private TriggerAnnotation AnnotatePotentialCandidate(Expression expr)
{
bool expr_is_killer = false;
HashSet <OldExpr> oldExprSet;
if (cache.exprsInOldContext.TryGetValue(expr, out oldExprSet))
{
// oldExpr has been set to the value found
}
else
{
oldExprSet = null;
}
var new_exprs = TriggerUtils.MaybeWrapInOld(TriggerUtils.PrepareExprForInclusionInTrigger(expr, out expr_is_killer), oldExprSet);
// We expect there to be at least one "new_exprs".
// We also expect that the computation of new_term.Variables, collected_terms, and children_contain_killers will be the
// same for each of the "new_exprs".
// Therefore, we use the values of these variables from the last iteration in the expression that is ultimately returned.
TriggerTerm new_term = null;
List <TriggerTerm> collected_terms = null;
var children_contain_killers = false;
foreach (var new_expr in new_exprs)
{
new_term = new TriggerTerm {
Expr = new_expr, OriginalExpr = expr, Variables = CollectVariables(expr)
};
collected_terms = CollectExportedCandidates(expr);
children_contain_killers = CollectIsKiller(expr);
if (!children_contain_killers)
{
// Add only if the children are not killers; the head has been cleaned up into non-killer form
collected_terms.Add(new_term);
}
}
Contract.Assert(new_term != null); // this checks our assumption that "new_exprs" contains at least one value.
// This new node is a killer if its children were killers, or if it's non-cleaned-up head is a killer
return(new TriggerAnnotation(children_contain_killers || expr_is_killer, new_term.Variables, collected_terms));
}
internal static IEnumerable <TriggerMatch> SubexpressionsMatchingTrigger(this ComprehensionExpr quantifier, Expression trigger)
{
return(quantifier.AllSubExpressions(true, true, true)
.Select(e => TriggerUtils.PrepareExprForInclusionInTrigger(e).MatchAgainst(trigger, quantifier.BoundVars, e))
.Where(e => e.HasValue).Select(e => e.Value));
}