diff options
Diffstat (limited to 'src/ProtocolBuffers/TextTokenizer.cs')
-rw-r--r-- | src/ProtocolBuffers/TextTokenizer.cs | 824 |
1 files changed, 412 insertions, 412 deletions
diff --git a/src/ProtocolBuffers/TextTokenizer.cs b/src/ProtocolBuffers/TextTokenizer.cs index ce067728..d3e8878c 100644 --- a/src/ProtocolBuffers/TextTokenizer.cs +++ b/src/ProtocolBuffers/TextTokenizer.cs @@ -1,412 +1,412 @@ -#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|(#.*$))+)", - SilverlightCompatibility.CompiledRegexWhereAvailable | RegexOptions.Multiline); - private static readonly Regex TokenPattern = new Regex( - "\\G[a-zA-Z_](?>[0-9a-zA-Z_+-]*)|" + // an identifier - "\\G[0-9+-](?>[0-9a-zA-Z_.+-]*)|" + // a number - "\\G\"(?>([^\"\\\n\\\\]|\\\\.)*)(\"|\\\\?$)|" + // a double-quoted string - "\\G\'(?>([^\"\\\n\\\\]|\\\\.)*)(\'|\\\\?$)", // a single-quoted string - SilverlightCompatibility.CompiledRegexWhereAvailable | RegexOptions.Multiline); - - private static readonly Regex DoubleInfinity = new Regex("^-?inf(inity)?$", - SilverlightCompatibility.CompiledRegexWhereAvailable | RegexOptions.IgnoreCase); - private static readonly Regex FloatInfinity = new Regex("^-?inf(inity)?f?$", - SilverlightCompatibility.CompiledRegexWhereAvailable | RegexOptions.IgnoreCase); - private static readonly Regex FloatNan = new Regex("^nanf?$", - SilverlightCompatibility.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.InvariantCultureIgnoreCase)) { - NextToken(); - return Double.NaN; - } - - try { - double result = double.Parse(currentToken, CultureInfo.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, CultureInfo.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); - } - } -} +#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|(#.*$))+)",
+ SilverlightCompatibility.CompiledRegexWhereAvailable | RegexOptions.Multiline);
+ private static readonly Regex TokenPattern = new Regex(
+ "\\G[a-zA-Z_](?>[0-9a-zA-Z_+-]*)|" + // an identifier
+ "\\G[0-9+-](?>[0-9a-zA-Z_.+-]*)|" + // a number
+ "\\G\"(?>([^\"\\\n\\\\]|\\\\.)*)(\"|\\\\?$)|" + // a double-quoted string
+ "\\G\'(?>([^\"\\\n\\\\]|\\\\.)*)(\'|\\\\?$)", // a single-quoted string
+ SilverlightCompatibility.CompiledRegexWhereAvailable | RegexOptions.Multiline);
+
+ private static readonly Regex DoubleInfinity = new Regex("^-?inf(inity)?$",
+ SilverlightCompatibility.CompiledRegexWhereAvailable | RegexOptions.IgnoreCase);
+ private static readonly Regex FloatInfinity = new Regex("^-?inf(inity)?f?$",
+ SilverlightCompatibility.CompiledRegexWhereAvailable | RegexOptions.IgnoreCase);
+ private static readonly Regex FloatNan = new Regex("^nanf?$",
+ SilverlightCompatibility.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.InvariantCultureIgnoreCase)) {
+ NextToken();
+ return Double.NaN;
+ }
+
+ try {
+ double result = double.Parse(currentToken, CultureInfo.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, CultureInfo.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);
+ }
+ }
+}
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