func FromSubstraitType()

in arrow/compute/exprs/types.go [703:803]
96 lines of code
33 McCabe index (conditional complexity)

func FromSubstraitType(t types.Type, ext ExtensionIDSet) (arrow.DataType, bool, error) {
	nullable := IsNullable(t)

	if t.GetTypeVariationReference() > 0 {
		_, dt, ok := ext.DecodeTypeArrow(t.GetTypeVariationReference())
		if ok {
			return dt, nullable, nil
		}
	}

	switch t := t.(type) {
	case *types.BooleanType:
		return arrow.FixedWidthTypes.Boolean, nullable, nil
	case *types.Int8Type:
		return arrow.PrimitiveTypes.Int8, nullable, nil
	case *types.Int16Type:
		return arrow.PrimitiveTypes.Int16, nullable, nil
	case *types.Int32Type:
		return arrow.PrimitiveTypes.Int32, nullable, nil
	case *types.Int64Type:
		return arrow.PrimitiveTypes.Int64, nullable, nil
	case *types.Float32Type:
		return arrow.PrimitiveTypes.Float32, nullable, nil
	case *types.Float64Type:
		return arrow.PrimitiveTypes.Float64, nullable, nil
	case *types.StringType:
		return arrow.BinaryTypes.String, nullable, nil
	case *types.BinaryType:
		return arrow.BinaryTypes.Binary, nullable, nil
	case *types.TimestampType:
		return &arrow.TimestampType{Unit: arrow.Microsecond}, nullable, nil
	case *types.TimestampTzType:
		return &arrow.TimestampType{Unit: arrow.Microsecond, TimeZone: TimestampTzTimezone},
			nullable, nil
	case *types.DateType:
		return arrow.FixedWidthTypes.Date32, nullable, nil
	case *types.TimeType:
		return &arrow.Time64Type{Unit: arrow.Microsecond}, nullable, nil
	case *types.IntervalYearType:
		return intervalYear(), nullable, nil
	case *types.IntervalDayType:
		return intervalDay(), nullable, nil
	case *types.UUIDType:
		return uuid(), nullable, nil
	case *types.FixedCharType:
		return fixedChar(t.Length), nullable, nil
	case *types.VarCharType:
		return varChar(t.Length), nullable, nil
	case *types.FixedBinaryType:
		return &arrow.FixedSizeBinaryType{ByteWidth: int(t.Length)}, nullable, nil
	case *types.DecimalType:
		return &arrow.Decimal128Type{
			Precision: t.Precision,
			Scale:     t.Scale,
		}, nullable, nil
	case *types.StructType:
		i := 0
		fields, err := FieldsFromSubstrait(t.Types, func() string {
			i++
			return strconv.Itoa(i)
		}, ext)
		if err != nil {
			return nil, false, err
		}

		return arrow.StructOf(fields...), nullable, nil
	case *types.ListType:
		elem, elemNullable, err := FromSubstraitType(t.Type, ext)
		if err != nil {
			return nil, false, err
		}
		return arrow.ListOfField(arrow.Field{Name: "item", Type: elem, Nullable: elemNullable}),
			nullable, nil
	case *types.MapType:
		key, keyNullable, err := FromSubstraitType(t.Key, ext)
		if err != nil {
			return nil, false, err
		}
		if keyNullable {
			return nil, false, fmt.Errorf("%w: encountered nullable key field when converting to arrow.Map",
				arrow.ErrInvalid)
		}

		value, valueNullable, err := FromSubstraitType(t.Value, ext)
		if err != nil {
			return nil, false, err
		}
		ret := arrow.MapOf(key, value)
		ret.SetItemNullable(valueNullable)
		return ret, nullable, nil
	case *types.UserDefinedType:
		anchor := t.TypeReference
		_, dt, ok := ext.DecodeTypeArrow(anchor)
		if !ok {
			return nil, false, arrow.ErrNotImplemented
		}
		return dt, nullable, nil
	}

	return nil, false, arrow.ErrNotImplemented
}