--- /dev/null
+/* 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 "RuleContext.h"
+#include "support/CPPUtils.h"
+
+namespace antlr4 {
+
+ /// <summary>
+ /// A rule invocation record for parsing.
+ ///
+ /// Contains all of the information about the current rule not stored in the
+ /// RuleContext. It handles parse tree children list, Any ATN state
+ /// tracing, and the default values available for rule invocatons:
+ /// start, stop, rule index, current alt number.
+ ///
+ /// Subclasses made for each rule and grammar track the parameters,
+ /// return values, locals, and labels specific to that rule. These
+ /// are the objects that are returned from rules.
+ ///
+ /// Note text is not an actual field of a rule return value; it is computed
+ /// from start and stop using the input stream's toString() method. I
+ /// could add a ctor to this so that we can pass in and store the input
+ /// stream, but I'm not sure we want to do that. It would seem to be undefined
+ /// to get the .text property anyway if the rule matches tokens from multiple
+ /// input streams.
+ ///
+ /// I do not use getters for fields of objects that are used simply to
+ /// group values such as this aggregate. The getters/setters are there to
+ /// satisfy the superclass interface.
+ /// </summary>
+ class ANTLR4CPP_PUBLIC ParserRuleContext : public RuleContext {
+ public:
+ static ParserRuleContext EMPTY;
+
+ /// <summary>
+ /// For debugging/tracing purposes, we want to track all of the nodes in
+ /// the ATN traversed by the parser for a particular rule.
+ /// This list indicates the sequence of ATN nodes used to match
+ /// the elements of the children list. This list does not include
+ /// ATN nodes and other rules used to match rule invocations. It
+ /// traces the rule invocation node itself but nothing inside that
+ /// other rule's ATN submachine.
+ ///
+ /// There is NOT a one-to-one correspondence between the children and
+ /// states list. There are typically many nodes in the ATN traversed
+ /// for each element in the children list. For example, for a rule
+ /// invocation there is the invoking state and the following state.
+ ///
+ /// The parser setState() method updates field s and adds it to this list
+ /// if we are debugging/tracing.
+ ///
+ /// This does not trace states visited during prediction.
+ /// </summary>
+ // public List<Integer> states;
+
+ Token *start;
+ Token *stop;
+
+ /// The exception that forced this rule to return. If the rule successfully
+ /// completed, this is "null exception pointer".
+ std::exception_ptr exception;
+
+ ParserRuleContext();
+ ParserRuleContext(ParserRuleContext *parent, size_t invokingStateNumber);
+ virtual ~ParserRuleContext() {}
+
+ /** COPY a ctx (I'm deliberately not using copy constructor) to avoid
+ * confusion with creating node with parent. Does not copy children
+ * (except error leaves).
+ */
+ virtual void copyFrom(ParserRuleContext *ctx);
+
+
+ // Double dispatch methods for listeners
+
+ virtual void enterRule(tree::ParseTreeListener *listener);
+ virtual void exitRule(tree::ParseTreeListener *listener);
+
+ /** Add a token leaf node child and force its parent to be this node. */
+ tree::TerminalNode* addChild(tree::TerminalNode *t);
+ RuleContext* addChild(RuleContext *ruleInvocation);
+
+ /// Used by enterOuterAlt to toss out a RuleContext previously added as
+ /// we entered a rule. If we have # label, we will need to remove
+ /// generic ruleContext object.
+ virtual void removeLastChild();
+
+ virtual tree::TerminalNode* getToken(size_t ttype, std::size_t i);
+
+ virtual std::vector<tree::TerminalNode *> getTokens(size_t ttype);
+
+ template<typename T>
+ T* getRuleContext(size_t i) {
+ if (children.empty()) {
+ return nullptr;
+ }
+
+ size_t j = 0; // what element have we found with ctxType?
+ for (auto &child : children) {
+ if (antlrcpp::is<T *>(child)) {
+ if (j++ == i) {
+ return dynamic_cast<T *>(child);
+ }
+ }
+ }
+ return nullptr;
+ }
+
+ template<typename T>
+ std::vector<T *> getRuleContexts() {
+ std::vector<T *> contexts;
+ for (auto *child : children) {
+ if (antlrcpp::is<T *>(child)) {
+ contexts.push_back(dynamic_cast<T *>(child));
+ }
+ }
+
+ return contexts;
+ }
+
+ virtual misc::Interval getSourceInterval() override;
+
+ /**
+ * Get the initial token in this context.
+ * Note that the range from start to stop is inclusive, so for rules that do not consume anything
+ * (for example, zero length or error productions) this token may exceed stop.
+ */
+ virtual Token *getStart();
+
+ /**
+ * Get the final token in this context.
+ * Note that the range from start to stop is inclusive, so for rules that do not consume anything
+ * (for example, zero length or error productions) this token may precede start.
+ */
+ virtual Token *getStop();
+
+ /// <summary>
+ /// Used for rule context info debugging during parse-time, not so much for ATN debugging </summary>
+ virtual std::string toInfoString(Parser *recognizer);
+ };
+
+} // namespace antlr4
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