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contrib/libs/antlr4_cpp_runtime/src/tree/pattern/ParseTreePatternMatcher.h
185 строк
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Anton Myagkov
Update ydb version to 24.4 (#4579)
07 фев 2026, 11:59
Не верифицирован
07 фев 2026, 11:59
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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 "Exceptions.h" namespace antlr4 { namespace tree { namespace pattern { /// <summary> /// A tree pattern matching mechanism for ANTLR <seealso cref="ParseTree"/>s. /// <p/> /// Patterns are strings of source input text with special tags representing /// token or rule references such as: /// <p/> /// {@code <ID> = <expr>;} /// <p/> /// Given a pattern start rule such as {@code statement}, this object constructs /// a <seealso cref="ParseTree"/> with placeholders for the {@code ID} and {@code expr} /// subtree. Then the <seealso cref="#match"/> routines can compare an actual /// <seealso cref="ParseTree"/> from a parse with this pattern. Tag {@code <ID>} matches /// any {@code ID} token and tag {@code <expr>} references the result of the /// {@code expr} rule (generally an instance of {@code ExprContext}. /// <p/> /// Pattern {@code x = 0;} is a similar pattern that matches the same pattern /// except that it requires the identifier to be {@code x} and the expression to /// be {@code 0}. /// <p/> /// The <seealso cref="#matches"/> routines return {@code true} or {@code false} based /// upon a match for the tree rooted at the parameter sent in. The /// <seealso cref="#match"/> routines return a <seealso cref="ParseTreeMatch"/> object that /// contains the parse tree, the parse tree pattern, and a map from tag name to /// matched nodes (more below). A subtree that fails to match, returns with /// <seealso cref="ParseTreeMatch#mismatchedNode"/> set to the first tree node that did not /// match. /// <p/> /// For efficiency, you can compile a tree pattern in string form to a /// <seealso cref="ParseTreePattern"/> object. /// <p/> /// See {@code TestParseTreeMatcher} for lots of examples. /// <seealso cref="ParseTreePattern"/> has two static helper methods: /// <seealso cref="ParseTreePattern#findAll"/> and <seealso cref="ParseTreePattern#match"/> that /// are easy to use but not super efficient because they create new /// <seealso cref="ParseTreePatternMatcher"/> objects each time and have to compile the /// pattern in string form before using it. /// <p/> /// The lexer and parser that you pass into the <seealso cref="ParseTreePatternMatcher"/> /// constructor are used to parse the pattern in string form. The lexer converts /// the {@code <ID> = <expr>;} into a sequence of four tokens (assuming lexer /// throws out whitespace or puts it on a hidden channel). Be aware that the /// input stream is reset for the lexer (but not the parser; a /// <seealso cref="ParserInterpreter"/> is created to parse the input.). Any user-defined /// fields you have put into the lexer might get changed when this mechanism asks /// it to scan the pattern string. /// <p/> /// Normally a parser does not accept token {@code <expr>} as a valid /// {@code expr} but, from the parser passed in, we create a special version of /// the underlying grammar representation (an <seealso cref="ATN"/>) that allows imaginary /// tokens representing rules ({@code <expr>}) to match entire rules. We call /// these <em>bypass alternatives</em>. /// <p/> /// Delimiters are {@code <} and {@code >}, with {@code \} as the escape string /// by default, but you can set them to whatever you want using /// <seealso cref="#setDelimiters"/>. You must escape both start and stop strings /// {@code \<} and {@code \>}. /// </summary> class ANTLR4CPP_PUBLIC ParseTreePatternMatcher { public: class CannotInvokeStartRule : public RuntimeException { public: CannotInvokeStartRule(const RuntimeException &e); ~CannotInvokeStartRule(); }; // Fixes https://github.com/antlr/antlr4/issues/413 // "Tree pattern compilation doesn't check for a complete parse" class StartRuleDoesNotConsumeFullPattern : public RuntimeException { public: StartRuleDoesNotConsumeFullPattern() = default; StartRuleDoesNotConsumeFullPattern(StartRuleDoesNotConsumeFullPattern const&) = default; ~StartRuleDoesNotConsumeFullPattern(); StartRuleDoesNotConsumeFullPattern& operator=(StartRuleDoesNotConsumeFullPattern const&) = default; }; /// Constructs a <seealso cref="ParseTreePatternMatcher"/> or from a <seealso cref="Lexer"/> and /// <seealso cref="Parser"/> object. The lexer input stream is altered for tokenizing /// the tree patterns. The parser is used as a convenient mechanism to get /// the grammar name, plus token, rule names. ParseTreePatternMatcher(Lexer *lexer, Parser *parser); virtual ~ParseTreePatternMatcher(); /// <summary> /// Set the delimiters used for marking rule and token tags within concrete /// syntax used by the tree pattern parser. /// </summary> /// <param name="start"> The start delimiter. </param> /// <param name="stop"> The stop delimiter. </param> /// <param name="escapeLeft"> The escape sequence to use for escaping a start or stop delimiter. /// </param> /// <exception cref="IllegalArgumentException"> if {@code start} is {@code null} or empty. </exception> /// <exception cref="IllegalArgumentException"> if {@code stop} is {@code null} or empty. </exception> virtual void setDelimiters(const std::string &start, const std::string &stop, const std::string &escapeLeft); /// <summary> /// Does {@code pattern} matched as rule {@code patternRuleIndex} match {@code tree}? </summary> virtual bool matches(ParseTree *tree, const std::string &pattern, int patternRuleIndex); /// <summary> /// Does {@code pattern} matched as rule patternRuleIndex match tree? Pass in a /// compiled pattern instead of a string representation of a tree pattern. /// </summary> virtual bool matches(ParseTree *tree, const ParseTreePattern &pattern); /// <summary> /// Compare {@code pattern} matched as rule {@code patternRuleIndex} against /// {@code tree} and return a <seealso cref="ParseTreeMatch"/> object that contains the /// matched elements, or the node at which the match failed. /// </summary> virtual ParseTreeMatch match(ParseTree *tree, const std::string &pattern, int patternRuleIndex); /// <summary> /// Compare {@code pattern} matched against {@code tree} and return a /// <seealso cref="ParseTreeMatch"/> object that contains the matched elements, or the /// node at which the match failed. Pass in a compiled pattern instead of a /// string representation of a tree pattern. /// </summary> virtual ParseTreeMatch match(ParseTree *tree, const ParseTreePattern &pattern); /// <summary> /// For repeated use of a tree pattern, compile it to a /// <seealso cref="ParseTreePattern"/> using this method. /// </summary> virtual ParseTreePattern compile(const std::string &pattern, int patternRuleIndex); /// <summary> /// Used to convert the tree pattern string into a series of tokens. The /// input stream is reset. /// </summary> virtual Lexer* getLexer(); /// <summary> /// Used to collect to the grammar file name, token names, rule names for /// used to parse the pattern into a parse tree. /// </summary> virtual Parser* getParser(); // ---- SUPPORT CODE ---- virtual std::vector<std::unique_ptr<Token>> tokenize(const std::string &pattern); /// Split "<ID> = <e:expr>;" into 4 chunks for tokenizing by tokenize(). virtual std::vector<Chunk> split(const std::string &pattern); protected: std::string _start; std::string _stop; std::string _escape; // e.g., \< and \> must escape BOTH! /// Recursively walk {@code tree} against {@code patternTree}, filling /// {@code match.}<seealso cref="ParseTreeMatch#labels labels"/>. /// /// <returns> the first node encountered in {@code tree} which does not match /// a corresponding node in {@code patternTree}, or {@code null} if the match /// was successful. The specific node returned depends on the matching /// algorithm used by the implementation, and may be overridden. </returns> virtual ParseTree* matchImpl(ParseTree *tree, ParseTree *patternTree, std::map<std::string, std::vector<ParseTree *>> &labels); /// Is t <expr> subtree? virtual RuleTagToken* getRuleTagToken(ParseTree *t); private: Lexer *_lexer; Parser *_parser; void InitializeInstanceFields(); }; } // namespace pattern } // namespace tree } // namespace antlr4