Synthesize the first imaginary token to take location from the stream.

Rather than assume the token stream starts at line 1, column 0, position 1, use the stream to inform the position.
dyoo · Jan 9, 2013 · 1b37e25 · 1b37e25
1 parent e92e51b
commit 1b37e25
Showing 1 changed file with 15 additions and 7 deletions.
diff --git a/collects/algol60/cfg-parser.rkt b/collects/algol60/cfg-parser.rkt
@@ -27,6 +27,8 @@
 ;; grammar to tokens specific to this parser. In other words, this
 ;; parser uses `parser' so that it doesn't have to know anything about
 ;; tokens.
+;;
+
 
 
 (require parser-tools/yacc
@@ -758,13 +760,19 @@
                      (#,start tok-list
                               ;; we simulate a token at the very beginning with zero width
                               ;; for use with the position-generating code (*-start-pos, *-end-pos).
-                              (tok #f #f #f
-                                   (position 1
-                                             #,(if src-pos? #'1 #'#f) 
-                                             #,(if src-pos? #'0 #'#f))
-                                   (position 1 
-                                             #,(if src-pos? #'1 #'#f)
-                                             #,(if src-pos? #'0 #'#f))) 
+                              (if (null? tok-list)
+                                  (tok #f #f #f
+                                       (position 1
+                                                 #,(if src-pos? #'1 #'#f) 
+                                                 #,(if src-pos? #'0 #'#f))
+                                       (position 1 
+                                                 #,(if src-pos? #'1 #'#f)
+                                                 #,(if src-pos? #'0 #'#f)))
+                                  (tok (tok-name (car tok-list))
+                                       (tok-orig-name (car tok-list))
+                                       (tok-val (car tok-list))
+                                       (tok-start (car tok-list))
+                                       (tok-start (car tok-list))))
                               0 
                               (length tok-list)
                               success-k