X-Git-Url: https://git.distorted.org.uk/~mdw/sod/blobdiff_plain/e046c3f65a8f7241889fb9b6005aac21e2aad1a8..refs/heads/mdw/progfmt:/src/lexer-impl.lisp

diff --git a/src/lexer-impl.lisp b/src/lexer-impl.lisp
index 48109b1..ccaca5c 100644
--- a/src/lexer-impl.lisp
+++ b/src/lexer-impl.lisp
@@ -39,20 +39,27 @@
 ;;;--------------------------------------------------------------------------
 ;;; 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)
+(defun %skip-until (scanner token-types
+		    &key (keep-end (not (null (cdr token-types)))))
   "This is the implementation of the `skip-until' parser."
   (do ((consumedp nil t))
-      ((member (token-type scanner) token-types)
+      ((let ((type (token-type scanner))
+	     (value (token-value scanner)))
+	 (some (lambda (spec)
+		 (multiple-value-bind (want-type want-value)
+		     (cond ((listp spec) (values (car spec) (cadr spec)))
+			   (t (values spec t)))
+		   (and (eq want-type type)
+			(or (eq want-value t)
+			    (equal want-value value)))))
+	       token-types))
        (unless keep-end (scanner-step scanner))
        (values nil t (or keep-end consumedp)))
     (when (scanner-at-eof-p scanner)
@@ -60,7 +67,7 @@
     (scanner-step scanner)))
 
 (defun parse-error-recover (scanner parser recover
-			    &key ignore-unconsumed force-progress)
+			    &key ignore-unconsumed force-progress action)
   "This is the implementation of the `error' parser."
   (multiple-value-bind (result win consumedp) (funcall parser)
     (cond ((or win
@@ -86,6 +93,7 @@
 	   ;; simply to propagate the current failure back to the caller, but
 	   ;; we handled that case above.
 	   (syntax-error scanner result)
+	   (when action (funcall action))
 	   (when (and force-progress (not consumedp)) (scanner-step scanner))
 	   (funcall recover)))))
 
@@ -149,13 +157,15 @@
 	       (#\' (case (length contents)
 		      (1 (char contents 0))
 		      (0 (cerror*-with-location (start-floc)
-						"Lexical error: ~
-						 empty character literal")
+						'simple-lexer-error
+						:format-control
+						"Empty character literal")
 			 #\?)
 		      (t (cerror*-with-location (start-floc)
-						"Lexical error: ~
-						 too many characters ~
-						 in literal")
+						'simple-lexer-error
+						:format-control
+						"Too many characters ~
+						 in character literal")
 			 (char contents 0))))))
 	   (values (etypecase it
 		     (character :char)
@@ -178,6 +188,14 @@
 
 	  ;; Some special punctuation sequences are single tokens.
 	  ("..." (values :ellipsis nil))
+	  ("==" (values :eq))
+	  ("!=" (values :ne))
+	  ("<=" (values :le))
+	  (">=" (values :ge))
+	  ("&&" (values :and))
+	  ("||" (values :or))
+	  ("<<" (values :shl))
+	  (">>" (values :shr))
 
 	  ;; Any other character is punctuation.
 	  (:any (values it nil))