go/src/pkg/strconv/itoa.go

// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package strconv

// FormatUint returns the string representation of i in the given base.
func FormatUint(i uint64, base int) string {
	u := i
	if base < 2 || 36 < base {
		panic("invalid base " + Itoa(base))
	}
	if u == 0 {
		return "0"
	}

	// Assemble decimal in reverse order.
	var buf [64]byte
	j := len(buf)
	b := uint64(base)
	for u > 0 {
		j--
		buf[j] = "0123456789abcdefghijklmnopqrstuvwxyz"[u%b]
		u /= b
	}

	return string(buf[j:])
}

// FormatInt returns the string representation of i in the given base.
func FormatInt(i int64, base int) string {
	if i == 0 {
		return "0"
	}

	if i < 0 {
		return "-" + FormatUint(-uint64(i), base)
	}
	return FormatUint(uint64(i), base)
}

// Itoa is shorthand for FormatInt(i, 10).
func Itoa(i int) string {
	return FormatInt(int64(i), 10)
}

// AppendInt appends the string form of the integer i,
// as generated by FormatInt, to dst and returns the extended buffer.
func AppendInt(dst []byte, i int64, base int) []byte {
	return append(dst, FormatInt(i, base)...)
}

// AppendUint appends the string form of the unsigned integer i,
// as generated by FormatUint, to dst and returns the extended buffer.
func AppendUint(dst []byte, i uint64, base int) []byte {
	return append(dst, FormatUint(i, base)...)
}