rework syntax checks, rework priority correction algorithm

src/main.cpp

@@ -10,15 +10,11 @@ int main(int argc, char **argv)
 
 	std::vector<Expression::Token> tv = Parser::tokenize_input(argv[1]);
 
-	Syntax::pre_process(tv);
-
-	if (Syntax::check_syntax(tv))
+	if (Syntax::prepare_token_vector(tv))
 	{
 		return 0;
 	}
 
-	Syntax::post_process(tv);
-
 	std::vector<Expression::Operation> ov = Syntax::build_op_vector(tv);
 
 	Expression::TreeNode root = Syntax::ov_to_tree(tv, ov);

src/test-cases.cpp

@@ -99,7 +99,10 @@ TEST(tree_proper_test_1)
 TEST(tree_proper_test_2)
 {
 	std::vector<Expression::Token> o = Parser::tokenize_input("(1**5 * (1-2-3-4-5-6-7-8))");
-	Syntax::post_process(o);
+	if (Syntax::prepare_token_vector(o))
+	{
+		return 1;
+	}
 	std::vector<Expression::Operation> ov = Syntax::build_op_vector(o);
 
 	return 0;