/**
* Returns an unevaluated term node if any. If none exists, <code>null<code> is returned
*
* @return <code>Node</code> representing a term node that has not been evaluated. If no such child exists, null is returned.
*/
public ASTNode getUnevaluatedTerm() {
// get first child
ASTNode child = this.getFirst();
// while the current child exists and has been evaluated, cycle to the next child
while (child != null && child.isEvaluated()) {
child = child.getNext();
}
// null will be returned when no children are left unevaluated, otherwise and unevaluated
// child node will be returned.
return child;
}
public Element interpretOperatorNode(Interpreter interpreter, ASTNode opNode)
throws InterpreterException {
Element result = null;
String x = opNode.getToken();
String gClass = opNode.getGrammarClass();
// if class of operator is binary
if (gClass.equals(ASTNode.BINARY_OPERATOR_CLASS)) {
// get operand nodes
ASTNode alpha = opNode.getFirst();
ASTNode beta = alpha.getNext();
// get operand values
Element l = alpha.getValue();
Element r = beta.getValue();
// if both operands are undef, the result is undef
if (l.equals(Element.UNDEF) && r.equals(Element.UNDEF)) {
capi.warning(
PLUGIN_NAME,
"Both operands of the '" + x + "' operator were undef.",
opNode,
interpreter);
result = Element.UNDEF;
} else
// confirm that at least one of the operands is a string elements, otherwise throw an error
if ((l instanceof StringElement || r instanceof StringElement)) {
if (x.equals(STRINGCONCAT_OP))
result = stringBackgroundElement.getNewValue(l.toString() + r);
}
// otherwise
// throw new InterpreterException("At least one operand must be strings for '"+x+"'
// operation.");
}
return result;
}