superclass for logical functions

git-svn-id: https://svn.apache.org/repos/asf/jakarta/poi/trunk@479294 13f79535-47bb-0310-9956-ffa450edef68

src/scratchpad/src/org/apache/poi/hssf/record/formula/functions/LogicalFunction.java

@@ -0,0 +1,31 @@
+/*
+ * Created on Nov 25, 2006
+ *
+ */
+package org.apache.poi.hssf.record.formula.functions;
+
+import org.apache.poi.hssf.record.formula.eval.RefEval;
+import org.apache.poi.hssf.record.formula.eval.ValueEval;
+
+/**
+ * @author Amol S. Deshmukh < amolweb at ya hoo dot com >
+ *
+ */
+public abstract class LogicalFunction implements Function {
+
+    /**
+     * recursively evaluate any RefEvals
+     * @param reval
+     * @return
+     */
+    protected ValueEval xlateRefEval(RefEval reval) {
+        ValueEval retval = (ValueEval) reval.getInnerValueEval();
+        
+        if (retval instanceof RefEval) {
+            RefEval re = (RefEval) retval;
+            retval = xlateRefEval(re);
+        }
+
+        return retval;
+    }
+}