fix: updating arena and arraylist use

include/evaluator.h

@@ -7,6 +7,7 @@
 typedef enum {
     EVALUATOR_OK,
     EVALUATOR_MATH_ERR,
+    EVALUATOR_DIVISION_BY_ZERO,
     EVALUATOR_INVALID_PARSING,
     EVALUATOR_INVALID_TREE, // just to shut up the compiler with the swithces
 } EvaluatorErr;

include/parser.h

@@ -45,7 +45,7 @@ typedef struct {
     union {
         ParserErr err;
         struct {
-            Arena arena;
+            Arena *arena;
             Node *tree;
         };
     };