/* (non-Javadoc)
* @see org.coreasm.engine.Plugin#interpret(org.coreasm.engine.interpreter.Node)
*/
public ASTNode interpret(Interpreter interpreter, ASTNode pos) {
ASTNode nextPos = pos;
String x = pos.getToken();
String gClass = pos.getGrammarClass();
// if number related expression
if (gClass.equals(ASTNode.EXPRESSION_CLASS)) {
// it is a number constant
if (x != null) {
// get new string element representing lexeme from string background
StringElement se = stringBackgroundElement.getNewValue(x);
// result of this node is the string element produced
pos.setNode(null, null, se);
}
}
return nextPos;
}
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;
}