Exemplo n.º 1
0
        public static bool TryParse(ReadOnlySpan <byte> source, out short value, out int bytesConsumed, char standardFormat = default)
        {
            switch (standardFormat)
            {
            case default(char):
            case 'g':
            case 'G':
            case 'd':
            case 'D':
                return(TryParseInt16D(source, out value, out bytesConsumed));

            case 'n':
            case 'N':
                return(TryParseInt16N(source, out value, out bytesConsumed));

            case 'x':
            case 'X':
                value = default;
                return(TryParseUInt16X(source, out Unsafe.As <short, ushort>(ref value), out bytesConsumed));

            default:
                return(ParserHelpers.TryParseThrowFormatException(out value, out bytesConsumed));
            }
        }
Exemplo n.º 2
0
        /// <summary>
        /// Parses a DateTime at the start of a Utf8 string.
        /// </summary>
        /// <param name="source">The Utf8 string to parse</param>
        /// <param name="value">Receives the parsed value</param>
        /// <param name="bytesConsumed">On a successful parse, receives the length in bytes of the substring that was parsed </param>
        /// <param name="standardFormat">Expected format of the Utf8 string</param>
        /// <returns>
        /// true for success. "bytesConsumed" contains the length in bytes of the substring that was parsed.
        /// false if the string was not syntactically valid or an overflow or underflow occurred. "bytesConsumed" is set to 0.
        /// </returns>
        /// <remarks>
        /// Formats supported:
        ///     default       05/25/2017 10:30:15 -08:00
        ///     G             05/25/2017 10:30:15
        ///     R             Tue, 03 Jan 2017 08:08:05 GMT       (RFC 1123)
        ///     l             tue, 03 jan 2017 08:08:05 gmt       (Lowercase RFC 1123)
        ///     O             2017-06-12T05:30:45.7680000-07:00   (Round-trippable)
        /// </remarks>
        /// <exceptions>
        /// <cref>System.FormatException</cref> if the format is not valid for this data type.
        /// </exceptions>
        public static bool TryParse(ReadOnlySpan <byte> source, out DateTime value, out int bytesConsumed, char standardFormat = default)
        {
            switch (standardFormat)
            {
            case 'R':
            {
                if (!TryParseDateTimeOffsetR(source, NoFlipCase, out DateTimeOffset dateTimeOffset, out bytesConsumed))
                {
                    value = default;
                    return(false);
                }
                value = dateTimeOffset.DateTime;          // (returns a DateTimeKind.Unspecified to match DateTime.ParseExact(). Maybe better to return UtcDateTime instead?)
                return(true);
            }

            case 'l':
            {
                if (!TryParseDateTimeOffsetR(source, FlipCase, out DateTimeOffset dateTimeOffset, out bytesConsumed))
                {
                    value = default;
                    return(false);
                }
                value = dateTimeOffset.DateTime;          // (returns a DateTimeKind.Unspecified to match DateTime.ParseExact(). Maybe better to return UtcDateTime instead?)
                return(true);
            }

            case 'O':
            {
                // Emulates DateTime.ParseExact(text, "O", CultureInfo.InvariantCulture, DateTimeStyles.RoundtripKind)
                // In particular, the formatted string "encodes" the DateTimeKind according to the following table:
                //
                //         2017-06-12T05:30:45.7680000       - Unspecified
                //         2017-06-12T05:30:45.7680000+00:00 - Local
                //         2017-06-12T05:30:45.7680000Z      - Utc

                if (!TryParseDateTimeOffsetO(source, out DateTimeOffset dateTimeOffset, out bytesConsumed, out DateTimeKind kind))
                {
                    value         = default;
                    bytesConsumed = 0;
                    return(false);
                }

                switch (kind)
                {
                case DateTimeKind.Local:
                    value = dateTimeOffset.LocalDateTime;
                    break;

                case DateTimeKind.Utc:
                    value = dateTimeOffset.UtcDateTime;
                    break;

                default:
                    Debug.Assert(kind == DateTimeKind.Unspecified);
                    value = dateTimeOffset.DateTime;
                    break;
                }

                return(true);
            }

            case default(char):
            case 'G':
                return(TryParseDateTimeG(source, out value, out _, out bytesConsumed));

            default:
                return(ParserHelpers.TryParseThrowFormatException(out value, out bytesConsumed));
            }
        }