Function DatumNext

pkg/sql/sem/tree/datum.go:6644–6670

DatumNext returns a datum that is "next" to the given one. For many types it just delegates to Datum.Next, but for some types that don't have an implementation of that function this method makes the best effort to come up with a reasonable next datum that is greater than the given one. The return v

(
	ctx context.Context, datum Datum, cmpCtx CompareContext, collationEnv *CollationEnvironment,
)

// The return value is undefined if Datum.IsMax returns true or if the value is
// NaN or an infinity (for floats and decimals).
func DatumNext(
	ctx context.Context, datum Datum, cmpCtx CompareContext, collationEnv *CollationEnvironment,
) (Datum, bool) {
	datum = UnwrapDOidWrapper(datum)
	switch d := datum.(type) {
	case *DDecimal:
		var next DDecimal
		var add apd.Decimal
		_, err := add.SetFloat64(1e-6)
		if err != nil {
			return nil, false
		}
		_, err = ExactCtx.Add(&next.Decimal, &d.Decimal, &add)
		if err != nil {
			return nil, false
		}
		return &next, true
	case *DInterval:
		next := d.Add(duration.MakeDuration(1000000 /* nanos */, 0 /* days */, 0 /* months */))
		return NewDInterval(next, types.DefaultIntervalTypeMetadata), true
	default:
		// TODO(yuzefovich): consider adding support for other datums that don't
		// have Datum.Next implementation (DCollatedString, DGeography,
		// DGeometry, DBox2D, DJSON).
		return datum.Next(ctx, cmpCtx)
	}
}