src/lib.rs

@@ -9,6 +9,7 @@ pub fn lint_code(code: &&str) -> Result<(), Vec<String>> {
 
     let mut loop_stack: Vec<usize> = vec![];
     let mut pos = 0 as usize;
+    let mut pointer = 0;
 
     let chars = code.chars().collect::<Vec<char>>();
     let size = code.len();
@@ -23,6 +24,20 @@ pub fn lint_code(code: &&str) -> Result<(), Vec<String>> {
         let char = chars[pos];
         pos += 1;
 
+        if char == '<' {
+            if pointer == 0 {
+                errors.push(format!("ERR: Reducing pointer to less than 0 is not allowed ({})", pos));
+                continue
+            }
+            pointer -= 1;
+        }
+        if char == '>' {
+            if pointer == 29999 {
+                errors.push(format!("ERR: Increasing pointer to more than 29999 is not allowed ({})", pos));
+                continue
+            }
+            pointer += 1;
+        }
         if char == '[' {
             loop_stack.push(pos);
             continue
@@ -75,7 +90,7 @@ pub fn eval_mem(bf_str: &&str, mem: &mut [u8], pointer: &mut usize) -> Result<()
         }
         if char == '<' {
             if *pointer == 0 {
-                return Err(format!("Attempt to reduce pointer to less than 0 ({})", pos));
+                return Err(format!("Attempt to reduce pointer to less than 1 ({})", pos));
             }
             *pointer -= 1;
             continue