Initial work on standard library

src/Evaluator/EvalValues/EvalValueHelper.hpp

@@ -49,7 +49,7 @@ namespace Porygon::Evaluation{
             return new BooleanEvalValue(b);
         }
         static EvalValue* Create(const string& s){
-            return new StringEvalValue(Utilities::StringUtils::StringToU16String(s));
+            return new StringEvalValue(Utilities::StringUtils::ToUTF8(s));
         }
         static EvalValue* Create(u16string s){
             return new StringEvalValue(std::move(s));

src/Evaluator/EvalValues/NilEvalValue.hpp

@@ -0,0 +1,25 @@
+#ifndef PORYGONLANG_NILEVALVALUE_HPP
+#define PORYGONLANG_NILEVALVALUE_HPP
+
+#include "EvalValue.hpp"
+
+namespace Porygon::Evaluation{
+    class NilEvalValue : public EvalValue{
+        const TypeClass GetTypeClass() const final{
+            return TypeClass ::Nil;
+        }
+        const bool operator==(EvalValue *b) const final{
+            return b->GetTypeClass() == TypeClass ::Nil;
+        }
+
+        const shared_ptr<EvalValue> Clone() const final{
+            return make_shared<NilEvalValue>();
+        }
+
+        const std::size_t GetHashCode() const final{
+            return 0;
+        }
+    };
+}
+
+#endif //PORYGONLANG_NILEVALVALUE_HPP

src/Evaluator/EvaluationException.hpp

@@ -11,14 +11,14 @@ namespace Porygon::Evaluation {
     class EvaluationException : public std::exception {
         string _message;
     public:
-        explicit EvaluationException(string message) {
-            _message = std::move(message);
+        explicit EvaluationException(const string& message) {
+            _message = defaultErrorText +message;
         }
 
         const string defaultErrorText = "An evaluation exception occurred: ";
 
         const char *what() const noexcept final {
-            return (defaultErrorText + _message).c_str();
+            return _message.c_str();
         }
     };
 }

src/Evaluator/EvaluationScope/EvaluationScope.cpp

@@ -1,5 +1,6 @@
 
 #include "EvaluationScope.hpp"
+#include "../../StandardLibraries/StaticScope.hpp"
 #include <memory>
 
 namespace Porygon::Evaluation {
@@ -29,8 +30,11 @@ namespace Porygon::Evaluation {
     }
 
     shared_ptr<EvalValue> EvaluationScope::GetVariable(const BoundVariableKey *key) {
-        if (key->GetScopeId() == 0) {
+        auto scopeId = key -> GetScopeId();
+        if (scopeId== 0) {
             return _scriptScope->at(key->GetIdentifier());
+        } else if(scopeId == -2){
+            return StandardLibraries::StaticScope::GetVariable(key->GetIdentifier());
         } else {
             return _localScope[key->GetHash()];
         }