Some housekeeping

1 files changed, 84 insertions, 16 deletions

diff --git a/grammar.lisp b/grammar.lisp
index d91317f..f0c0e10 100644
--- a/grammar.lisp
+++ b/grammar.lisp
@@ -18,9 +18,9 @@ License along with this library; if not, write to the Free Software
 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 |#
 
-;; Rules for interpreting the purpose of some line.
-(setf
- *grammar*
+;; Rules for the interpretation of lines.
+(defparameter
+ *line-syntax*
  '(
    (label
 	(lambda (l)
@@ -43,6 +43,87 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 	(lambda (l)
 	  t))))
 
+;; Rules for identifying addressing modes.
+(defparameter
+ *addressing-modes-syntax*
+ '((immediate ; #?? ... more complex syntax rules for later
+	(lambda (s)
+	  (eq "#" (subseq s 0 1))))
+   (absolute ;"$????"
+	(lambda (s)
+	  (and
+	   (equal (length s) 5)
+	   (equal "$" (subseq s 0 1))
+	   (hexd? (subseq s 1 5)))))
+   (zero-page ;"$??"
+	(lambda (s)
+	  (and
+	   (equal (length s) 3)
+	   (equal "$" (subseq s 0 1))
+	   (hexd? (subseq s 1 3)))))
+   (implied nil)
+   (indirect-absolute ;($????)
+	(lambda (s)
+	  (and
+	   (equal (length s) 7)
+	   (equal "($" (subseq s 0 2))
+	   (hexd? (subseq s 1 5))
+	   (equal ")" (subseq s 5 6)))))
+   (absolute-indexed-x ;"$????,X"
+	(lambda (s)
+	  (and
+	   (equal (length s) 7)
+	   (equal "$" (subseq s 0 1))
+	   (hexd? (subseq s 1 5))
+	   (equal ",X" (subseq s 5 7)))))
+   (absolute-indexed-y ;"$????,Y"
+	(lambda (s)
+	  (and
+	   (equal (length s) 7)
+	   (equal "$" (subseq s 0 1))
+	   (hexd? (subseq s 1 5))
+	   (equal ",Y" (subseq s 5 7)))))
+   (zero-page-indexed-x ;"$??,X"
+	(lambda (s)
+	  (and
+	   (equal (length s) 5)
+	   (equal (subseq s 0 1) "$")
+	   (hexd? (subseq s 1 3))
+	   (equal (subseq s 3 5) ",X"))))
+   (zero-page-indexed-y ;"$??,Y"
+	(lambda (s)
+	  (and
+	   (equal (length s) 5)
+	   (equal (subseq s 0 1) "$")
+	   (hexd? (subseq s 1 3))
+	   (equal (subseq s 3 5) ",Y"))))
+   (indexed-indirect ;"($??,X)"
+	(lambda (s)
+	  (and
+	   (equal (length s) 7)
+	   (equal (subseq s 0 2) "($")
+	   (hexd? (subseq s 2 4))
+	   (equal (subseq s 4 7) ",X)"))))
+   (indirect-indexed ;"($??),Y"
+	(lambda (s)
+	  (and
+	   (equal (length s) 7)
+	   (equal (subseq s 0 2) "($")
+	   (hexd? (subseq s 2 4))
+	   (equal (subseq s 4 7) "),Y"))))
+   ;;How to fix that relative and absolute are the same rule?
+   ;;A check upstream would suffice.
+   (relative ;"$????"
+	(lambda (s)
+	  (and
+	   (equal (length s) 5)
+	   (equal (subseq s 0 1) "$")
+	   (hexd? (subseq s 1 5)))))
+   (accumulator ;"A"
+	(lambda (s)
+	  (and
+	   (equal (length s) 1)
+	   (equal "A" (subseq s 0 1)))))))
 
 (defun syntax-rule (line list)
   "Apply a syntax rule against a delimited line from a program."
@@ -53,16 +134,3 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 				z nil))
 		  (return i)
 		  nil))))
-
-
-(syntax-rule '("LABEL:" "LDA" "$05") *grammar*)
-
-(syntax-rule '("LDA" "$05") *grammar*)
-
-(syntax-rule '("AS" "=" "THAT") *grammar*)
-
-(syntax-rule '("LABEL:") *grammar*)
-
-(syntax-rule '("hhhh") *grammar*)
-
-(syntax-rule '(".org" "$FF00") *grammar*)