helper.go

package strftime

func appendInt(b []byte, x int, width int) []byte {
	u := uint(x)
	if x < 0 {
		b = append(b, '-')
		u = uint(-x)
	}

	// Assemble decimal in reverse order.
	var buf [20]byte
	i := len(buf)
	for u >= 10 {
		i--
		q := u / 10
		buf[i] = byte('0' + u - q*10)
		u = q
	}
	i--
	buf[i] = byte('0' + u)

	// Add 0-padding.
	for w := len(buf) - i; w < width; w++ {
		b = append(b, '0')
	}

	return append(b, buf[i:]...)
}

func appendInt64(b []byte, x int64, width int) []byte {
	u := uint64(x)
	if x < 0 {
		b = append(b, '-')
		u = uint64(-x)
	}

	// Assemble decimal in reverse order.
	var buf [20]byte
	i := len(buf)
	for u >= 10 {
		i--
		q := u / 10
		buf[i] = byte('0' + u - q*10)
		u = q
	}
	i--
	buf[i] = byte('0' + u)

	// Add 0-padding.
	for w := len(buf) - i; w < width; w++ {
		b = append(b, '0')
	}

	return append(b, buf[i:]...)
}

func appendUint8(b []byte, u uint8, width int) []byte {
	// Assemble decimal in reverse order.
	var buf [3]byte
	i := len(buf)
	for u >= 10 {
		i--
		q := u / 10
		buf[i] = byte('0' + u - q*10)
		u = q
	}
	i--
	buf[i] = byte('0' + u)

	// Add 0-padding.
	for w := len(buf) - i; w < width; w++ {
		b = append(b, '0')
	}

	return append(b, buf[i:]...)
}

func appendUint8Sp(b []byte, u uint8, width int) []byte {
	// Assemble decimal in reverse order.
	var buf [3]byte
	i := len(buf)
	for u >= 10 {
		i--
		q := u / 10
		buf[i] = byte('0' + u - q*10)
		u = q
	}
	i--
	buf[i] = byte('0' + u)

	// Add space-padding.
	for w := len(buf) - i; w < width; w++ {
		b = append(b, ' ')
	}

	return append(b, buf[i:]...)
}