From 4511eab66574b8047376a1f612e84e57d2040a95 Mon Sep 17 00:00:00 2001
From: crupest <crupest@outlook.com>
Date: Sat, 11 Sep 2021 16:31:54 +0800
Subject: ...

---
 src/parse/Grammar.cpp | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

(limited to 'src')

diff --git a/src/parse/Grammar.cpp b/src/parse/Grammar.cpp
index 8d929212..a2dd14d4 100644
--- a/src/parse/Grammar.cpp
+++ b/src/parse/Grammar.cpp
@@ -35,4 +35,38 @@ Production* Grammar::CreateProduction(String name, Nonterminal* left,
   return production;
 }
 
+bool Grammar::RemoveSymbol(Symbol* symbol) {
+  for (auto production : productions_) {
+    if (production->GetLeft() == symbol) return false;
+    for (auto s : production->GetRight()) {
+      if (s == symbol) return false;
+    }
+  }
+
+  auto i = std::find(symbols_.begin(), symbols_.end(), symbol);
+
+  if (i == symbols_.cend()) return false;
+
+  symbols_.erase(i);
+
+  if (auto t = dynamic_cast<Terminal*>(symbol)) {
+    terminals_.erase(std::find(terminals_.begin(), terminals_.end(), t));
+  } else if (auto n = dynamic_cast<Nonterminal*>(symbol)) {
+    nonterminals_.erase(
+        std::find(nonterminals_.begin(), nonterminals_.end(), n));
+  }
+
+  delete symbol;
+
+  return true;
+}
+
+bool Grammar::RemoveProduction(Production* production) {
+  auto i = std::find(productions_.begin(), productions_.end(), production);
+  if (i == productions_.cend()) return false;
+  productions_.erase(i);
+  delete production;
+  return true;
+}
+
 }  // namespace cru::parse
-- 
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