From 9960b8e94943867cc321a5145c327188e14d4d44 Mon Sep 17 00:00:00 2001
From: Matthias Andreas Benkard <matthias@benkard.de>
Date: Sun, 22 Jun 2008 13:19:09 +0200
Subject: Add class MLKInterpreter.

---
 MLKInterpreter.m | 146 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 146 insertions(+)
 create mode 100644 MLKInterpreter.m

(limited to 'MLKInterpreter.m')

diff --git a/MLKInterpreter.m b/MLKInterpreter.m
new file mode 100644
index 0000000..37da36d
--- /dev/null
+++ b/MLKInterpreter.m
@@ -0,0 +1,146 @@
+/* -*- 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 "MLKCons.h"
+#import "MLKDynamicContext.h"
+#import "MLKEnvironment.h"
+#import "MLKFuncallable.h"
+#import "MLKInterpreter.h"
+#import "MLKLexicalContext.h"
+#import "MLKPackage.h"
+#import "MLKSymbol.h"
+#import "runtime-compatibility.h"
+
+#import <Foundation/NSArray.h>
+#import <Foundation/NSString.h>
+
+
+static MLKPackage *cl;
+static MLKPackage *sys;
+static MLKSymbol *IF;
+static MLKSymbol *PROGN;
+static MLKSymbol *TAGBODY;
+static MLKSymbol *GO;
+static MLKSymbol *CATCH;
+static MLKSymbol *THROW;
+static MLKSymbol *LAMBDA;
+static MLKSymbol *LET;
+static MLKSymbol *APPLY;
+static MLKSymbol *FUNCALL;
+static MLKSymbol *EVAL;
+static MLKSymbol *_DEFMACRO;
+
+
+@implementation MLKInterpreter
++(void) initialize
+{
+  cl = [MLKPackage findPackage:@"COMMON-LISP"];
+  sys = [MLKPackage findPackage:@"TOILET-SYSTEM"];
+
+  IF = [cl intern:@"IF"];
+  PROGN = [cl intern:@"PROGN"];
+  TAGBODY = [cl intern:@"TAGBODY"];
+  GO = [cl intern:@"GO"];
+  CATCH = [cl intern:@"CATCH"];
+  THROW = [cl intern:@"THROW"];
+  LAMBDA = [cl intern:@"LAMBDA"];
+  LET = [cl intern:@"LET"];
+  APPLY = [cl intern:@"APPLY"];
+  EVAL = [cl intern:@"EVAL"];
+  _DEFMACRO = [sys intern:@"%DEFMACRO"];
+}
+
+
++(id) eval:(id)program
+      inLexicalContext:(MLKLexicalContext *)context
+      withEnvironment:(MLKEnvironment *)lexenv
+{
+  MLKDynamicContext *dynamicContext = [MLKDynamicContext currentContext];
+
+  if (!program || [program isKindOfClass:[MLKSymbol class]])
+    {
+      if ([context variableIsLexical:program])
+        {
+          return [lexenv valueForBinding:program];
+        }
+      else
+        {
+          return [dynamicContext valueForBinding:program];
+        }
+    }
+  else if (![program isKindOfClass:[MLKCons class]])
+    {
+      // Everything that is not a list or a symbol evaluates to itself.
+      return program;
+    }
+  else
+    {
+      id car = [program car];
+
+      if ([car isKindOfClass:[MLKSymbol class]])
+        {
+          if (car == APPLY)
+            {
+              MLKCons *rest = [self eval:[[[program cdr] cdr] car]
+                                    inLexicalContext:context
+                                    withEnvironment:lexenv];
+
+              return [[[program cdr] car] applyToArray:(rest
+                                                        ? [rest array]
+                                                        : [NSArray array])];
+            }
+          else if (car == EVAL)
+            {
+              return [self eval:[self eval:[program cdr]
+                                      inLexicalContext:context
+                                      withEnvironment:lexenv]
+                           inLexicalContext:[MLKLexicalContext nullContext]
+                           withEnvironment:
+                             AUTORELEASE([[MLKEnvironment alloc] init])];
+            }
+          else if (car == PROGN)
+            {
+              id result;
+              id rest = program;
+              while ((rest = [rest cdr]))
+                {
+                  result = [self eval:[rest car]
+                                 inLexicalContext:context
+                                 withEnvironment:lexenv];
+                }
+
+              return result;
+            }
+          else if (car == TAGBODY)
+            {
+              //FIXME: ...
+            }
+          else
+            {
+              //FIXME: ...
+            }
+        }
+      else if (![car isKindOfClass:[MLKCons class]] && [car car] == LAMBDA)
+        {
+          return [self eval:[MLKCons cons:FUNCALL with:program]
+                       inLexicalContext:context
+                       withEnvironment:lexenv];
+        }
+    }
+}
+@end
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