/** Compiles ParameterExpressions */
@Override
public void visit(ParameterExpression param) {
if (param == null) {
throw new ArgumentException(PARAMETER + E_IS_NULL);
}
if (parameters.containsKey(param.getName())) {
/** If the parameter itself is and expression */
if (parameters.get(param.getName()) instanceof ExpressionCompiler) {
// The parameter is itself another Expression
ExpressionCompiler expr = (ExpressionCompiler) parameters.get(param.getName());
expr.setParameters(parameters);
expr.setMethodResolver(getMethodResolver());
expr.setParameterizedResolver(getParameterizedResolver());
// TODO: Need a way to pass in the compile type here, maybe from
// global scope of API call for compile...
result.setResult(
(LogicalExpression) ((ExpressionCompiler) parameters.get(param.getName())).compile());
} else {
result.setResult((LogicalExpression) parameters.get(param.getName()));
}
} else {
ParameterizedArgs args = new ParameterizedArgs(result, param.getName());
resolveParameterizedReference(args);
if (args.getResult() == null)
throw new CompilationException(
String.format(E_PARAMETER_S_WAS_NOT_DEFINED, param.getName()));
result.setResult((LogicalExpression) args.getResult());
}
}
/** Compiles MethodExpressions */
@Override
public void visit(MethodExpression method) {
if (method == null) {
throw new ArgumentException(METHOD + E_IS_NULL);
}
LogicalExpression[] parameters = new LogicalExpression[method.getParameters().length];
for (int i = 0; i < parameters.length; i++) {
parameters[i] = evaluate(method.getParameters()[i]);
}
MethodArgs args = new MethodArgs(method.getName());
args.setParameters(parameters);
resolveMethod(args);
// If an external implementation was found get the result back
if (args.getResult() != null) {
result.setResult((LogicalExpression) args.getResult());
return;
}
defaultMethodResolver.resolve(args);
result.setResult((LogicalExpression) args.getResult());
}
/** Compiles UnaryExpression */
@Override
public void visit(UnaryExpression expression) {
if (expression == null) {
throw new ArgumentException(EXPRESSION + E_IS_NULL);
}
expression.getExpression().accept(this);
switch (expression.getType()) {
case NOT:
result.setResult(new Not(result.getResult()));
break;
case NEGATE:
result.setResult(new Negate(result.getResult()));
break;
}
}
@Override
public void visit(AssignmentExpression assignment) {
if (assignment == null) {
throw new ArgumentException(ASSIGNMENT + E_IS_NULL);
}
/** processes the left hand expression and saves the value to result */
assignment.getLeft().accept(this);
LogicalExpression left = result.getResult();
// LHS must always be a variable.
if (!(left instanceof Variable)) {
throw new ArgumentException(E_ASSIGNMENT_LHS_NOT_VARIABLE);
}
assignment.setLeft(left);
/** processes the right hand expression and saves the value to result */
assignment.getRight().accept(this);
assignment.setRight(result.getResult());
/** No magic here, just set the original instance */
result.setResult(assignment);
}
/** Compiles ValueExpressions */
@Override
public void visit(ValueExpression expression) {
if (expression == null) {
throw new ArgumentException(EXPRESSION + E_IS_NULL);
}
// FIXME: Treat all numerics as BigDecimal or better yet, MutableDecimal
// Also - what other types must we handle?
// BYTE? BYTEARRAY? CHARACTER?
switch (expression.getType()) {
case BOOLEAN:
result.setResult(
new Literal<Boolean>(ValueType.BOOLEAN, Boolean.parseBoolean(expression.getText())));
break;
case DATETIME:
result.setResult(
new Literal<DateTime>(
ValueType.DATETIME,
// DateTime.parse(expression.getText().substring(1,
// expression.getText().length() - 2))));
DateTime.parse(expression.getText())));
break;
case INTEGER:
case DECIMAL:
result.setResult(
new Literal<Double>(ValueType.DECIMAL, Convert.parseNumeric(expression.getText())));
break;
case TEXT:
result.setResult(new Literal<String>(ValueType.TEXT, expression.getText()));
break;
case VARIABLE:
Variable var = new Variable(expression.getText());
// Record for easy update before compute
result.addOrUpdateVariable(var);
result.setResult(var);
break;
}
}
private LogicalExpression evaluate(LogicalExpression expression) {
expression.accept(this);
return result.getResult();
}
/** Compiles BinaryExpressions */
@Override
public void visit(BinaryExpression expression) {
if (expression == null) {
throw new ArgumentException(EXPRESSION + E_IS_NULL);
}
/** processes the left hand expression and saves the value to result */
expression.getLeft().accept(this);
LogicalExpression left = result.getResult();
/** processes the right hand expression and saves the value to result */
expression.getRight().accept(this);
LogicalExpression right = result.getResult();
switch (expression.getType()) {
case AND:
result.setResult(new And(left, right));
break;
case OR:
result.setResult(new Or(left, right));
break;
case DIV:
result.setResult(new Divide(left, right));
break;
case EQ:
result.setResult(new Equal(left, right));
break;
case GT:
result.setResult(new Greater(left, right));
break;
case GTE:
result.setResult(new GreaterEqual(left, right));
break;
case LT:
result.setResult(new Lesser(left, right));
break;
case LTE:
result.setResult(new LesserEqual(left, right));
break;
case MINUS:
result.setResult(new Minus(left, right));
break;
case MOD:
result.setResult(new Modulo(left, right));
break;
case NE:
result.setResult(new NotEqual(left, right));
break;
case PLUS:
result.setResult(new Plus(left, right));
break;
case MULT:
result.setResult(new Multiply(left, right));
break;
case POW:
result.setResult(new Power(left, right));
break;
}
}