diff options
Diffstat (limited to 'antlr4-cpp-runtime-4.9.2-source/runtime/src/atn/ATNConfigSet.h')
| -rw-r--r-- | antlr4-cpp-runtime-4.9.2-source/runtime/src/atn/ATNConfigSet.h | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/antlr4-cpp-runtime-4.9.2-source/runtime/src/atn/ATNConfigSet.h b/antlr4-cpp-runtime-4.9.2-source/runtime/src/atn/ATNConfigSet.h new file mode 100644 index 0000000..850a07c --- /dev/null +++ b/antlr4-cpp-runtime-4.9.2-source/runtime/src/atn/ATNConfigSet.h @@ -0,0 +1,110 @@ +/* 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 "support/BitSet.h" +#include "atn/PredictionContext.h" + +namespace antlr4 { +namespace atn { + + /// Specialized set that can track info about the set, with support for combining similar configurations using a + /// graph-structured stack. + class ANTLR4CPP_PUBLIC ATNConfigSet { + public: + /// Track the elements as they are added to the set; supports get(i) + std::vector<Ref<ATNConfig>> configs; + + // TODO: these fields make me pretty uncomfortable but nice to pack up info together, saves recomputation + // TODO: can we track conflicts as they are added to save scanning configs later? + size_t uniqueAlt; + + /** Currently this is only used when we detect SLL conflict; this does + * not necessarily represent the ambiguous alternatives. In fact, + * I should also point out that this seems to include predicated alternatives + * that have predicates that evaluate to false. Computed in computeTargetState(). + */ + antlrcpp::BitSet conflictingAlts; + + // Used in parser and lexer. In lexer, it indicates we hit a pred + // while computing a closure operation. Don't make a DFA state from this. + bool hasSemanticContext; + bool dipsIntoOuterContext; + + /// Indicates that this configuration set is part of a full context + /// LL prediction. It will be used to determine how to merge $. With SLL + /// it's a wildcard whereas it is not for LL context merge. + const bool fullCtx; + + ATNConfigSet(bool fullCtx = true); + ATNConfigSet(const Ref<ATNConfigSet> &old); + + virtual ~ATNConfigSet(); + + virtual bool add(const Ref<ATNConfig> &config); + + /// <summary> + /// Adding a new config means merging contexts with existing configs for + /// {@code (s, i, pi, _)}, where {@code s} is the + /// <seealso cref="ATNConfig#state"/>, {@code i} is the <seealso cref="ATNConfig#alt"/>, and + /// {@code pi} is the <seealso cref="ATNConfig#semanticContext"/>. We use + /// {@code (s,i,pi)} as key. + /// <p/> + /// This method updates <seealso cref="#dipsIntoOuterContext"/> and + /// <seealso cref="#hasSemanticContext"/> when necessary. + /// </summary> + virtual bool add(const Ref<ATNConfig> &config, PredictionContextMergeCache *mergeCache); + + virtual std::vector<ATNState *> getStates(); + + /** + * Gets the complete set of represented alternatives for the configuration + * set. + * + * @return the set of represented alternatives in this configuration set + * + * @since 4.3 + */ + antlrcpp::BitSet getAlts(); + virtual std::vector<Ref<SemanticContext>> getPredicates(); + + virtual Ref<ATNConfig> get(size_t i) const; + + virtual void optimizeConfigs(ATNSimulator *interpreter); + + bool addAll(const Ref<ATNConfigSet> &other); + + bool operator == (const ATNConfigSet &other); + virtual size_t hashCode(); + virtual size_t size(); + virtual bool isEmpty(); + virtual void clear(); + virtual bool isReadonly(); + virtual void setReadonly(bool readonly); + virtual std::string toString(); + + protected: + /// Indicates that the set of configurations is read-only. Do not + /// allow any code to manipulate the set; DFA states will point at + /// the sets and they must not change. This does not protect the other + /// fields; in particular, conflictingAlts is set after + /// we've made this readonly. + bool _readonly; + + virtual size_t getHash(ATNConfig *c); // Hash differs depending on set type. + + private: + size_t _cachedHashCode; + + /// All configs but hashed by (s, i, _, pi) not including context. Wiped out + /// when we go readonly as this set becomes a DFA state. + std::unordered_map<size_t, ATNConfig *> _configLookup; + + void InitializeInstanceFields(); + }; + +} // namespace atn +} // namespace antlr4 |
