1 files changed, 29 insertions, 0 deletions
diff --git a/myfind/ast_evaluation/ast_evaluation.c b/myfind/ast_evaluation/ast_evaluation.c
new file mode 100644
index 0000000..7ad91af
--- /dev/null
+++ b/myfind/ast_evaluation/ast_evaluation.c
@@ -0,0 +1,29 @@
+#include <err.h>
+#include <stdio.h>
+
+#include "expression.h"
+
+int eval_expr(struct my_expr *expr)
+{
+    if (expr->type == EXPR_NUMBER)
+        return expr->data.value;
+    else if (expr->type == EXPR_NEGATION)
+        return -1 * eval_expr(expr->data.children.left);
+    else
+    {
+        int right = eval_expr(expr->data.children.right);
+        switch (expr->type)
+        {
+        case EXPR_ADDITION:
+            return eval_expr(expr->data.children.left) + right;
+        case EXPR_SUBTRACTION:
+            return eval_expr(expr->data.children.left) - right;
+        case EXPR_MULTIPLICATION:
+            return eval_expr(expr->data.children.left) * right;
+        default:
+            if (expr->data.children.right == NULL || (right == 0))
+                err(1, "Division by zero not allowed!");
+            return eval_expr(expr->data.children.left) / right;
+        }
+    }
+}