X-Git-Url: https://git.distorted.org.uk/~mdw/sod/blobdiff_plain/26c5ecfef79e0158c3ea38e9c32ad1fe3e85be3e..40d95de71fca4c3b7b145d5ba73d1420e8854673:/src/lexer-impl.lisp

diff --git a/src/lexer-impl.lisp b/src/lexer-impl.lisp
index 821849b..42370c0 100644
--- a/src/lexer-impl.lisp
+++ b/src/lexer-impl.lisp
@@ -39,15 +39,12 @@
 ;;;--------------------------------------------------------------------------
 ;;; Indicators and error messages.
 
-(defun show-char (stream char &optional colonp atsignp)
-  "Format CHAR to STREAM in a readable way.
-
-   Usable in `format''s ~/.../ command."
-  (declare (ignore colonp atsignp))
-  (cond ((null char) (write-string "<end-of-file>" stream))
+(defun show-char (char)
+  "Format CHAR as a string in a readable way."
+  (cond ((null char) "<end-of-file>")
 	((and (graphic-char-p char) (char/= char #\space))
-	 (format stream "`~C'" char))
-	(t (format stream "<~(~:C~)>" char))))
+	 (format nil "`~C'" char))
+	(t (format nil "<~(~:C~)>" char))))
 
 (defun skip-until (scanner token-types &key keep-end)
   "This is the implementation of the `skip-until' parser."
@@ -59,7 +56,8 @@
       (return (values token-types nil consumedp)))
     (scanner-step scanner)))
 
-(defun parse-error-recover (scanner parser recover &key ignore-unconsumed)
+(defun parse-error-recover (scanner parser recover
+			    &key ignore-unconsumed force-progress)
   "This is the implementation of the `error' parser."
   (multiple-value-bind (result win consumedp) (funcall parser)
     (cond ((or win
@@ -84,8 +82,8 @@
 	   ;; current token.  Finally, if we are at EOF then our best bet is
 	   ;; simply to propagate the current failure back to the caller, but
 	   ;; we handled that case above.
-	   (syntax-error scanner result :continuep t)
-	   (unless consumedp (scanner-step scanner))
+	   (syntax-error scanner result)
+	   (when (and force-progress (not consumedp)) (scanner-step scanner))
 	   (funcall recover)))))
 
 ;;;--------------------------------------------------------------------------
@@ -100,7 +98,18 @@
 	       (parse (many (acc init (+ (* acc radix) it) :min min)
 			(label (list :digit radix)
 			       (filter (lambda (ch)
-					 (digit-char-p ch radix))))))))
+					 (digit-char-p ch radix)))))))
+	     (start-floc ()
+	       ;; This is a little nasty.  We scan the first token during
+	       ;; instance initialization, as a result of `shared-initialize'
+	       ;; on `token-scanner'.  Unfortunately, this happens before
+	       ;; we've had a chance to initialize our own `filename' slot.
+	       ;; This means that we can't use the SCANNER as a file
+	       ;; location, however tempting it might be.  So we have this
+	       ;; hack.
+	       (make-file-location (scanner-filename char-scanner)
+				   (scanner-line scanner)
+				   (scanner-column scanner))))
 
 	;; Skip initial junk, and remember the place.
 	(loop
@@ -127,13 +136,25 @@
 				      (progn (write-char it out) out)
 				      :final (get-output-stream-string out))
 			     (or (and #\\ :any) (not quote))))
-		 (nil (char quote)))
+		 (nil (or (char quote)
+			  (seq (:eof)
+			    (lexer-error char-scanner (list quote))
+			    (info-with-location
+			     (start-floc) "Literal started here")))))
 	     (ecase quote
 	       (#\" contents)
 	       (#\' (case (length contents)
 		      (1 (char contents 0))
-		      (0 (cerror* "Empty character literal") #\?)
-		      (t (cerror* "Too many characters in literal")
+		      (0 (cerror*-with-location (start-floc)
+						'simple-lexer-error
+						:format-control
+						"Empty character literal")
+			 #\?)
+		      (t (cerror*-with-location (start-floc)
+						'simple-lexer-error
+						:format-control
+						"Too many characters ~
+						 in character literal")
 			 (char contents 0))))))
 	   (values (etypecase it
 		     (character :char)