From 9f0aa0b06666dc99515a4250085b31f0efa81af8 Mon Sep 17 00:00:00 2001
From: crupest <crupest@outlook.com>
Date: Sat, 11 Sep 2021 17:16:51 +0800
Subject: ...

---
 include/cru/parse/Grammar.hpp |  4 ++++
 src/parse/Grammar.cpp         | 10 ++++++++++
 2 files changed, 14 insertions(+)

diff --git a/include/cru/parse/Grammar.hpp b/include/cru/parse/Grammar.hpp
index 42649c30..98bed1b1 100644
--- a/include/cru/parse/Grammar.hpp
+++ b/include/cru/parse/Grammar.hpp
@@ -1,6 +1,7 @@
 #pragma once
 #include "Production.hpp"
 
+#include <unordered_map>
 #include <vector>
 
 namespace cru::parse {
@@ -38,6 +39,9 @@ class Grammar : public Object {
   Grammar* Clone() const;
 
  public:  // Algorithms
+  std::unordered_map<Nonterminal*, std::vector<Production*>>
+  GenerateLeftProductionMap() const;
+
   void EliminateLeftRecursions();
 
  private:
diff --git a/src/parse/Grammar.cpp b/src/parse/Grammar.cpp
index 5486542b..8253c3c3 100644
--- a/src/parse/Grammar.cpp
+++ b/src/parse/Grammar.cpp
@@ -112,4 +112,14 @@ Grammar* Grammar::Clone() const {
   return g;
 }
 
+std::unordered_map<Nonterminal*, std::vector<Production*>>
+Grammar::GenerateLeftProductionMap() const {
+  std::unordered_map<Nonterminal*, std::vector<Production*>> result;
+  for (auto p : productions_) {
+    result[p->GetLeft()].push_back(p);
+  }
+  return result;
+}
+
+void Grammar::EliminateLeftRecursions() {}
 }  // namespace cru::parse
-- 
cgit v1.2.3