X-Git-Url: https://gitweb.ps.run/toc/blobdiff_plain/9f94b672a5dc32da5ad01742bd4e976315a30d9c..c6ad2948bb98d42f8e0883ef82cd14cd2d5eda60:/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 new file mode 100644 index 0000000..a8ed34f --- /dev/null +++ b/antlr4-cpp-runtime-4.9.2-source/runtime/src/TokenSource.h @@ -0,0 +1,85 @@ +/* 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 { + + /// + /// A source of tokens must provide a sequence of tokens via + /// and also must reveal it's source of characters; 's text is + /// computed from a ; it only store indices into the char + /// stream. + ///

+ /// 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 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. + ///

+ class ANTLR4CPP_PUBLIC TokenSource { + public: + virtual ~TokenSource(); + + /// Return a object from your input stream (usually a + /// ). 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 nextToken() = 0; + + /// + /// Get the line number for the current position in the input stream. The + /// first line in the input is line 1. + /// + /// The line number for the current position in the input stream, or + /// 0 if the current token source does not track line numbers. + virtual size_t getLine() const = 0; + + /// + /// Get the index into the current line for the current position in the input + /// stream. The first character on a line has position 0. + /// + /// 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. + virtual size_t getCharPositionInLine() = 0; + + /// + /// Get the from which this token source is currently + /// providing tokens. + /// + /// The associated with the current position in + /// the input, or {@code null} if no input stream is available for the token + /// source. + virtual CharStream* getInputStream() = 0; + + /// + /// 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 . + /// + virtual std::string getSourceName() = 0; + + /// + /// Set the this token source should use for creating + /// objects from the input. + /// + /// The to use for creating tokens. + template + void setTokenFactory(TokenFactory * /*factory*/) {} + + /// + /// Gets the this token source is currently using for + /// creating objects from the input. + /// + /// The currently used by this token source. + virtual TokenFactory* getTokenFactory() = 0; + }; + +} // namespace antlr4