kubernetes/vendor/google.golang.org/protobuf/internal/encoding/json/decode_number.go

// parseNumber reads the given []byte for a valid JSON number. If it is valid,
// it returns the number of bytes.  Parsing logic follows the definition in
// https://tools.ietf.org/html/rfc7159#section-6, and is based off
// encoding/json.isValidNumber function.
func parseNumber(input []byte) (int, bool) { … }

type numberParts …

// parseNumber constructs numberParts from given []byte. The logic here is
// similar to consumeNumber above with the difference of having to construct
// numberParts. The slice fields in numberParts are subslices of the input.
func parseNumberParts(input []byte) (numberParts, bool) { … }

// normalizeToIntString returns an integer string in normal form without the
// E-notation for given numberParts. It will return false if it is not an
// integer or if the exponent exceeds than max/min int value.
func normalizeToIntString(n numberParts) (string, bool) { … }