Function atou

stack/context.go:1162–1174

atou is a fast Atoi() function. It is a very simplified version of strconv.Atoi() that it never go into the slow path and it operates on []byte instead of string so it doesn't do memory allocation. It will fail on edge cases like prefix of zeros and other things that the panic stack trace generator

(s []byte)

//
// It doesn't handle negative values.
func atou(s []byte) (int, bool) {
	if l := len(s); strconv.IntSize == 32 && (0 < l && l < 10) || strconv.IntSize == 64 && (0 < l && l < 19) {
		n := 0
		for _, ch := range s {
			if ch -= '0'; ch > 9 {
				return 0, false
			}
			n = n*10 + int(ch)
		}
		return n, true
	}
	return 0, false
}

// trimLeftSpace is the faster equivalent of bytes.TrimLeft(s, "\t ").
func trimLeftSpace(s []byte) []byte {