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 (this *JSConverter) VisitEq(expr *expression.Eq) (interface{}, error) {
var buf bytes.Buffer
buf.WriteString("(")
buf.WriteString(this.Visit(expr.First()))
buf.WriteString(" == ")
buf.WriteString(this.Visit(expr.Second()))
buf.WriteString(")")
return buf.String(), nil
}