Add partial return analysis

src/analysis.cpp

@@ -369,6 +369,14 @@ AnalysisResult analyze(Node &ast, Memory &memory) {
 
                 return get<0>(get<FunctionPrototype>(function.type.data).at(0));
             } break;
+            case NodeType::Return: {
+                try {
+                    memory.get_function_scope();
+                } catch (const InternalError& _) {
+                    throw RuntimeError(ErrorType::UnexpectedReturn, node.pos, {});
+                }
+                return {};
+            }
             default:
                 return {};
         }

src/errors.cpp

@@ -29,6 +29,7 @@ string UserError::get_message(void) const {
         case ErrorType::IncompatibleRedefinition: return "Redefinition of '"+get<string>(this->data)+"' as different kind of symbol";
         case ErrorType::IncompatibleDefinition: return "Declaration of '"+get<string>(this->data)+"' is incompatible with previous prototype";
         case ErrorType::UnexpectedArgumentCount: return "Expected "+to_string(get<int>(this->data))+" arguments to function call";
+        case ErrorType::UnexpectedReturn: return "Return not within a function";
         case ErrorType::ExpectedArithmeticType: return "Expression must have arithmetic type";
         case ErrorType::UnknownIdentifier: return "Unknown identifier '"+get<string>(this->data)+"'";
         case ErrorType::AlreadyDeclaredIdentifier: return "Already declared identifier '"+get<string>(this->data)+"'";

src/include/errors.h

@@ -38,6 +38,7 @@ enum class ErrorType {
     IncompatibleRedefinition, // redefinition of a variable as a function
     IncompatibleDefinition, // function declaration incompatible with prototype
     UnexpectedArgumentCount,
+    UnexpectedReturn,
 
     // Runtime
     UnknownIdentifier,