Changed evaluate function to free the memory it uses, temporary, will be changed to use a sigle arena for the tree

src/evaluator.c

@@ -1,22 +1,31 @@
 #include "evaluator.h"
 #include "lexer.h"
 #include <stdint.h>
+#include <stdlib.h>
 
 int64_t evaluate(ASTNode *tree) {
     if (tree->type == NODE_BINARY_OP) {
-        switch (tree->data.binary.op) {
+        Operator op = tree->data.binary.op;
+        ASTNode *left = tree->data.binary.left;
+        ASTNode *right = tree->data.binary.right;
+        
+        free(tree);
+
+        switch (op) {
             case OP_ADD:
-                return evaluate(tree->data.binary.left) + evaluate(tree->data.binary.right);
+                return evaluate(left) + evaluate(right);
             case OP_SUB:
-                return evaluate(tree->data.binary.left) - evaluate(tree->data.binary.right);
+                return evaluate(left) - evaluate(right);
             case OP_MUL:
-                return evaluate(tree->data.binary.left) * evaluate(tree->data.binary.right);
+                return evaluate(left) * evaluate(right);
             case OP_DIV:
-                return evaluate(tree->data.binary.left) / evaluate(tree->data.binary.right);
+                return evaluate(left) / evaluate(right);
 
         }
     } else {
-        return tree->data.integer;
+        int64_t return_val = tree->data.integer;
+        free(tree);
+        return return_val;
     }
 }