Function prettyPrintFirstValue

pkg/util/encoding/encoding.go:1507–1653

prettyPrintFirstValue returns a string representation of the first decodable value in the provided byte slice, along with the remaining byte slice after decoding. Ascending will be the default direction (when dir is the 0 value) for all values except for NotNull. NotNull: if Ascending or Descendin

(dir Direction, b []byte)

// are always encoded Ascending), this will always print out the correct key
// even if we don't have directions for the child index's columns.
func prettyPrintFirstValue(dir Direction, b []byte) ([]byte, string, error) {
	var err error
	switch PeekType(b) {
	case Null:
		b, _ = DecodeIfNull(b)
		return b, "NULL", nil
	case True:
		return b[1:], "True", nil
	case False:
		return b[1:], "False", nil
	case Array:
		return b[1:], "Arr", nil
	case NotNull:
		// The tag can be either encodedNotNull or encodedNotNullDesc. The
		// latter can be an interleaved sentinel.
		isNotNullDesc := (b[0] == encodedNotNullDesc)
		b, _ = DecodeIfNotNull(b)
		if dir != Ascending && dir != Descending && isNotNullDesc {
			// Unspecified direction (0 value) will default to '#' for the
			// interleaved sentinel.
			return b, "#", nil
		}
		return b, "!NULL", nil
	case Int:
		var i int64
		if dir == Descending {
			b, i, err = DecodeVarintDescending(b)
		} else {
			b, i, err = DecodeVarintAscending(b)
		}
		if err != nil {
			return b, "", err
		}
		return b, strconv.FormatInt(i, 10), nil
	case Float:
		var f float64
		if dir == Descending {
			b, f, err = DecodeFloatDescending(b)
		} else {
			b, f, err = DecodeFloatAscending(b)
		}
		if err != nil {
			return b, "", err
		}
		return b, strconv.FormatFloat(f, 'g', -1, 64), nil
	case Decimal:
		var d apd.Decimal
		if dir == Descending {
			b, d, err = DecodeDecimalDescending(b, nil)
		} else {
			b, d, err = DecodeDecimalAscending(b, nil)
		}
		if err != nil {
			return b, "", err
		}
		return b, d.String(), nil
	case BitArray:
		if dir == Descending {