Implement MACROEXPAND-1.

2 files changed, 19 insertions, 0 deletions

diff --git a/MLKPackage.m b/MLKPackage.m
index 4673f0e..bb6e2db 100644
--- a/MLKPackage.m
+++ b/MLKPackage.m
@@ -99,6 +99,7 @@ static NSMutableDictionary *packages = nil;
   [sys export:[sys intern:@"MULTIPLY"]];
   [sys export:[sys intern:@"DIVIDE"]];
   [sys export:[sys intern:@"LIST"]];
+  [sys export:[sys intern:@"MACROEXPAND-1"]];
 
   [tlUser usePackage:clUser];
 }
diff --git a/MLKRoot.m b/MLKRoot.m
index cafafe1..a9e15d3 100644
--- a/MLKRoot.m
+++ b/MLKRoot.m
@@ -209,4 +209,22 @@ static id truify (BOOL value)
 {
   RETURN_VALUE ([MLKCons listWithArray:args]);
 }
+
++(NSArray *) macroexpand_1:(NSArray *)args
+{
+  id form = [args objectAtIndex:0];
+  id env = [args count] > 1 ? [args objectAtIndex:1] : nil;
+  MLKLexicalContext *context = env ? (id)env : (id)[MLKLexicalContext globalContext];
+
+  if ([context symbolNamesMacro:[form car]])
+    {
+      id <MLKFuncallable> macrofun = [context macroForSymbol:[form car]];
+      form = denullify ([[macrofun applyToArray:
+                                     [NSArray arrayWithObjects:
+                                                form, context, nil]]
+                          objectAtIndex:0]);
+    }
+
+  RETURN_VALUE (form);
+}
 @end