style(sema): 规范符号表代码位置

src/sem/Sema.h

@@ -1,4 +1,4 @@
-// 基于语法树的极简语义检查与名称绑定。
+// 基于语法树的语义检查与名称绑定。
 #pragma once
 
 #include <unordered_map>

src/sem/SymbolTable.cpp

@@ -3,3 +3,17 @@
 // - 变量/函数/参数/常量的注册、查找与遮蔽规则
 
 #include "sem/SymbolTable.h"
+
+void SymbolTable::Add(const std::string& name,
+                      SysYParser::VarDeclContext* decl) {
+  table_[name] = decl;
+}
+
+bool SymbolTable::Contains(const std::string& name) const {
+  return table_.find(name) != table_.end();
+}
+
+SysYParser::VarDeclContext* SymbolTable::Lookup(const std::string& name) const {
+  auto it = table_.find(name);
+  return it == table_.end() ? nullptr : it->second;
+}

src/sem/SymbolTable.h

@@ -8,16 +8,9 @@
 
 class SymbolTable {
  public:
-  void Add(const std::string& name, SysYParser::VarDeclContext* decl) {
-    table_[name] = decl;
-  }
-  bool Contains(const std::string& name) const {
-    return table_.find(name) != table_.end();
-  }
-  SysYParser::VarDeclContext* Lookup(const std::string& name) const {
-    auto it = table_.find(name);
-    return it == table_.end() ? nullptr : it->second;
-  }
+  void Add(const std::string& name, SysYParser::VarDeclContext* decl);
+  bool Contains(const std::string& name) const;
+  SysYParser::VarDeclContext* Lookup(const std::string& name) const;
 
  private:
   std::unordered_map<std::string, SysYParser::VarDeclContext*> table_;