structure Batteries.DList (α : Type u) : Type u

A difference List is a Function that, given a List, returns the original contents of the difference List prepended to the given List. This structure supports O(1) append and push operations on lists, making it useful for append-heavy uses such as logging and pretty printing.

• apply : List α → List α

  "Run" a DList by appending it on the right by a List α to get another List α.

• invariant (l : List α) : self.apply l = self.apply [] ++ l

  The apply function of a DList is completely determined by the list apply [].

def Batteries.DList.ofList {α : Type u} (l : List α) : DList α

O(1) (apply is O(|l|)). Convert a List α into a DList α.

def Batteries.DList.empty {α : Type u} : DList α

O(1) (apply is O(1)). Return an empty DList α.

instance Batteries.DList.instEmptyCollection {α : Type u} : EmptyCollection (DList α)

instance Batteries.DList.instInhabited {α : Type u} : Inhabited (DList α)

def Batteries.DList.toList {α : Type u} : DList α → List α

O(apply()). Convert a DList α into a List α by running the apply function.

def Batteries.DList.singleton {α : Type u} (a : α) : DList α

O(1) (apply is O(1)). A DList α corresponding to the list [a].

def Batteries.DList.cons {α : Type u} : α → DList α → DList α

O(1) (apply is O(1)). Prepend a on a DList α.

def Batteries.DList.append {α : Type u} : DList α → DList α → DList α

O(1) (apply is O(1)). Append two DList α.

def Batteries.DList.push {α : Type u} : DList α → α → DList α

O(1) (apply is O(1)). Append an element at the end of a DList α.

instance Batteries.DList.instAppend {α : Type u} : Append (DList α)

def Batteries.DList.ofThunk {α : Type u} (l : Thunk (List α)) : DList α

Convert a lazily-evaluated List to a DList

def Batteries.DList.join {α : Type u_1} : List (DList α) → DList α

Concatenates a list of difference lists to form a single difference list. Similar to List.join.