Added syntax evaluation for asm lines

1 files changed, 54 insertions, 0 deletions

diff --git a/grammar.lisp b/grammar.lisp
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index 0000000..2a3cb03
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+++ b/grammar.lisp
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+;; -*- 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*)
+