/**
* 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;
}
/* (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;
}
@Override
public void compile(CodeFragment result, ASTNode node, CompilerEngine engine)
throws CompilerException {
System.out.println("called, father is " + node.getParent());
try {
LetRuleNode letrule = (LetRuleNode) node;
Map<String, ASTNode> letmap = letrule.getVariableMap();
result.appendLine("//start of let\n");
result.appendLine("localStack.pushLayer();\n");
for (Entry<String, ASTNode> entry : letmap.entrySet()) {
CodeFragment val = engine.compile(entry.getValue(), CodeType.R);
result.appendFragment(val);
result.appendLine("localStack.put(\"" + entry.getKey() + "\", evalStack.pop());\n");
}
result.appendFragment(engine.compile(letrule.getInRule(), CodeType.U));
result.appendLine("localStack.popLayer();\n");
result.appendLine("//end of let\n");
} catch (Exception e) {
throw new CompilerException(e);
}
}