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author | robot-piglet <robot-piglet@yandex-team.com> | 2023-12-02 01:45:21 +0300 |
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committer | robot-piglet <robot-piglet@yandex-team.com> | 2023-12-02 02:42:50 +0300 |
commit | 9c43d58f75cf086b744cf4fe2ae180e8f37e4a0c (patch) | |
tree | 9f88a486917d371d099cd712efd91b4c122d209d /contrib/libs/antlr4_cpp_runtime/src/Lexer.h | |
parent | 32fb6dda1feb24f9ab69ece5df0cb9ec238ca5e6 (diff) | |
download | ydb-9c43d58f75cf086b744cf4fe2ae180e8f37e4a0c.tar.gz |
Intermediate changes
Diffstat (limited to 'contrib/libs/antlr4_cpp_runtime/src/Lexer.h')
-rw-r--r-- | contrib/libs/antlr4_cpp_runtime/src/Lexer.h | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/contrib/libs/antlr4_cpp_runtime/src/Lexer.h b/contrib/libs/antlr4_cpp_runtime/src/Lexer.h new file mode 100644 index 0000000000..77033ad9e6 --- /dev/null +++ b/contrib/libs/antlr4_cpp_runtime/src/Lexer.h @@ -0,0 +1,196 @@ +/* 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 "Recognizer.h" +#include "TokenSource.h" +#include "CharStream.h" +#include "Token.h" + +namespace antlr4 { + + /// A lexer is recognizer that draws input symbols from a character stream. + /// lexer grammars result in a subclass of this object. A Lexer object + /// uses simplified match() and error recovery mechanisms in the interest + /// of speed. + class ANTLR4CPP_PUBLIC Lexer : public Recognizer, public TokenSource { + public: + static constexpr size_t DEFAULT_MODE = 0; + static constexpr size_t MORE = std::numeric_limits<size_t>::max() - 1; + static constexpr size_t SKIP = std::numeric_limits<size_t>::max() - 2; + + static constexpr size_t DEFAULT_TOKEN_CHANNEL = Token::DEFAULT_CHANNEL; + static constexpr size_t HIDDEN = Token::HIDDEN_CHANNEL; + static constexpr size_t MIN_CHAR_VALUE = 0; + static constexpr size_t MAX_CHAR_VALUE = 0x10FFFF; + + CharStream *_input; // Pure reference, usually from statically allocated instance. + + protected: + /// How to create token objects. + TokenFactory<CommonToken> *_factory; + + public: + /// The goal of all lexer rules/methods is to create a token object. + /// This is an instance variable as multiple rules may collaborate to + /// create a single token. nextToken will return this object after + /// matching lexer rule(s). If you subclass to allow multiple token + /// emissions, then set this to the last token to be matched or + /// something nonnull so that the auto token emit mechanism will not + /// emit another token. + + // Life cycle of a token is this: + // Created by emit() (via the token factory) or by action code, holding ownership of it. + // Ownership is handed over to the token stream when calling nextToken(). + std::unique_ptr<Token> token; + + /// <summary> + /// What character index in the stream did the current token start at? + /// Needed, for example, to get the text for current token. Set at + /// the start of nextToken. + /// </summary> + size_t tokenStartCharIndex; + + /// <summary> + /// The line on which the first character of the token resides </summary> + size_t tokenStartLine; + + /// The character position of first character within the line. + size_t tokenStartCharPositionInLine; + + /// Once we see EOF on char stream, next token will be EOF. + /// If you have DONE : EOF ; then you see DONE EOF. + bool hitEOF; + + /// The channel number for the current token. + size_t channel; + + /// The token type for the current token. + size_t type; + + // Use the vector as a stack. + std::vector<size_t> modeStack; + size_t mode; + + Lexer(); + Lexer(CharStream *input); + virtual ~Lexer() {} + + virtual void reset(); + + /// Return a token from this source; i.e., match a token on the char stream. + virtual std::unique_ptr<Token> nextToken() override; + + /// Instruct the lexer to skip creating a token for current lexer rule + /// and look for another token. nextToken() knows to keep looking when + /// a lexer rule finishes with token set to SKIP_TOKEN. Recall that + /// if token == null at end of any token rule, it creates one for you + /// and emits it. + virtual void skip(); + virtual void more(); + virtual void setMode(size_t m); + virtual void pushMode(size_t m); + virtual size_t popMode(); + + template<typename T1> + void setTokenFactory(TokenFactory<T1> *factory) { + this->_factory = factory; + } + + virtual TokenFactory<CommonToken>* getTokenFactory() override; + + /// Set the char stream and reset the lexer + virtual void setInputStream(IntStream *input) override; + + virtual std::string getSourceName() override; + + virtual CharStream* getInputStream() override; + + /// By default does not support multiple emits per nextToken invocation + /// for efficiency reasons. Subclasses can override this method, nextToken, + /// and getToken (to push tokens into a list and pull from that list + /// rather than a single variable as this implementation does). + virtual void emit(std::unique_ptr<Token> newToken); + + /// The standard method called to automatically emit a token at the + /// outermost lexical rule. The token object should point into the + /// char buffer start..stop. If there is a text override in 'text', + /// use that to set the token's text. Override this method to emit + /// custom Token objects or provide a new factory. + virtual Token* emit(); + + virtual Token* emitEOF(); + + virtual size_t getLine() const override; + + virtual size_t getCharPositionInLine() override; + + virtual void setLine(size_t line); + + virtual void setCharPositionInLine(size_t charPositionInLine); + + /// What is the index of the current character of lookahead? + virtual size_t getCharIndex(); + + /// Return the text matched so far for the current token or any + /// text override. + virtual std::string getText(); + + /// Set the complete text of this token; it wipes any previous + /// changes to the text. + virtual void setText(const std::string &text); + + /// Override if emitting multiple tokens. + virtual std::unique_ptr<Token> getToken(); + + virtual void setToken(std::unique_ptr<Token> newToken); + + virtual void setType(size_t ttype); + + virtual size_t getType(); + + virtual void setChannel(size_t newChannel); + + virtual size_t getChannel(); + + virtual const std::vector<std::string>& getChannelNames() const = 0; + + virtual const std::vector<std::string>& getModeNames() const = 0; + + /// Return a list of all Token objects in input char stream. + /// Forces load of all tokens. Does not include EOF token. + virtual std::vector<std::unique_ptr<Token>> getAllTokens(); + + virtual void recover(const LexerNoViableAltException &e); + + virtual void notifyListeners(const LexerNoViableAltException &e); + + virtual std::string getErrorDisplay(const std::string &s); + + /// Lexers can normally match any char in it's vocabulary after matching + /// a token, so do the easy thing and just kill a character and hope + /// it all works out. You can instead use the rule invocation stack + /// to do sophisticated error recovery if you are in a fragment rule. + virtual void recover(RecognitionException *re); + + /// <summary> + /// Gets the number of syntax errors reported during parsing. This value is + /// incremented each time <seealso cref="#notifyErrorListeners"/> is called. + /// </summary> + /// <seealso cref= #notifyListeners </seealso> + virtual size_t getNumberOfSyntaxErrors(); + + protected: + /// You can set the text for the current token to override what is in + /// the input char buffer (via setText()). + std::string _text; + + private: + size_t _syntaxErrors; + void InitializeInstanceFields(); + }; + +} // namespace antlr4 |