the next character from the buffer
@@ -190,7 +198,8 @@
 	(set-lex-buffer-to! lb (cons char-in (lex-buffer-to lb)))
 	(cond 
 	 ((eq? #\tab char-in)
-	  (let ((skip-amt 1));(- 8 (modulo (lex-buffer-col lb) 8))))
+	  (let ((skip-amt (- 8 (modulo (lex-buffer-col lb) 8))))
+            (set-lex-buffer-tab-skips! lb (cons skip-amt (lex-buffer-tab-skips lb)))
 	    (set-lex-buffer-col! lb (+ skip-amt (lex-buffer-col lb)))
 	    (set-lex-buffer-offset! lb (+ skip-amt (lex-buffer-col lb)))))
 	 ((eq? #\newline char-in)
@@ -225,19 +234,17 @@
 		 (else
 		  (cond
 		   ((eq? #\newline (car from))
-		    (set-lex-buffer-line! 
+		    (set-lex-buffer-line! lb (sub1 (lex-buffer-line lb)))
-		     lb
+		    (set-lex-buffer-col! lb (car (lex-buffer-line-lengths lb)))
-		     (sub1 (lex-buffer-line lb)))
+		    (set-lex-buffer-line-lengths! lb (cdr (lex-buffer-line-lengths lb))))
-		    (set-lex-buffer-col!
+                   ((eq? #\tab (car from))
-		     lb
+                    (set-lex-buffer-col! lb (- (lex-buffer-col lb) 
-		     (car (lex-buffer-line-lengths lb)))
+                                               (car (lex-buffer-tab-skips lb))))
-		    (set-lex-buffer-line-lengths!
+                    (set-lex-buffer-offset! lb (- (add1 (lex-buffer-offset lb))
-		     lb
+                                                  (car (lex-buffer-tab-skips lb))))
-		     (cdr (lex-buffer-line-lengths lb))))
+                    (set-lex-buffer-tab-skips! lb (cdr (lex-buffer-tab-skips lb))))
                    (else
-		    (set-lex-buffer-col! 
+                    (set-lex-buffer-col! lb (sub1 (lex-buffer-col lb)))))
-		     lb 
-		     (sub1 (lex-buffer-col lb)))))
                   (switch-buffers (cdr from) 
                                   (cons (car from) to) 
                                   (sub1 num-to-add)))))))
@@ -249,6 +256,7 @@
         (set-lex-buffer-to! lb null)
         (set-lex-buffer-offset! lb (- (lex-buffer-offset lb) i))
         (set-lex-buffer-line-lengths! lb null)
+        (set-lex-buffer-tab-skips! lb null)
         ret)))
 
   (define-struct position (offset line col))