/**
* Replace all references to the variable bound by this let expression, that occur within the
* action expression, with the given expression
*
* @param opt The optimizer
* @param seq the expression
* @throws net.sf.saxon.trans.XPathException
*/
public void replaceVariable(Optimizer opt, Expression seq) throws XPathException {
PromotionOffer offer2 = new PromotionOffer(opt);
offer2.action = PromotionOffer.INLINE_VARIABLE_REFERENCES;
offer2.bindingList = new Binding[] {this};
offer2.containingExpression = seq;
action = doPromotion(action, offer2);
if (offer2.accepted) {
// there might be further references to the variable
offer2.accepted = false;
replaceVariable(opt, seq);
}
if (isIndexedVariable() && seq instanceof VariableReference) {
Binding newBinding = ((VariableReference) seq).getBinding();
if (newBinding instanceof Assignation) {
((Assignation) newBinding).setIndexedVariable();
}
}
}
/** Promote this expression if possible */
public Expression promote(PromotionOffer offer) throws XPathException {
Expression exp = offer.accept(this);
if (exp != null) {
return exp;
} else {
if (offer.action != PromotionOffer.UNORDERED) {
// we can't push the UNORDERED property down to the operand, because order is significant
operand = doPromotion(operand, offer);
}
return this;
}
}
/** Promote this expression if possible */
public Expression promote(PromotionOffer offer, Expression parent) throws XPathException {
Expression exp = offer.accept(parent, this);
if (exp != null) {
return exp;
} else {
if (offer.action != PromotionOffer.UNORDERED) {
operand0 = doPromotion(this, operand0, offer);
operand1 = doPromotion(this, operand1, offer);
}
return this;
}
}
/** Promote this expression if possible */
public Expression promote(PromotionOffer offer, Expression parent) throws XPathException {
Expression exp = offer.accept(parent, this);
if (exp != null) {
return exp;
} else {
sequence = doPromotion(sequence, offer);
if (offer.action == PromotionOffer.INLINE_VARIABLE_REFERENCES
|| offer.action == PromotionOffer.UNORDERED
|| offer.action == PromotionOffer.REPLACE_CURRENT) {
action = doPromotion(action, offer);
} else if (offer.action == PromotionOffer.RANGE_INDEPENDENT
|| offer.action == PromotionOffer.FOCUS_INDEPENDENT) {
// Pass the offer to the action expression only if the action isn't dependent on the
// variable bound by this assignation
Binding[] savedBindingList = offer.bindingList;
offer.bindingList = extendBindingList(offer.bindingList);
action = doPromotion(action, offer);
offer.bindingList = savedBindingList;
}
return this;
}
}