rework: Remove asserts and reduced lets

src/dllist.gleam

@@ -76,29 +76,30 @@ pub fn insert(list: DLList(a), val: a) -> DLList(a) {
       DLList(ref + 1, ref, dict.insert(list.mem, ref, node))
     }
     False -> {
-      let assert Ok(curr_node) = dict.get(list.mem, list.current)
-      let curr_node_2 = Node(..curr_node, right: ref)
+      let assert Ok(curr_node) = get_curr_node(list)
       let next = curr_node.right
 
       let next_node = case next == list.current {
-        True -> Ok(curr_node_2)
+        True -> Ok(Node(..curr_node, right: ref))
         False -> dict.get(list.mem, next)
       }
       let new_mem = case next == list.current {
         True -> list.mem
-        False -> dict.insert(list.mem, list.current, curr_node_2)
+        False ->
+          dict.insert(list.mem, list.current, Node(..curr_node, right: ref))
       }
       let new_mem = case next_node {
         Ok(next_node) -> {
-          let next_node_2 = Node(..next_node, left: ref)
-          dict.insert(new_mem, next, next_node_2)
+          dict.insert(new_mem, next, Node(..next_node, left: ref))
         }
         Error(_) -> new_mem
       }
-      let new_node = Node(val, list.current, next)
 
-      let new_mem = dict.insert(new_mem, ref, new_node)
-      DLList(list.counter + 1, list.counter, new_mem)
+      DLList(
+        counter: list.counter + 1,
+        current: list.counter,
+        mem: dict.insert(new_mem, ref, Node(val, list.current, next)),
+      )
     }
   }
 }
@@ -211,8 +212,10 @@ fn take_loop(list: DLList(a), n_times: Int, acc: List(a)) -> List(a) {
   case n_times {
     0 -> list.reverse(acc)
     n -> {
-      let assert Ok(item) = get(list)
-      take_loop(move_right(list), n - 1, [item, ..acc])
+      case get(list) {
+        Error(_) -> []
+        Ok(item) -> take_rev_loop(move_right(list), n - 1, [item, ..acc])
+      }
     }
   }
 }
@@ -226,8 +229,10 @@ fn take_rev_loop(list: DLList(a), n_times: Int, acc: List(a)) -> List(a) {
   case n_times {
     0 -> list.reverse(acc)
     n -> {
-      let assert Ok(item) = get(list)
-      take_rev_loop(move_left(list), n - 1, [item, ..acc])
+      case get(list) {
+        Error(_) -> []
+        Ok(item) -> take_rev_loop(move_left(list), n - 1, [item, ..acc])
+      }
     }
   }
 }
@@ -236,32 +241,43 @@ pub fn to_list(list: DLList(a)) -> List(a) {
   case is_empty(list) {
     True -> []
     False -> {
-      let assert Ok(a) = get(list)
-      [a, ..to_list_loop(list.current, do_move_right(list))]
+      case get(list) {
+        Error(_) -> []
+        Ok(val) -> [val, ..to_list_loop(do_move_right(list), list.current)]
+      }
     }
   }
 }
 
-fn to_list_loop(ref: Int, list: Result(DLList(a), Nil)) -> List(a) {
+fn to_list_loop(list: Result(DLList(a), Nil), start_ref: Int) -> List(a) {
   case list {
     Error(_) -> []
-    Ok(DLList(_, current, _)) if current == ref -> []
+    Ok(DLList(_, current, _)) if current == start_ref -> []
     Ok(list) -> {
-      let assert Ok(a) = get(list)
-      [a, ..to_list_loop(ref, do_move_right(list))]
+      case get(list) {
+        Error(_) -> []
+        Ok(val) -> [val, ..to_list_loop(do_move_right(list), start_ref)]
+      }
     }
   }
 }
 
 pub fn update(list: DLList(a), value: a) -> Result(DLList(a), Nil) {
   use <- bool.guard(when: is_empty(list), return: Error(Nil))
-  let assert Ok(curr_node) = get_curr_node(list)
-  Ok(
-    DLList(
-      ..list,
-      mem: dict.insert(list.mem, list.current, Node(..curr_node, val: value)),
-    ),
-  )
+  case get_curr_node(list) {
+    Error(_) -> Error(Nil)
+    Ok(curr_node) ->
+      Ok(
+        DLList(
+          ..list,
+          mem: dict.insert(
+            list.mem,
+            list.current,
+            Node(..curr_node, val: value),
+          ),
+        ),
+      )
+  }
 }
 
 fn update_dict_entry(