Function PerformCast

pkg/sql/sem/tree/eval.go:3297–3925

PerformCast performs a cast from the provided Datum to the specified types.T.

(ctx *EvalContext, d Datum, t *types.T)

// PerformCast performs a cast from the provided Datum to the specified
// types.T.
func PerformCast(ctx *EvalContext, d Datum, t *types.T) (Datum, error) {
	switch t.Family() {
	case types.BitFamily:
		switch v := d.(type) {
		case *DBitArray:
			if t.Width() == 0 || v.BitLen() == uint(t.Width()) {
				return d, nil
			}
			var a DBitArray
			switch t.Oid() {
			case oid.T_varbit:
				// VARBITs do not have padding attached.
				a.BitArray = v.BitArray.Clone()
				if uint(t.Width()) < a.BitArray.BitLen() {
					a.BitArray = a.BitArray.ToWidth(uint(t.Width()))
				}
			default:
				a.BitArray = v.BitArray.Clone().ToWidth(uint(t.Width()))
			}
			return &a, nil
		case *DInt:
			return NewDBitArrayFromInt(int64(*v), uint(t.Width()))
		case *DString:
			res, err := bitarray.Parse(string(*v))
			if err != nil {
				return nil, err
			}
			if t.Width() > 0 {
				res = res.ToWidth(uint(t.Width()))
			}
			return &DBitArray{BitArray: res}, nil
		case *DCollatedString:
			res, err := bitarray.Parse(v.Contents)
			if err != nil {
				return nil, err
			}
			if t.Width() > 0 {
				res = res.ToWidth(uint(t.Width()))
			}
			return &DBitArray{BitArray: res}, nil
		}

	case types.BoolFamily:
		switch v := d.(type) {
		case *DBool:
			return d, nil
		case *DInt:
			return MakeDBool(*v != 0), nil
		case *DFloat:
			return MakeDBool(*v != 0), nil
		case *DDecimal:
			return MakeDBool(v.Sign() != 0), nil
		case *DString:
			return ParseDBool(string(*v))
		case *DCollatedString:
			return ParseDBool(v.Contents)
		}