From 0ddfec9ac2783f59115205dc0f3806137265c59c Mon Sep 17 00:00:00 2001
From: adam <adam@megacz.com>
Date: Mon, 26 Mar 2007 01:43:10 -0400
Subject: [PATCH] throw error when Forest created with head()

darcs-hash:20070326054310-5007d-9ce12658982503cec80723b8b849f38103526abd.gz
---
 src/edu/berkeley/sbp/Forest.java |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/edu/berkeley/sbp/Forest.java b/src/edu/berkeley/sbp/Forest.java
index b2f4a22..1730f60 100644
--- a/src/edu/berkeley/sbp/Forest.java
+++ b/src/edu/berkeley/sbp/Forest.java
@@ -23,7 +23,7 @@ public abstract class Forest<NodeType> implements GraphViz.ToGraphViz {
     public void expand(HashSet<Tree<NodeType>> ht) { expand(ht, new HashSet<Forest<NodeType>>(), null); }
 
     static <NodeType> Forest<NodeType> create(Input.Region loc, NodeType head, Forest<NodeType>[] children, boolean lift) {
-        if (loc == null) throw new Error();
+        if (loc == null) throw new RuntimeException("invoked Forest.create(null,,,,) -- this should never happen");
         return new One<NodeType>(loc, head, children, lift);
     }
 
@@ -57,6 +57,7 @@ public abstract class Forest<NodeType> implements GraphViz.ToGraphViz {
         private One(Input.Region loc, NodeType head, Forest<NodeType>[] children, boolean lift) {
             this.location = loc;
             this.head = head;
+            if (head==null) throw new RuntimeException("invoked Forest.create(,null,,,) -- this should never happen");
             this.children = children==null ? emptyForestArray : new Forest[children.length];
             if (children != null) System.arraycopy(children, 0, this.children, 0, children.length);
             if (children != null) for(int i=0; i<children.length; i++) if (children[i]==null) throw new Error(i+"");
-- 
1.7.10.4