Added syntax evaluation for asm lines

3 files changed, 75 insertions, 17 deletions

diff --git a/6502.lisp b/6502.lisp
index 1e9c7d4..7c0c2a7 100644
--- a/6502.lisp
+++ b/6502.lisp
@@ -202,6 +202,22 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
    (NOP 234 (implied))
    (BRK   0 (implied))))
 
+
+
+(defun extract-keys (list)
+  "Extract the keys of associative lists."
+  (let ((ret nil))
+	(progn
+	  (dolist (i list)
+		(setf ret
+			  (cons (car i) ret)))
+	  (reverse ret))))
+
+;; Generated list of opcodes.
+(setf
+ *opcodes*
+ (extract-keys *instructions*))
+
 (defun valid-instruction? (instruction addressing-mode)
   "Is instruction and addressing mode combination correct?"
   (cond
diff --git a/grammar.lisp b/grammar.lisp
new file mode 100644
index 0000000..2a3cb03
--- /dev/null
+++ b/grammar.lisp
@@ -0,0 +1,54 @@
+;; -*- mode: common-lisp -*-
+#|
+clasm-6502: An assembler for the 6502 written in Common Lisp.
+Copyright (C) 2024  Aleksei Eaves
+
+This library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Lesser General Public
+License as published by the Free Software Foundation; either
+version 2.1 of the License, or (at your option) any later version.
+
+This library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public
+License along with this library; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+|#
+
+(defun last-char (s)
+  (char s (- (length s) 1)))
+
+(setf
+ *grammar*
+ '((label
+	(lambda (l)
+	  (eq (last-char (first l)) #\:)))
+   (macro
+	(lambda (l)
+	  (eq (second l) "=")))
+   (attribute
+	(lambda (l)
+	  (eq (char (first l) 0) #\.)))
+   (instruction
+	(lambda (l)
+	  (if (or (member (read-from-string (first l)) *opcodes*)
+			  (member (read-from-string (second l)) *opcodes*))
+		  t nil)))))
+
+
+(defun syntax-rule (item list)
+  "Test a line against a list of syntax rules."
+  (dolist (i (extract-keys list))	
+	(let ((z (funcall
+			  (eval (cadr (assoc i list)))
+			  item)))
+	  (cond ((not (equal
+				   z nil))
+			 (return i))
+			(t nil)))))
+
+(syntax-rule '("LDA:" "$05") *grammar*)
+
diff --git a/main.lisp b/main.lisp
index adeaf15..1c16b31 100644
--- a/main.lisp
+++ b/main.lisp
@@ -18,21 +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
 |#
 
+#|
+To solve the problem of the colliding syntax rules
+We can test only the addressin modes we know the opcode to have
+This not only solves this problem, it just makes more sense.
+|#
 
-(defun last-char (s)
-  (char s (- (length s) 1)))
-
-(defun label? (s)
-  (eq (last-char s) #\:))
-
-
-(setf
- *grammar*
- (('label
-   (lambda (l)
-	 ))))
-
-(defun read_code ()
-  (incf *source-line-number*)
-  ()
-  )