X-Git-Url: https://gitweb.ps.run/toc/blobdiff_plain/9f94b672a5dc32da5ad01742bd4e976315a30d9c..c6ad2948bb98d42f8e0883ef82cd14cd2d5eda60:/antlr4-cpp-runtime-4.9.2-source/runtime/src/atn/LL1Analyzer.h

diff --git a/antlr4-cpp-runtime-4.9.2-source/runtime/src/atn/LL1Analyzer.h b/antlr4-cpp-runtime-4.9.2-source/runtime/src/atn/LL1Analyzer.h
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+++ b/antlr4-cpp-runtime-4.9.2-source/runtime/src/atn/LL1Analyzer.h
@@ -0,0 +1,115 @@
+/* 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 "Token.h"
+#include "support/BitSet.h"
+#include "atn/PredictionContext.h"
+#include "atn/ATNConfig.h"
+
+namespace antlr4 {
+namespace atn {
+
+  class ANTLR4CPP_PUBLIC LL1Analyzer {
+  public:
+    /// Special value added to the lookahead sets to indicate that we hit
+    ///  a predicate during analysis if {@code seeThruPreds==false}.
+#if __cplusplus >= 201703L
+    static constexpr size_t HIT_PRED = Token::INVALID_TYPE;
+#else
+    enum : size_t {
+      HIT_PRED = Token::INVALID_TYPE,
+    };
+#endif
+
+    const atn::ATN &_atn;
+
+    LL1Analyzer(const atn::ATN &atn);
+    virtual ~LL1Analyzer();
+
+    /// <summary>
+    /// Calculates the SLL(1) expected lookahead set for each outgoing transition
+    /// of an <seealso cref="ATNState"/>. The returned array has one element for each
+    /// outgoing transition in {@code s}. If the closure from transition
+    /// <em>i</em> leads to a semantic predicate before matching a symbol, the
+    /// element at index <em>i</em> of the result will be {@code null}.
+    /// </summary>
+    /// <param name="s"> the ATN state </param>
+    /// <returns> the expected symbols for each outgoing transition of {@code s}. </returns>
+    virtual std::vector<misc::IntervalSet> getDecisionLookahead(ATNState *s) const;
+
+    /// <summary>
+    /// Compute set of tokens that can follow {@code s} in the ATN in the
+    /// specified {@code ctx}.
+    /// <p/>
+    /// If {@code ctx} is {@code null} and the end of the rule containing
+    /// {@code s} is reached, <seealso cref="Token#EPSILON"/> is added to the result set.
+    /// If {@code ctx} is not {@code null} and the end of the outermost rule is
+    /// reached, <seealso cref="Token#EOF"/> is added to the result set.
+    /// </summary>
+    /// <param name="s"> the ATN state </param>
+    /// <param name="ctx"> the complete parser context, or {@code null} if the context
+    /// should be ignored
+    /// </param>
+    /// <returns> The set of tokens that can follow {@code s} in the ATN in the
+    /// specified {@code ctx}. </returns>
+    virtual misc::IntervalSet LOOK(ATNState *s, RuleContext *ctx) const;
+
+    /// <summary>
+    /// Compute set of tokens that can follow {@code s} in the ATN in the
+    /// specified {@code ctx}.
+    /// <p/>
+    /// If {@code ctx} is {@code null} and the end of the rule containing
+    /// {@code s} is reached, <seealso cref="Token#EPSILON"/> is added to the result set.
+    /// If {@code ctx} is not {@code null} and the end of the outermost rule is
+    /// reached, <seealso cref="Token#EOF"/> is added to the result set.
+    /// </summary>
+    /// <param name="s"> the ATN state </param>
+    /// <param name="stopState"> the ATN state to stop at. This can be a
+    /// <seealso cref="BlockEndState"/> to detect epsilon paths through a closure. </param>
+    /// <param name="ctx"> the complete parser context, or {@code null} if the context
+    /// should be ignored
+    /// </param>
+    /// <returns> The set of tokens that can follow {@code s} in the ATN in the
+    /// specified {@code ctx}. </returns>
+    virtual misc::IntervalSet LOOK(ATNState *s, ATNState *stopState, RuleContext *ctx) const;
+
+    /// <summary>
+    /// Compute set of tokens that can follow {@code s} in the ATN in the
+    /// specified {@code ctx}.
+    /// <p/>
+    /// If {@code ctx} is {@code null} and {@code stopState} or the end of the
+    /// rule containing {@code s} is reached, <seealso cref="Token#EPSILON"/> is added to
+    /// the result set. If {@code ctx} is not {@code null} and {@code addEOF} is
+    /// {@code true} and {@code stopState} or the end of the outermost rule is
+    /// reached, <seealso cref="Token#EOF"/> is added to the result set.
+    /// </summary>
+    /// <param name="s"> the ATN state. </param>
+    /// <param name="stopState"> the ATN state to stop at. This can be a
+    /// <seealso cref="BlockEndState"/> to detect epsilon paths through a closure. </param>
+    /// <param name="ctx"> The outer context, or {@code null} if the outer context should
+    /// not be used. </param>
+    /// <param name="look"> The result lookahead set. </param>
+    /// <param name="lookBusy"> A set used for preventing epsilon closures in the ATN
+    /// from causing a stack overflow. Outside code should pass
+    /// {@code new HashSet<ATNConfig>} for this argument. </param>
+    /// <param name="calledRuleStack"> A set used for preventing left recursion in the
+    /// ATN from causing a stack overflow. Outside code should pass
+    /// {@code new BitSet()} for this argument. </param>
+    /// <param name="seeThruPreds"> {@code true} to true semantic predicates as
+    /// implicitly {@code true} and "see through them", otherwise {@code false}
+    /// to treat semantic predicates as opaque and add <seealso cref="#HIT_PRED"/> to the
+    /// result if one is encountered. </param>
+    /// <param name="addEOF"> Add <seealso cref="Token#EOF"/> to the result if the end of the
+    /// outermost context is reached. This parameter has no effect if {@code ctx}
+    /// is {@code null}. </param>
+  protected:
+    virtual void _LOOK(ATNState *s, ATNState *stopState, Ref<PredictionContext> const& ctx, misc::IntervalSet &look,
+      ATNConfig::Set &lookBusy, antlrcpp::BitSet &calledRuleStack, bool seeThruPreds, bool addEOF) const;
+  };
+
+} // namespace atn
+} // namespace antlr4