;; -*- 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 extract-keys (alist) "Extract the keys of associative lists." (let ((return-value nil)) (progn (dolist (i alist) (setf return-value (cons (car i) return-value))) (reverse return-value)))) (defun hexd? (string) "Is a string a hexd number?" (let ((stack ())) (dotimes (i (length string)) (push (or (and (char-not-lessp (char string i) #\0) (char-not-greaterp (char string i) #\9)) (and (char-not-lessp (char string i) #\A) (char-not-greaterp (char string i) #\F))) stack)) (push 'and stack) (eval stack))) (defun hex2dec (string) "Convert an arbitrarily sized hexd number (as string) to a positive decimal." (if (hexd? string) (flet ((hex (c) ;Return character as hexadecimal (cond ((and (char-not-lessp c #\0) (char-not-greaterp c #\9)) (- (char-code c) (char-code #\0))) ((and (char-not-lessp c #\A) (char-not-greaterp c #\F)) (+ (- (char-code (char-downcase c)) (char-code #\a)) 10))))) (let ((return-value 0)) (do ((i 0 (incf i)) (j (- (length string) 1) (decf j))) ((minusp j) ()) (setf return-value (+ return-value (* (expt 16 j) (hex (char string i)))))) return-value)) nil))