fix http://arclanguage.org/item?id=12542 (rocketnia) - handles empty …

…bracket-fn []
conanite · Oct 12, 2010 · aa37d65 · aa37d65
1 parent d792435
commit aa37d65
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Showing 3 changed files with 16 additions and 17 deletions.
diff --git a/src/arc/lib/tests/core-evaluation-test.arc b/src/arc/lib/tests/core-evaluation-test.arc
@@ -5,14 +5,15 @@
     (suite "[ _ ] shortcut"
       ("call directly"
         ([* _ _] 15)
-        225
-      )
+        225)
 
       ("useful in apply"
         (apply [* _ _] '(16))
-        256
-      )
-    )
+        256)
+
+      ("handles empty bracket-fn"
+        ([] 21)
+        nil))
 
     (suite "apply"
       ("a simple sum function"

diff --git a/src/cc/ArcParser.jj b/src/cc/ArcParser.jj
@@ -194,7 +194,7 @@ ArcObject functionShortcut(): {
                               } {
   tok = "[" (
   o = expression()            { list.add(o); }
-  )+ "]"                      {
+  )* "]"                      {
                                 fn.add(Pair.buildFrom(list));
                                 return Pair.buildFrom(fn);
                               }

diff --git a/src/java/rainbow/functions/interpreted/InterpretedFunction.java b/src/java/rainbow/functions/interpreted/InterpretedFunction.java
@@ -5,21 +5,15 @@
 import rainbow.LexicalClosure;
 import rainbow.Nil;
 import rainbow.functions.Builtin;
-import rainbow.types.ArcObject;
-import rainbow.types.ArcString;
-import rainbow.types.Pair;
-import rainbow.types.Symbol;
+import rainbow.types.*;
 import rainbow.vm.Instruction;
 import rainbow.vm.VM;
 import rainbow.vm.compiler.FunctionBodyBuilder;
 import rainbow.vm.compiler.FunctionParameterListBuilder;
 import rainbow.vm.instructions.Close;
 import rainbow.vm.instructions.Literal;
 import rainbow.vm.instructions.PopArg;
-import rainbow.vm.interpreter.BoundSymbol;
-import rainbow.vm.interpreter.IfClause;
-import rainbow.vm.interpreter.Quotation;
-import rainbow.vm.interpreter.StackSymbol;
+import rainbow.vm.interpreter.*;
 import rainbow.vm.interpreter.visitor.FunctionOwnershipVisitor;
 import rainbow.vm.interpreter.visitor.MeasureLexicalReach;
 import rainbow.vm.interpreter.visitor.ReferenceCounter;
@@ -332,8 +326,12 @@ public int compareTo(ArcObject right) {
 
   public String toString() {
     if (isBracketFn()) {
-      String s = body[0].toString();
-      return "[" + s.substring(1, s.length() - 1) + "]";
+      if (body[0] instanceof Nil) {
+        return "[]";
+      } else {
+        String s = body[0].toString();
+        return "[" + s.substring(1, s.length() - 1) + "]";
+      }
     }
     List<ArcObject> fn = new LinkedList<ArcObject>();
     fn.add(Symbol.mkSym("fn"));
@@ -343,7 +341,7 @@ public String toString() {
   }
 
   private boolean isBracketFn() {
-    return parameterList instanceof Pair && parameterList.car() == Symbol.mkSym("_") && parameterList.cdr() instanceof Nil && body.length == 1;
+    return parameterList instanceof Pair && parameterList.car() == Symbol.mkSym("_") && parameterList.cdr() instanceof Nil && body.length == 1 && !(body[0] instanceof LiteralObject);
   }
 
   public ArcObject parameterList() {