Method parseNumber

json/parse.go:288–386

(b []byte)

}

func (d decoder) parseNumber(b []byte) (v, r []byte, kind Kind, err error) {
	if len(b) == 0 {
		r, err = b, unexpectedEOF(b)
		return
	}

	// Assume it's an unsigned integer at first.
	kind = Uint

	i := 0
	// sign
	if b[i] == '-' {
		kind = Int
		i++
	}

	if i == len(b) {
		r, err = b[i:], syntaxError(b, "missing number value after sign")
		return
	}

	if b[i] < '0' || b[i] > '9' {
		r, err = b[i:], syntaxError(b, "expected digit but got '%c'", b[i])
		return
	}

	// integer part
	if b[i] == '0' {
		i++
		if i == len(b) || (b[i] != '.' && b[i] != 'e' && b[i] != 'E') {
			v, r = b[:i], b[i:]
			return
		}
		if '0' <= b[i] && b[i] <= '9' {
			r, err = b[i:], syntaxError(b, "cannot decode number with leading '0' character")
			return
		}
	}

	for i < len(b) && '0' <= b[i] && b[i] <= '9' {
		i++
	}

	// decimal part
	if i < len(b) && b[i] == '.' {
		kind = Float
		i++
		decimalStart := i

		for i < len(b) {
			if c := b[i]; '0' > c || c > '9' {
				if i == decimalStart {
					r, err = b[i:], syntaxError(b, "expected digit but found '%c'", c)
					return
				}
				break
			}
			i++