diff --git a/src/include/parser.h b/src/include/parser.h
index 28049d3..d94c31a 100644
--- a/src/include/parser.h
+++ b/src/include/parser.h
@@ -89,7 +89,17 @@ struct ParseReturn {
 /**
  * Utilisé pour revenir en arrière quand quelque chose n'est pas reconnu
 */
-class ParseException : public std::exception {};
+class ParseException : public std::exception {
+    const char* what() const noexcept override {
+        return "Parse Exception";
+    }
+};
+
+class SyntaxError : public std::runtime_error {
+public:
+    explicit SyntaxError(const std::string& message)
+        : std::runtime_error(message) {}
+};
 
 /**
  * Parse a list of tokens and return the associated AST
diff --git a/src/main.cpp b/src/main.cpp
index 1b197b2..b6bd8c2 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1,23 +1,41 @@
+#include <string.h>
 #include <iostream>
 using namespace std;
 
 #include "include/input.h"
-#include "include/tokenize.h"
+#include "include/colors.h"
 #include "include/parser.h"
+#include "include/tokenize.h"
 #include "include/interpreter.h"
 
 int main(int argc, char* argv[]) {
+    bool print_ast = false;
+    int i=1;
+    while (i < argc) {
+        if (!strcmp(argv[i], "--show-ast") || !strcmp(argv[i], "-s")) {
+            print_ast = true;
+        } else {
+            cerr << "Unknow argument: " << argv[i] << endl;
+        }
+        i++;
+    }
+
     while (true) {
         try {
             string input = get_input();
             vector<Token> tokens = tokenize(input);
             Node ast = parse(tokens);
-            // _debug_print_tree(ast, 0, "");
+
+            if (print_ast)
+                _debug_print_tree(ast, 0, "");
+
             EvalResult res = eval(ast);
             cout << get<int>(res) << endl;
+        } catch (const SyntaxError& e) {
+            cout << RED "SyntaxError: " RESET << e.what() << endl;
+        } catch (const std::exception& e) { // temp
+            cout << RED "err: " RESET << e.what() << endl;
         }
-        catch (...) { // temp
-            cout << "err" << endl;
-        }
+        cout << endl;
     }
 }
\ No newline at end of file
diff --git a/src/parser.cpp b/src/parser.cpp
index ad35d0a..af03a9b 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -36,7 +36,7 @@ Node parse(vector<Token> tokens) {
     reverse(tokens.begin(), tokens.end());
 
     if (tokens.size() == 0)
-        throw ParseException();
+        throw SyntaxError("Input must not be empty");
         
 
     // At least 1 instruction
@@ -331,7 +331,7 @@ ParseReturn parse_f(vector<Token> tokens) {
             tokens=ret.tokens;
 
             if (tokens.size() < 1 || tokens.back().type != TokenType::RParenthese)
-                throw ParseException();
+                throw SyntaxError("Missing ')'");
 
             tokens.pop_back();