Add class MLKNumber, unify arithmetic interface.

1 files changed, 35 insertions, 0 deletions

diff --git a/MLKNumber.m b/MLKNumber.m
new file mode 100644
index 0000000..8ffc0f8
--- /dev/null
+++ b/MLKNumber.m
@@ -0,0 +1,35 @@
+/* -*- mode: objc; coding: utf-8 -*- */
+/* Étoilisp/Mulklisp, a Common Lisp subset for the Étoilé runtime.
+ * Copyright (C) 2008  Matthias Andreas Benkard.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#import "MLKNumber.h"
+
+
+@implementation MLKNumber
+#define DECLARE_ABSTRACT(SIGNATURE, RETURN_VALUE)                       \
+SIGNATURE                                                             \
+{                                                                     \
+  [NSException raise:@"MLKInternalInconsistencyError"                 \
+              format:@"Tried to invoke an abstract method."];        \
+                return RETURN_VALUE;                                                \
+}
+
+DECLARE_ABSTRACT (-(MLKNumber *) add:(MLKNumber *)arg, nil)
+DECLARE_ABSTRACT (-(MLKNumber *) subtract:(MLKNumber *)arg, nil)
+DECLARE_ABSTRACT (-(MLKNumber *) multiplyWith:(MLKNumber *)arg, nil)
+DECLARE_ABSTRACT (-(MLKNumber *) divideBy:(MLKNumber *)arg, nil)
+@end