diff --git a/src/CBot/CBotClass.cpp b/src/CBot/CBotClass.cpp
index b3778a7b..f1a658ad 100644
--- a/src/CBot/CBotClass.cpp
+++ b/src/CBot/CBotClass.cpp
@@ -192,7 +192,7 @@ bool CBotClass::AddItem(CBotVar* pVar)
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-std::string  CBotClass::GetName()
+const std::string&  CBotClass::GetName()
 {
     return m_name;
 }
diff --git a/src/CBot/CBotClass.h b/src/CBot/CBotClass.h
index bbdedefc..0f9a8ce4 100644
--- a/src/CBot/CBotClass.h
+++ b/src/CBot/CBotClass.h
@@ -173,7 +173,7 @@ public:
      * \brief GetName Gives the name of the class.
      * \return
      */
-    std::string GetName();
+    const std::string& GetName();
 
     /*!
      * \brief GetParent Gives the parent class (or nullptr).
diff --git a/src/CBot/CBotInstr/CBotFunction.cpp b/src/CBot/CBotInstr/CBotFunction.cpp
index 492711db..b4473cd8 100644
--- a/src/CBot/CBotInstr/CBotFunction.cpp
+++ b/src/CBot/CBotInstr/CBotFunction.cpp
@@ -996,7 +996,7 @@ bool CBotFunction::CheckParam(CBotDefParam* pParam)
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-std::string CBotFunction::GetName()
+const std::string& CBotFunction::GetName()
 {
     return  m_token.GetString();
 }
diff --git a/src/CBot/CBotInstr/CBotFunction.h b/src/CBot/CBotInstr/CBotFunction.h
index 90735158..b16780cd 100644
--- a/src/CBot/CBotInstr/CBotFunction.h
+++ b/src/CBot/CBotInstr/CBotFunction.h
@@ -207,7 +207,7 @@ public:
      * \brief GetName
      * \return
      */
-    std::string GetName();
+    const std::string& GetName();
 
     /*!
      * \brief GetParams
diff --git a/src/CBot/CBotToken.cpp b/src/CBot/CBotToken.cpp
index 6f402165..9663e299 100644
--- a/src/CBot/CBotToken.cpp
+++ b/src/CBot/CBotToken.cpp
@@ -21,13 +21,22 @@
 
 #include <cstdarg>
 #include <cassert>
+#include <boost/bimap.hpp>
 
 namespace CBot
 {
 
+namespace {
+    template <typename L, typename R>
+    boost::bimap<L, R> makeBimap(std::initializer_list<typename boost::bimap<L, R>::value_type> list)
+    {
+        return boost::bimap<L, R>(list.begin(), list.end());
+    }
+}
+
 //! \brief Keeps the string corresponding to keyword ID
 //! Map is filled with id-string pars that are needed for CBot language parsing
-static const std::map<TokenId, const std::string> KEYWORDS = {
+static const boost::bimap<TokenId, std::string> KEYWORDS = makeBimap<TokenId, std::string>({
     {ID_IF,         "if"},
     {ID_ELSE,       "else"},
     {ID_WHILE,      "while"},
@@ -115,7 +124,7 @@ static const std::map<TokenId, const std::string> KEYWORDS = {
     {ID_ASSMODULO,  "%="},
     {TX_UNDEF,      "undefined"},
     {TX_NAN,        "not a number"}
-};
+});
 
 namespace
 {
@@ -123,9 +132,10 @@ static const std::string emptyString = "";
 }
 const std::string& LoadString(TokenId id)
 {
-    if (KEYWORDS.find(id) != KEYWORDS.end())
+    auto it = KEYWORDS.left.find(id);
+    if (it != KEYWORDS.left.end())
     {
-        return KEYWORDS.at(id);
+        return it->second;
     }
     else
     {
@@ -210,7 +220,7 @@ long CBotToken::GetKeywordId()
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-std::string CBotToken::GetString()
+const std::string& CBotToken::GetString()
 {
     return m_text;
 }
@@ -242,6 +252,7 @@ void CBotToken::SetPos(int start, int end)
 
 ////////////////////////////////////////////////////////////////////////////////
 
+// TODO: CharInList could probably be optimized to conditions like (*c >= '0' && *c <= '9') to gain some performance
 static char    sep1[] = " \r\n\t,:()[]{}-+*/=;><!~^|&%.\"\'?";
 static char    sep2[] = " \r\n\t";                           // only separators
 static char    sep3[] = ",:()[]{}-+*/=;<>!~^|&%.?";          // operational separators
@@ -438,10 +449,10 @@ std::unique_ptr<CBotToken> CBotToken::CompileTokens(const std::string& program)
 ////////////////////////////////////////////////////////////////////////////////
 int CBotToken::GetKeyWord(const std::string& w)
 {
-    for (const auto& it : KEYWORDS)
-    {
-        if (it.second == w) return it.first;
-    }
+	auto it = KEYWORDS.right.find(w);
+	if (it != KEYWORDS.right.end()) {
+		return it->second;
+	}
 
     return -1;
 }
diff --git a/src/CBot/CBotToken.h b/src/CBot/CBotToken.h
index cfbda812..4dc7450a 100644
--- a/src/CBot/CBotToken.h
+++ b/src/CBot/CBotToken.h
@@ -120,7 +120,7 @@ public:
      * \brief Return the token string
      * \return The string associated with this token
      */
-    std::string GetString();
+    const std::string& GetString();
 
     /**
      * \brief Set the token string
diff --git a/src/CBot/CBotVar/CBotVar.cpp b/src/CBot/CBotVar/CBotVar.cpp
index 742ef598..62ba41f4 100644
--- a/src/CBot/CBotVar/CBotVar.cpp
+++ b/src/CBot/CBotVar/CBotVar.cpp
@@ -49,7 +49,7 @@ namespace CBot
 long CBotVar::m_identcpt = 0;
 
 ////////////////////////////////////////////////////////////////////////////////
-CBotVar::CBotVar( )
+CBotVar::CBotVar( ) : m_token(nullptr)
 {
     m_pMyThis = nullptr;
     m_pUserPtr = nullptr;
@@ -62,9 +62,17 @@ CBotVar::CBotVar( )
     m_mPrivate = ProtectionLevel::Public;
 }
 
-CBotVar::CBotVar(const CBotToken &name) : CBotVar()
+CBotVar::CBotVar(const CBotToken &name) : m_token(new CBotToken(name))
 {
-    m_token = new CBotToken(name);
+    m_pMyThis = nullptr;
+    m_pUserPtr = nullptr;
+    m_InitExpr = nullptr;
+    m_LimExpr = nullptr;
+    m_type  = -1;
+    m_binit = InitType::UNDEF;
+    m_ident = 0;
+    m_bStatic = false;
+    m_mPrivate = ProtectionLevel::Public;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -378,7 +386,7 @@ void CBotVar::SetInit(CBotVar::InitType initType)
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-std::string CBotVar::GetName()
+const std::string& CBotVar::GetName()
 {
     return    m_token->GetString();
 }
diff --git a/src/CBot/CBotVar/CBotVar.h b/src/CBot/CBotVar/CBotVar.h
index a023e2f9..d2805ddf 100644
--- a/src/CBot/CBotVar/CBotVar.h
+++ b/src/CBot/CBotVar/CBotVar.h
@@ -170,7 +170,7 @@ public:
      * \brief Returns the name of the variable
      * \return The name of the variable, empty string if unknown
      */
-    std::string GetName();
+    const std::string& GetName();
 
     /**
      * \brief SetName Changes the name of the variable
@@ -650,7 +650,7 @@ public:
 
 protected:
     //! The corresponding token, defines the variable name
-    CBotToken* m_token;
+    CBotToken* const m_token;
     //! Type of value.
     CBotTypResult m_type;
     //! Initialization status
diff --git a/src/CBot/CBotVar/CBotVarArray.cpp b/src/CBot/CBotVar/CBotVarArray.cpp
index cadfe1e5..6462d119 100644
--- a/src/CBot/CBotVar/CBotVarArray.cpp
+++ b/src/CBot/CBotVar/CBotVarArray.cpp
@@ -31,12 +31,11 @@ namespace CBot
 {
 
 ////////////////////////////////////////////////////////////////////////////////
-CBotVarArray::CBotVarArray(const CBotToken& name, CBotTypResult& type)
+CBotVarArray::CBotVarArray(const CBotToken& name, CBotTypResult& type) : CBotVar(name)
 {
     if ( !type.Eq(CBotTypArrayPointer) &&
          !type.Eq(CBotTypArrayBody)) assert(0);
 
-    m_token        = new CBotToken(name);
     m_next        = nullptr;
     m_pMyThis    = nullptr;
     m_pUserPtr    = nullptr;
diff --git a/src/CBot/CBotVar/CBotVarClass.cpp b/src/CBot/CBotVar/CBotVarClass.cpp
index 06944b51..36952d18 100644
--- a/src/CBot/CBotVar/CBotVarClass.cpp
+++ b/src/CBot/CBotVar/CBotVarClass.cpp
@@ -36,7 +36,7 @@ namespace CBot
 std::set<CBotVarClass*> CBotVarClass::m_instances{};
 
 ////////////////////////////////////////////////////////////////////////////////
-CBotVarClass::CBotVarClass(const CBotToken& name, const CBotTypResult& type)
+CBotVarClass::CBotVarClass(const CBotToken& name, const CBotTypResult& type) : CBotVar(name)
 {
     if ( !type.Eq(CBotTypClass)        &&
          !type.Eq(CBotTypIntrinsic)    &&                // by convenience there accepts these types
@@ -44,7 +44,6 @@ CBotVarClass::CBotVarClass(const CBotToken& name, const CBotTypResult& type)
          !type.Eq(CBotTypArrayPointer) &&
          !type.Eq(CBotTypArrayBody)) assert(0);
 
-    m_token        = new CBotToken(name);
     m_next        = nullptr;
     m_pMyThis    = nullptr;
     m_pUserPtr    = OBJECTCREATED;//nullptr;
diff --git a/src/CBot/CBotVar/CBotVarPointer.cpp b/src/CBot/CBotVar/CBotVarPointer.cpp
index afc81b93..2f78c90a 100644
--- a/src/CBot/CBotVar/CBotVarPointer.cpp
+++ b/src/CBot/CBotVar/CBotVarPointer.cpp
@@ -32,14 +32,13 @@ namespace CBot
 {
 
 ////////////////////////////////////////////////////////////////////////////////
-CBotVarPointer::CBotVarPointer(const CBotToken& name, CBotTypResult& type)
+CBotVarPointer::CBotVarPointer(const CBotToken& name, CBotTypResult& type) : CBotVar(name)
 {
     if ( !type.Eq(CBotTypPointer) &&
          !type.Eq(CBotTypNullPointer) &&
          !type.Eq(CBotTypClass)   &&                    // for convenience accepts Class and Intrinsic
          !type.Eq(CBotTypIntrinsic) ) assert(0);
 
-    m_token        = new CBotToken(name);
     m_next        = nullptr;
     m_pMyThis    = nullptr;
     m_pUserPtr    = nullptr;