func newSargDefault(expr expression.Expression) *sargDefault {
var spans Spans
if expr.PropagatesNull() {
spans = _VALUED_SPANS
} else if expr.PropagatesMissing() {
spans = _FULL_SPANS
}
rv := &sargDefault{}
rv.sarg = func(expr2 expression.Expression) (Spans, error) {
if expr.EquivalentTo(expr2) {
return _SELF_SPANS, nil
}
if spans != nil && expr.DependsOn(expr2) {
return _VALUED_SPANS, nil
}
if spans != nil && expr.DependsOn(expr2) {
return _FULL_SPANS, nil
}
return nil, nil
}
return rv
}
func newSargableDefault(expr expression.Expression) *sargableDefault {
rv := &sargableDefault{}
rv.test = func(expr2 expression.Expression) (bool, error) {
return expr.EquivalentTo(expr2), nil
}
return rv
}
func newSubsetDefault(expr expression.Expression) *subsetDefault {
rv := &subsetDefault{}
rv.test = func(expr2 expression.Expression) (bool, error) {
value2 := expr2.Value()
if value2 != nil {
return value2.Truth(), nil
}
if expr.EquivalentTo(expr2) {
return true, nil
}
switch expr2 := expr2.(type) {
case *expression.And:
for _, op := range expr2.Operands() {
if !SubsetOf(expr, op) {
return false, nil
}
}
return true, nil
case *expression.Or:
for _, op := range expr2.Operands() {
if SubsetOf(expr, op) {
return true, nil
}
}
return false, nil
case *expression.IsNotMissing:
return expr.PropagatesMissing() &&
expr.DependsOn(expr2.Operand()), nil
case *expression.IsNotNull:
return expr.PropagatesNull() &&
expr.DependsOn(expr2.Operand()), nil
case *expression.IsValued:
return expr.PropagatesNull() &&
expr.DependsOn(expr2.Operand()), nil
}
return false, nil
}
return rv
}
func LessThanOrEquals(expr1, expr2 expression.Expression) bool {
return LessThan(expr1, expr2) || expr1.EquivalentTo(expr2)
}