func newSargAnd(expr *expression.And) *sargAnd {
rv := &sargAnd{}
rv.sarg = func(expr2 expression.Expression) (spans Spans, err error) {
if expr.EquivalentTo(expr2) {
return _SELF_SPANS, nil
}
for _, op := range expr.Operands() {
s := SargFor(op, expr2)
if s == nil {
continue
}
if spans == nil {
spans = s
} else {
spans = constrain(spans, s)
}
}
return
}
return rv
}
