*** empty log message ***

original commit: 9d9b93bd8026bff1c523a7257a4d4eafefb15752

collects/parser-tools/private-yacc/input-file-parser.ss

@@ -105,7 +105,7 @@
 	  (set! counter (add1 counter))))
        term-list)))
   
-  ;; Retrieves the terminal symbols from a terminals-def (See terminal-syntax.xx)
+  ;; Retrieves the terminal symbols from a terminals-def (See terminal-syntax.ss)
   ;; get-terms-from-def: syntax-object -> symbol list
   (define (get-terms-from-def term-syn)
     (let ((t (syntax-local-value term-syn (lambda () #f))))
@@ -360,7 +360,14 @@
                     'parser-productions
                     "A production for a non-terminal must be (non-term right-hand-side ...) with at least 1 right hand side"
                     prods-so))))))
-	
+		 
+        (if (not (memq start-sym list-of-non-terms))
+            (raise-syntax-error
+             'parser-start
+             (format "Start symbol ~a not defined as a non-terminal"
+                     start-sym)
+             start))
+                 
         (set! counter 1)
         (let* ((start (make-non-term (gensym) 0))
                (end-non-term (make-non-term (gensym) 1))
@@ -384,14 +391,7 @@
                (nulls (nullable (apply append prods) 
                                 (+ 2 (length non-terms)))))
           
-          
+
-	  (if (not (memq start-sym list-of-non-terms))
-	      (raise-syntax-error
-	       'parser-start
-	       (format "Start symbol ~a not defined as a non-terminal"
-		       start-sym)
-	       start))
-                 
 ;;           (printf "nullable: {~a}~n~n"
 ;;                   (apply string-append
 ;;                          (let loop ((i 0))

collects/parser-tools/private-yacc/lr0.ss

@@ -76,7 +76,7 @@
 	     ;; given a non-terminal symbol C, return those non-terminal 
 	     ;; symbols A s.t. C -> An for some string of terminals and
 	     ;; non-terminals n where -> means a rightmost derivation in many 
-	     ;; steps.  Assumes that each non-term can be reduces to a string 
+	     ;; steps.  Assumes that each non-term can be reduced to a string 
 	     ;; of terms.
 	     (first-non-term 
 	      (digraph (grammar-non-terms grammar)

collects/parser-tools/private-yacc/parser-builder.ss

@@ -137,13 +137,13 @@
                                                  ,(if (token? ip) (token-value ip) #f)
                                                  ,@stack)))
 					(else
-					 (printf "discard input:~a~n" tok)
+					 ;; (printf "discard input:~a~n" tok)
 					 (set! ip (get-token))
                                          (set! tok (input->token ip))
 					 (remove-input))))))
 				  (remove-states
 				   (lambda ()
-				     (let ((a (find-action stack 'error #f)))
+				     (let ((a (find-action stack (make-token 'error #f) #f)))
 				       (cond
 					((shift? a)
 					 ;; (printf "shift:~a~n" (shift-state a))