func (this *JSConverter) VisitLT(expr *expression.LT) (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
}
func newSargLT(pred *expression.LT) *sargLT {
rv := &sargLT{}
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) {
exprs = expression.Expressions{pred.Second().Static()}
span.Range.High = exprs
} else if pred.Second().EquivalentTo(expr2) {
exprs = expression.Expressions{pred.First().Static()}
span.Range.Low = exprs
} else {
return nil, nil
}
if len(exprs) == 0 || exprs[0] == nil {
return nil, nil
}
span.Range.Inclusion = datastore.NEITHER
return plan.Spans{span}, nil
}
return rv
}
func (this *subsetLT) VisitLT(expr *expression.LT) (interface{}, error) {
if this.lt.First().EquivalentTo(expr.First()) {
return LessThanOrEquals(this.lt.Second(), expr.Second()), nil
}
if this.lt.Second().EquivalentTo(expr.Second()) {
return LessThanOrEquals(expr.First(), this.lt.First()), nil
}
return false, nil
}