checkpoint

[sbp.git] / src / edu / berkeley / sbp / util / TreeBuilder.java

diff --git a/src/edu/berkeley/sbp/util/TreeBuilder.java b/src/edu/berkeley/sbp/util/TreeBuilder.java
new file mode 100644 (file)
index 0000000..fbdd107
--- /dev/null
+++ b/src/edu/berkeley/sbp/util/TreeBuilder.java
@@ -0,0 +1,23 @@
+package edu.berkeley.sbp.util;
+import edu.berkeley.sbp.*;
+import java.util.*;
+
+public abstract class TreeBuilder<T> implements Invokable<Forest.Body<T>,Boolean,Integer> {
+    public ArrayList<Tree<T>> toks = new ArrayList<Tree<T>>();
+    public boolean toss;
+    protected T head;
+    public TreeBuilder(boolean toss) { this.toss = toss; }
+    public abstract void start(T head, Input.Location loc);
+    public abstract void finish(T head, Input.Location loc);
+    public abstract void addTree(Tree<T> t);
+    public void invoke(Forest.Body<T> bod, Boolean o, Integer i) {
+        if (i==null) {
+            ArrayList<Tree<T>> toks = this.toks;
+            this.toks = new ArrayList<Tree<T>>();
+            bod.expand(0, this);
+            this.toks = toks;
+        } else {
+            bod.expand(i, this);
+        }
+    }
+}