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[toc] / antlr4-cpp-runtime-4.9.2-source / runtime / src / TokenSource.h

diff --git a/antlr4-cpp-runtime-4.9.2-source/runtime/src/TokenSource.h b/antlr4-cpp-runtime-4.9.2-source/runtime/src/TokenSource.h
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+/* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+ * Use of this file is governed by the BSD 3-clause license that
+ * can be found in the LICENSE.txt file in the project root.
+ */
+
+#pragma once
+
+#include "TokenFactory.h"
+
+namespace antlr4 {
+
+  /// <summary>
+  /// A source of tokens must provide a sequence of tokens via <seealso cref="#nextToken()"/>
+  /// and also must reveal it's source of characters; <seealso cref="CommonToken"/>'s text is
+  /// computed from a <seealso cref="CharStream"/>; it only store indices into the char
+  /// stream.
+  /// <p/>
+  /// Errors from the lexer are never passed to the parser. Either you want to keep
+  /// going or you do not upon token recognition error. If you do not want to
+  /// continue lexing then you do not want to continue parsing. Just throw an
+  /// exception not under <seealso cref="RecognitionException"/> and Java will naturally toss
+  /// you all the way out of the recognizers. If you want to continue lexing then
+  /// you should not throw an exception to the parser--it has already requested a
+  /// token. Keep lexing until you get a valid one. Just report errors and keep
+  /// going, looking for a valid token.
+  /// </summary>
+  class ANTLR4CPP_PUBLIC TokenSource {
+  public:
+    virtual ~TokenSource();
+
+    /// Return a <seealso cref="Token"/> object from your input stream (usually a
+    /// <seealso cref="CharStream"/>). Do not fail/return upon lexing error; keep chewing
+    /// on the characters until you get a good one; errors are not passed through
+    /// to the parser.
+    virtual std::unique_ptr<Token> nextToken() = 0;
+
+    /// <summary>
+    /// Get the line number for the current position in the input stream. The
+    /// first line in the input is line 1.
+    /// </summary>
+    /// <returns> The line number for the current position in the input stream, or
+    /// 0 if the current token source does not track line numbers. </returns>
+    virtual size_t getLine() const = 0;
+
+    /// <summary>
+    /// Get the index into the current line for the current position in the input
+    /// stream. The first character on a line has position 0.
+    /// </summary>
+    /// <returns> The line number for the current position in the input stream, or
+    /// (sze_t)-1 if the current token source does not track character positions. </returns>
+    virtual size_t getCharPositionInLine() = 0;
+
+    /// <summary>
+    /// Get the <seealso cref="CharStream"/> from which this token source is currently
+    /// providing tokens.
+    /// </summary>
+    /// <returns> The <seealso cref="CharStream"/> associated with the current position in
+    /// the input, or {@code null} if no input stream is available for the token
+    /// source. </returns>
+    virtual CharStream* getInputStream() = 0;
+
+    /// <summary>
+    /// Gets the name of the underlying input source. This method returns a
+    /// non-null, non-empty string. If such a name is not known, this method
+    /// returns <seealso cref="IntStream#UNKNOWN_SOURCE_NAME"/>.
+    /// </summary>
+    virtual std::string getSourceName() = 0;
+
+    /// <summary>
+    /// Set the <seealso cref="TokenFactory"/> this token source should use for creating
+    /// <seealso cref="Token"/> objects from the input.
+    /// </summary>
+    /// <param name="factory"> The <seealso cref="TokenFactory"/> to use for creating tokens. </param>
+    template<typename T1>
+    void setTokenFactory(TokenFactory<T1> * /*factory*/) {}
+
+    /// <summary>
+    /// Gets the <seealso cref="TokenFactory"/> this token source is currently using for
+    /// creating <seealso cref="Token"/> objects from the input.
+    /// </summary>
+    /// <returns> The <seealso cref="TokenFactory"/> currently used by this token source. </returns>
+    virtual TokenFactory<CommonToken>* getTokenFactory() = 0;
+  };
+
+} // namespace antlr4