/**
* Returns the step in an expression of the form 'step = value'. Null is returned if the
* expression is not of the right form. Optimization if off if null is returned.
*/
public Step getStep() {
// Returned cached value if called more than once
if (_step != null) {
return _step;
}
// Nothing to do if _exp is null
if (_exp == null) {
return null;
}
// Ignore if not equality expression
if (_exp instanceof EqualityExpr) {
EqualityExpr exp = (EqualityExpr) _exp;
Expression left = exp.getLeft();
Expression right = exp.getRight();
// Unwrap and set _step if appropriate
if (left instanceof CastExpr) {
left = ((CastExpr) left).getExpr();
}
if (left instanceof Step) {
_step = (Step) left;
}
// Unwrap and set _step if appropriate
if (right instanceof CastExpr) {
right = ((CastExpr) right).getExpr();
}
if (right instanceof Step) {
_step = (Step) right;
}
}
return _step;
}
/**
* Returns the value in an expression of the form 'step = value'. A value may be either a literal
* string or a variable whose type is string. Optimization if off if null is returned.
*/
public Expression getCompareValue() {
// Returned cached value if called more than once
if (_value != null) {
return _value;
}
// Nothing to to do if _exp is null
if (_exp == null) {
return null;
}
// Ignore if not an equality expression
if (_exp instanceof EqualityExpr) {
EqualityExpr exp = (EqualityExpr) _exp;
Expression left = exp.getLeft();
Expression right = exp.getRight();
// Return if left is literal string
if (left instanceof LiteralExpr) {
_value = left;
return _value;
}
// Return if left is a variable reference of type string
if (left instanceof VariableRefBase && left.getType() == Type.String) {
_value = left;
return _value;
}
// Return if right is literal string
if (right instanceof LiteralExpr) {
_value = right;
return _value;
}
// Return if left is a variable reference whose type is string
if (right instanceof VariableRefBase && right.getType() == Type.String) {
_value = right;
return _value;
}
}
return null;
}
public void flushCache() {
super.flushCache();
}