X-Git-Url: https://gitweb.ps.run/toc/blobdiff_plain/9f94b672a5dc32da5ad01742bd4e976315a30d9c..c6ad2948bb98d42f8e0883ef82cd14cd2d5eda60:/antlr4-cpp-runtime-4.9.2-source/runtime/src/tree/pattern/ParseTreePatternMatcher.h diff --git a/antlr4-cpp-runtime-4.9.2-source/runtime/src/tree/pattern/ParseTreePatternMatcher.h b/antlr4-cpp-runtime-4.9.2-source/runtime/src/tree/pattern/ParseTreePatternMatcher.h new file mode 100644 index 0000000..e77c7bc --- /dev/null +++ b/antlr4-cpp-runtime-4.9.2-source/runtime/src/tree/pattern/ParseTreePatternMatcher.h @@ -0,0 +1,185 @@ +/* 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 { + + /// + /// A tree pattern matching mechanism for ANTLR s. + ///

+ /// Patterns are strings of source input text with special tags representing + /// token or rule references such as: + ///

+ /// {@code = ;} + ///

+ /// Given a pattern start rule such as {@code statement}, this object constructs + /// a with placeholders for the {@code ID} and {@code expr} + /// subtree. Then the routines can compare an actual + /// from a parse with this pattern. Tag {@code } matches + /// any {@code ID} token and tag {@code } references the result of the + /// {@code expr} rule (generally an instance of {@code ExprContext}. + ///

+ /// 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}. + ///

+ /// The routines return {@code true} or {@code false} based + /// upon a match for the tree rooted at the parameter sent in. The + /// routines return a 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 + /// set to the first tree node that did not + /// match. + ///

+ /// For efficiency, you can compile a tree pattern in string form to a + /// object. + ///

+ /// See {@code TestParseTreeMatcher} for lots of examples. + /// has two static helper methods: + /// and that + /// are easy to use but not super efficient because they create new + /// objects each time and have to compile the + /// pattern in string form before using it. + ///

+ /// The lexer and parser that you pass into the + /// constructor are used to parse the pattern in string form. The lexer converts + /// the {@code = ;} 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 + /// 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. + ///

+ /// Normally a parser does not accept token {@code } as a valid + /// {@code expr} but, from the parser passed in, we create a special version of + /// the underlying grammar representation (an ) that allows imaginary + /// tokens representing rules ({@code }) to match entire rules. We call + /// these bypass alternatives. + ///

+ /// Delimiters are {@code <} and {@code >}, with {@code \} as the escape string + /// by default, but you can set them to whatever you want using + /// . You must escape both start and stop strings + /// {@code \<} and {@code \>}. + ///

+ 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 or from a and + /// 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(); + + /// + /// Set the delimiters used for marking rule and token tags within concrete + /// syntax used by the tree pattern parser. + /// + /// The start delimiter. + /// The stop delimiter. + /// The escape sequence to use for escaping a start or stop delimiter. + /// + /// if {@code start} is {@code null} or empty. + /// if {@code stop} is {@code null} or empty. + virtual void setDelimiters(const std::string &start, const std::string &stop, const std::string &escapeLeft); + + /// + /// Does {@code pattern} matched as rule {@code patternRuleIndex} match {@code tree}? + virtual bool matches(ParseTree *tree, const std::string &pattern, int patternRuleIndex); + + /// + /// Does {@code pattern} matched as rule patternRuleIndex match tree? Pass in a + /// compiled pattern instead of a string representation of a tree pattern. + /// + virtual bool matches(ParseTree *tree, const ParseTreePattern &pattern); + + /// + /// Compare {@code pattern} matched as rule {@code patternRuleIndex} against + /// {@code tree} and return a object that contains the + /// matched elements, or the node at which the match failed. + /// + virtual ParseTreeMatch match(ParseTree *tree, const std::string &pattern, int patternRuleIndex); + + /// + /// Compare {@code pattern} matched against {@code tree} and return a + /// 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. + /// + virtual ParseTreeMatch match(ParseTree *tree, const ParseTreePattern &pattern); + + /// + /// For repeated use of a tree pattern, compile it to a + /// using this method. + /// + virtual ParseTreePattern compile(const std::string &pattern, int patternRuleIndex); + + /// + /// Used to convert the tree pattern string into a series of tokens. The + /// input stream is reset. + /// + virtual Lexer* getLexer(); + + /// + /// Used to collect to the grammar file name, token names, rule names for + /// used to parse the pattern into a parse tree. + /// + virtual Parser* getParser(); + + // ---- SUPPORT CODE ---- + + virtual std::vector> tokenize(const std::string &pattern); + + /// Split " = ;" into 4 chunks for tokenizing by tokenize(). + virtual std::vector 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.}. + /// + /// 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. + virtual ParseTree* matchImpl(ParseTree *tree, ParseTree *patternTree, std::map> &labels); + + /// Is t subtree? + virtual RuleTagToken* getRuleTagToken(ParseTree *t); + + private: + Lexer *_lexer; + Parser *_parser; + + void InitializeInstanceFields(); + }; + +} // namespace pattern +} // namespace tree +} // namespace antlr4