add vendor data

vendor/github.com/dunglas/httpsfv/integer.go

@@ -0,0 +1,120 @@
+package httpsfv
+
+import (
+	"errors"
+	"io"
+	"strconv"
+)
+
+const maxDigit = 12
+
+// ErrNotDigit is returned when a character should be a digit but isn't.
+var ErrNotDigit = errors.New("character is not a digit")
+
+// ErrNumberOutOfRange is returned when the number is too large according to the specification.
+var ErrNumberOutOfRange = errors.New("integer or decimal out of range")
+
+// ErrInvalidDecimalFormat is returned when the decimal format is invalid.
+var ErrInvalidDecimalFormat = errors.New("invalid decimal format")
+
+const (
+	typeInteger = iota
+	typeDecimal
+)
+
+// marshalInteger serializes as defined in
+// https://httpwg.org/specs/rfc9651.html#integer.
+func marshalInteger(b io.StringWriter, i int64) error {
+	if i < -999999999999999 || i > 999999999999999 {
+		return ErrNumberOutOfRange
+	}
+
+	_, err := b.WriteString(strconv.FormatInt(i, 10))
+
+	return err
+}
+
+// parseNumber parses as defined in
+// https://httpwg.org/specs/rfc9651.html#parse-number.
+func parseNumber(s *scanner) (interface{}, error) {
+	neg := isNeg(s)
+	if neg && s.eof() {
+		return 0, &UnmarshalError{s.off, ErrUnexpectedEndOfString}
+	}
+
+	if !isDigit(s.data[s.off]) {
+		return 0, &UnmarshalError{s.off, ErrNotDigit}
+	}
+
+	start := s.off
+	s.off++
+
+	var (
+		decSepOff int
+		t         = typeInteger
+	)
+
+	for s.off < len(s.data) {
+		size := s.off - start
+		if (t == typeInteger && (size >= 15)) || size >= 16 {
+			return 0, &UnmarshalError{s.off, ErrNumberOutOfRange}
+		}
+
+		c := s.data[s.off]
+		if isDigit(c) {
+			s.off++
+
+			continue
+		}
+
+		if t == typeInteger && c == '.' {
+			if size > maxDigit {
+				return 0, &UnmarshalError{s.off, ErrNumberOutOfRange}
+			}
+
+			t = typeDecimal
+			decSepOff = s.off
+			s.off++
+
+			continue
+		}
+
+		break
+	}
+
+	str := s.data[start:s.off]
+
+	if t == typeInteger {
+		return parseInteger(str, neg, s.off)
+	}
+
+	return parseDecimal(s, decSepOff, str, neg)
+}
+
+func isNeg(s *scanner) bool {
+	if s.data[s.off] == '-' {
+		s.off++
+
+		return true
+	}
+
+	return false
+}
+
+func parseInteger(str string, neg bool, off int) (int64, error) {
+	i, err := strconv.ParseInt(str, 10, 64)
+	if err != nil {
+		// Should never happen
+		return 0, &UnmarshalError{off, err}
+	}
+
+	if neg {
+		i = -i
+	}
+
+	if i < -999999999999999 || i > 999999999999999 {
+		return 0, &UnmarshalError{off, ErrNumberOutOfRange}
+	}
+
+	return i, err
+}