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Diffstat (limited to 'csharp/src/ProtocolBuffers/TextTokenizer.cs')
| -rw-r--r-- | csharp/src/ProtocolBuffers/TextTokenizer.cs | 501 |
1 files changed, 501 insertions, 0 deletions
diff --git a/csharp/src/ProtocolBuffers/TextTokenizer.cs b/csharp/src/ProtocolBuffers/TextTokenizer.cs new file mode 100644 index 00000000..5bb27fd0 --- /dev/null +++ b/csharp/src/ProtocolBuffers/TextTokenizer.cs @@ -0,0 +1,501 @@ +#region Copyright notice and license
+
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc. All rights reserved.
+// http://github.com/jskeet/dotnet-protobufs/
+// Original C++/Java/Python code:
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#endregion
+
+using System;
+using System.Globalization;
+using System.Text.RegularExpressions;
+
+namespace Google.ProtocolBuffers
+{
+ /// <summary>
+ /// Represents a stream of tokens parsed from a string.
+ /// </summary>
+ internal sealed class TextTokenizer
+ {
+ private readonly string text;
+ private string currentToken;
+
+ /// <summary>
+ /// The character index within the text to perform the next regex match at.
+ /// </summary>
+ private int matchPos = 0;
+
+ /// <summary>
+ /// The character index within the text at which the current token begins.
+ /// </summary>
+ private int pos = 0;
+
+ /// <summary>
+ /// The line number of the current token.
+ /// </summary>
+ private int line = 0;
+
+ /// <summary>
+ /// The column number of the current token.
+ /// </summary>
+ private int column = 0;
+
+ /// <summary>
+ /// The line number of the previous token.
+ /// </summary>
+ private int previousLine = 0;
+
+ /// <summary>
+ /// The column number of the previous token.
+ /// </summary>
+ private int previousColumn = 0;
+
+ // Note: atomic groups used to mimic possessive quantifiers in Java in both of these regexes
+ internal static readonly Regex WhitespaceAndCommentPattern = new Regex("\\G(?>(\\s|(#.*$))+)",
+ FrameworkPortability.
+ CompiledRegexWhereAvailable |
+ RegexOptions.Multiline);
+
+ private static readonly Regex TokenPattern = new Regex(
+ "\\G[a-zA-Z_](?>[0-9a-zA-Z_+-]*)|" + // an identifier
+ "\\G[0-9+-](?>[0-9a-zA-Z_.+-]*)|" + // a number
+ "\\G\"(?>([^\"\\\n\\\\]|\\\\.)*)(\"|\\\\?$)|" + // a double-quoted string
+ "\\G\'(?>([^\"\\\n\\\\]|\\\\.)*)(\'|\\\\?$)", // a single-quoted string
+ FrameworkPortability.CompiledRegexWhereAvailable | RegexOptions.Multiline);
+
+ private static readonly Regex DoubleInfinity = new Regex("^-?inf(inity)?$",
+ FrameworkPortability.CompiledRegexWhereAvailable |
+ RegexOptions.IgnoreCase);
+
+ private static readonly Regex FloatInfinity = new Regex("^-?inf(inity)?f?$",
+ FrameworkPortability.CompiledRegexWhereAvailable |
+ RegexOptions.IgnoreCase);
+
+ private static readonly Regex FloatNan = new Regex("^nanf?$",
+ FrameworkPortability.CompiledRegexWhereAvailable |
+ RegexOptions.IgnoreCase);
+
+ /** Construct a tokenizer that parses tokens from the given text. */
+
+ public TextTokenizer(string text)
+ {
+ this.text = text;
+ SkipWhitespace();
+ NextToken();
+ }
+
+ /// <summary>
+ /// Are we at the end of the input?
+ /// </summary>
+ public bool AtEnd
+ {
+ get { return currentToken.Length == 0; }
+ }
+
+ /// <summary>
+ /// Advances to the next token.
+ /// </summary>
+ public void NextToken()
+ {
+ previousLine = line;
+ previousColumn = column;
+
+ // Advance the line counter to the current position.
+ while (pos < matchPos)
+ {
+ if (text[pos] == '\n')
+ {
+ ++line;
+ column = 0;
+ }
+ else
+ {
+ ++column;
+ }
+ ++pos;
+ }
+
+ // Match the next token.
+ if (matchPos == text.Length)
+ {
+ // EOF
+ currentToken = "";
+ }
+ else
+ {
+ Match match = TokenPattern.Match(text, matchPos);
+ if (match.Success)
+ {
+ currentToken = match.Value;
+ matchPos += match.Length;
+ }
+ else
+ {
+ // Take one character.
+ currentToken = text[matchPos].ToString();
+ matchPos++;
+ }
+
+ SkipWhitespace();
+ }
+ }
+
+ /// <summary>
+ /// Skip over any whitespace so that matchPos starts at the next token.
+ /// </summary>
+ private void SkipWhitespace()
+ {
+ Match match = WhitespaceAndCommentPattern.Match(text, matchPos);
+ if (match.Success)
+ {
+ matchPos += match.Length;
+ }
+ }
+
+ /// <summary>
+ /// If the next token exactly matches the given token, consume it and return
+ /// true. Otherwise, return false without doing anything.
+ /// </summary>
+ public bool TryConsume(string token)
+ {
+ if (currentToken == token)
+ {
+ NextToken();
+ return true;
+ }
+ return false;
+ }
+
+ /*
+ * If the next token exactly matches {@code token}, consume it. Otherwise,
+ * throw a {@link ParseException}.
+ */
+
+ /// <summary>
+ /// If the next token exactly matches the specified one, consume it.
+ /// Otherwise, throw a FormatException.
+ /// </summary>
+ /// <param name="token"></param>
+ public void Consume(string token)
+ {
+ if (!TryConsume(token))
+ {
+ throw CreateFormatException("Expected \"" + token + "\".");
+ }
+ }
+
+ /// <summary>
+ /// Returns true if the next token is an integer, but does not consume it.
+ /// </summary>
+ public bool LookingAtInteger()
+ {
+ if (currentToken.Length == 0)
+ {
+ return false;
+ }
+
+ char c = currentToken[0];
+ return ('0' <= c && c <= '9') || c == '-' || c == '+';
+ }
+
+ /// <summary>
+ /// If the next token is an identifier, consume it and return its value.
+ /// Otherwise, throw a FormatException.
+ /// </summary>
+ public string ConsumeIdentifier()
+ {
+ foreach (char c in currentToken)
+ {
+ if (('a' <= c && c <= 'z') ||
+ ('A' <= c && c <= 'Z') ||
+ ('0' <= c && c <= '9') ||
+ (c == '_') || (c == '.'))
+ {
+ // OK
+ }
+ else
+ {
+ throw CreateFormatException("Expected identifier.");
+ }
+ }
+
+ string result = currentToken;
+ NextToken();
+ return result;
+ }
+
+ /// <summary>
+ /// If the next token is a 32-bit signed integer, consume it and return its
+ /// value. Otherwise, throw a FormatException.
+ /// </summary>
+ public int ConsumeInt32()
+ {
+ try
+ {
+ int result = TextFormat.ParseInt32(currentToken);
+ NextToken();
+ return result;
+ }
+ catch (FormatException e)
+ {
+ throw CreateIntegerParseException(e);
+ }
+ }
+
+ /// <summary>
+ /// If the next token is a 32-bit unsigned integer, consume it and return its
+ /// value. Otherwise, throw a FormatException.
+ /// </summary>
+ public uint ConsumeUInt32()
+ {
+ try
+ {
+ uint result = TextFormat.ParseUInt32(currentToken);
+ NextToken();
+ return result;
+ }
+ catch (FormatException e)
+ {
+ throw CreateIntegerParseException(e);
+ }
+ }
+
+ /// <summary>
+ /// If the next token is a 64-bit signed integer, consume it and return its
+ /// value. Otherwise, throw a FormatException.
+ /// </summary>
+ public long ConsumeInt64()
+ {
+ try
+ {
+ long result = TextFormat.ParseInt64(currentToken);
+ NextToken();
+ return result;
+ }
+ catch (FormatException e)
+ {
+ throw CreateIntegerParseException(e);
+ }
+ }
+
+ /// <summary>
+ /// If the next token is a 64-bit unsigned integer, consume it and return its
+ /// value. Otherwise, throw a FormatException.
+ /// </summary>
+ public ulong ConsumeUInt64()
+ {
+ try
+ {
+ ulong result = TextFormat.ParseUInt64(currentToken);
+ NextToken();
+ return result;
+ }
+ catch (FormatException e)
+ {
+ throw CreateIntegerParseException(e);
+ }
+ }
+
+ /// <summary>
+ /// If the next token is a double, consume it and return its value.
+ /// Otherwise, throw a FormatException.
+ /// </summary>
+ public double ConsumeDouble()
+ {
+ // We need to parse infinity and nan separately because
+ // double.Parse() does not accept "inf", "infinity", or "nan".
+ if (DoubleInfinity.IsMatch(currentToken))
+ {
+ bool negative = currentToken.StartsWith("-");
+ NextToken();
+ return negative ? double.NegativeInfinity : double.PositiveInfinity;
+ }
+ if (currentToken.Equals("nan", StringComparison.OrdinalIgnoreCase))
+ {
+ NextToken();
+ return Double.NaN;
+ }
+
+ try
+ {
+ double result = double.Parse(currentToken, FrameworkPortability.InvariantCulture);
+ NextToken();
+ return result;
+ }
+ catch (FormatException e)
+ {
+ throw CreateFloatParseException(e);
+ }
+ catch (OverflowException e)
+ {
+ throw CreateFloatParseException(e);
+ }
+ }
+
+ /// <summary>
+ /// If the next token is a float, consume it and return its value.
+ /// Otherwise, throw a FormatException.
+ /// </summary>
+ public float ConsumeFloat()
+ {
+ // We need to parse infinity and nan separately because
+ // Float.parseFloat() does not accept "inf", "infinity", or "nan".
+ if (FloatInfinity.IsMatch(currentToken))
+ {
+ bool negative = currentToken.StartsWith("-");
+ NextToken();
+ return negative ? float.NegativeInfinity : float.PositiveInfinity;
+ }
+ if (FloatNan.IsMatch(currentToken))
+ {
+ NextToken();
+ return float.NaN;
+ }
+
+ if (currentToken.EndsWith("f"))
+ {
+ currentToken = currentToken.TrimEnd('f');
+ }
+
+ try
+ {
+ float result = float.Parse(currentToken, FrameworkPortability.InvariantCulture);
+ NextToken();
+ return result;
+ }
+ catch (FormatException e)
+ {
+ throw CreateFloatParseException(e);
+ }
+ catch (OverflowException e)
+ {
+ throw CreateFloatParseException(e);
+ }
+ }
+
+ /// <summary>
+ /// If the next token is a Boolean, consume it and return its value.
+ /// Otherwise, throw a FormatException.
+ /// </summary>
+ public bool ConsumeBoolean()
+ {
+ if (currentToken == "true")
+ {
+ NextToken();
+ return true;
+ }
+ if (currentToken == "false")
+ {
+ NextToken();
+ return false;
+ }
+ throw CreateFormatException("Expected \"true\" or \"false\".");
+ }
+
+ /// <summary>
+ /// If the next token is a string, consume it and return its (unescaped) value.
+ /// Otherwise, throw a FormatException.
+ /// </summary>
+ public string ConsumeString()
+ {
+ return ConsumeByteString().ToStringUtf8();
+ }
+
+ /// <summary>
+ /// If the next token is a string, consume it, unescape it as a
+ /// ByteString and return it. Otherwise, throw a FormatException.
+ /// </summary>
+ public ByteString ConsumeByteString()
+ {
+ char quote = currentToken.Length > 0 ? currentToken[0] : '\0';
+ if (quote != '\"' && quote != '\'')
+ {
+ throw CreateFormatException("Expected string.");
+ }
+
+ if (currentToken.Length < 2 ||
+ currentToken[currentToken.Length - 1] != quote)
+ {
+ throw CreateFormatException("String missing ending quote.");
+ }
+
+ try
+ {
+ string escaped = currentToken.Substring(1, currentToken.Length - 2);
+ ByteString result = TextFormat.UnescapeBytes(escaped);
+ NextToken();
+ return result;
+ }
+ catch (FormatException e)
+ {
+ throw CreateFormatException(e.Message);
+ }
+ }
+
+ /// <summary>
+ /// Returns a format exception with the current line and column numbers
+ /// in the description, suitable for throwing.
+ /// </summary>
+ public FormatException CreateFormatException(string description)
+ {
+ // Note: People generally prefer one-based line and column numbers.
+ return new FormatException((line + 1) + ":" + (column + 1) + ": " + description);
+ }
+
+ /// <summary>
+ /// Returns a format exception with the line and column numbers of the
+ /// previous token in the description, suitable for throwing.
+ /// </summary>
+ public FormatException CreateFormatExceptionPreviousToken(string description)
+ {
+ // Note: People generally prefer one-based line and column numbers.
+ return new FormatException((previousLine + 1) + ":" + (previousColumn + 1) + ": " + description);
+ }
+
+ /// <summary>
+ /// Constructs an appropriate FormatException for the given existing exception
+ /// when trying to parse an integer.
+ /// </summary>
+ private FormatException CreateIntegerParseException(FormatException e)
+ {
+ return CreateFormatException("Couldn't parse integer: " + e.Message);
+ }
+
+ /// <summary>
+ /// Constructs an appropriate FormatException for the given existing exception
+ /// when trying to parse a float or double.
+ /// </summary>
+ private FormatException CreateFloatParseException(Exception e)
+ {
+ return CreateFormatException("Couldn't parse number: " + e.Message);
+ }
+ }
+}
\ No newline at end of file |