From 79fbc8bf495770e4a8b7c66c46acf07f4e47e568 Mon Sep 17 00:00:00 2001
From: Roland Reichwein <mail@reichwein.it>
Date: Mon, 30 Mar 2020 18:33:01 +0200
Subject: Speed up compile

---
 grammer.h | 26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

(limited to 'grammer.h')

diff --git a/grammer.h b/grammer.h
index 88cb7b7..df7ff8d 100644
--- a/grammer.h
+++ b/grammer.h
@@ -5,6 +5,7 @@
 
 #include <cstdint>
 #include <deque>
+#include <tuple>
 #include <unordered_set>
 #include <utility>
 
@@ -41,8 +42,9 @@ private:
  BNF &bnf; // not const for access via operator[]
  const std::string m_top;
 
- std::unordered_map<std::string, std::set<std::string>> ReverseBNF; // possible parent types of a given type; unused now: remove?
- std::unordered_map<std::string, std::set<std::string>> reversedFirst; // possible parent types of first childs of a given type
+ //std::unordered_map<std::string, std::unordered_set<std::string>> ReverseBNF; // possible parent types of a given type; unused now: remove?
+ //std::unordered_map<std::string, std::unordered_set<std::string>> reversedFirst; // possible parent types of first childs of a given type
+ std::unordered_map<std::string, std::unordered_set<std::pair<std::string, index_t>, PairHash>> reversedPosFirst; // possible parent types of first childs of a given type
 
  std::deque<index_t> symbol_variants;
  decltype(symbol_variants)::iterator symbol_variants_it;
@@ -63,12 +65,26 @@ private:
  void IncNodePosition(NodePosition& pos);
 
  // top-down algorithm
- std::unordered_map<std::string, size_t> m_min; // cache
- size_t minimumSymbolsNeeded(std::string symbol);
- size_t minimumSymbolsNeeded(std::vector<std::string> symbol_list);
+ std::unordered_map<std::string, size_t> m_min; // cache for MinimumSymbolsNeeded
+ size_t minimumSymbolsNeeded(const std::string& symbol);
+ size_t minimumSymbolsNeeded(const std::vector<std::string>& symbol_list);
  bool match(std::string symbol, size_t begin, size_t end);
  bool match(std::vector<std::string> symbol_list, size_t begin, size_t end);
 
+ // start / end cache
+ struct TupleHash {
+  size_t operator()(const std::tuple<std::string,size_t,std::string>& t) const noexcept
+  {
+   size_t h0 {std::hash<std::string>{}(std::get<0>(t))};
+   size_t h1 {std::hash<size_t     >{}(std::get<1>(t))};
+   size_t h2 {std::hash<std::string>{}(std::get<2>(t))};
+   return h0 ^ (h1 << 1) ^ (h2 << 2);
+  }
+ };
+ std::unordered_set<std::tuple<std::string, size_t, std::string>, TupleHash> m_start_cache;
+ bool canStartWith(const std::string& non_terminal, size_t variant, const std::string& terminal) const;
+ void fillStartCache();
+
  void constructTree();
  std::vector<std::string> m_symbol_list;
  index_t m_symbol_list_pos{};
-- 
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