func newSargEq(pred *expression.Eq) *sargEq {
rv := &sargEq{}
rv.sarger = func(expr2 expression.Expression) (plan.Spans, error) {
if SubsetOf(pred, expr2) {
return _SELF_SPANS, nil
}
span := &plan.Span{}
if pred.First().EquivalentTo(expr2) {
span.Range.Low = expression.Expressions{pred.Second().Static()}
} else if pred.Second().EquivalentTo(expr2) {
span.Range.Low = expression.Expressions{pred.First().Static()}
} else {
return nil, nil
}
if span.Range.Low[0] == nil {
return nil, nil
}
if rv.MissingHigh() {
span.Range.High = expression.Expressions{expression.NewSuccessor(span.Range.Low[0])}
span.Range.Inclusion = datastore.LOW
} else {
span.Range.High = span.Range.Low
span.Range.Inclusion = datastore.BOTH
}
return plan.Spans{span}, nil
}
return rv
}
func newSargLE(pred *expression.LE) *sargLE {
rv := &sargLE{}
rv.sarger = func(expr2 expression.Expression) (plan.Spans, error) {
if SubsetOf(pred, expr2) {
return _SELF_SPANS, nil
}
var exprs expression.Expressions
span := &plan.Span{}
if pred.First().EquivalentTo(expr2) {
hs := pred.Second().Static()
if hs != nil {
if rv.MissingHigh() {
exprs = expression.Expressions{expression.NewSuccessor(hs)}
} else {
exprs = expression.Expressions{hs}
span.Range.Inclusion = datastore.HIGH
}
span.Range.High = exprs
}
} else if pred.Second().EquivalentTo(expr2) {
exprs = expression.Expressions{pred.First().Static()}
span.Range.Low = exprs
span.Range.Inclusion = datastore.LOW
} else {
return nil, nil
}
if len(exprs) == 0 || exprs[0] == nil {
return nil, nil
}
return plan.Spans{span}, nil
}
return rv
}