Documentation

Std.Data.DList

structure Std.DList (α : 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 concat operations on lists, making it useful for append-heavy uses such as logging and pretty printing.

Instances For
def Std.DList.ofList {α : Type u} (l : List α) :

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

Equations
Instances For
    def Std.DList.empty {α : Type u} :

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

    Equations
    • Std.DList.empty = { apply := id, invariant := (_ : ∀ (x : List α), id x = id x) }
    Instances For
      Equations
      • Std.DList.instEmptyCollectionDList = { emptyCollection := Std.DList.empty }
      def Std.DList.toList {α : Type u} :
      Std.DList αList α

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

      Equations
      Instances For
        def Std.DList.singleton {α : Type u} (a : α) :

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

        Equations
        Instances For
          def Std.DList.cons {α : Type u} :
          αStd.DList αStd.DList α

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

          Equations
          • One or more equations did not get rendered due to their size.
          Instances For
            def Std.DList.append {α : Type u} :
            Std.DList αStd.DList αStd.DList α

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

            Equations
            • Std.DList.append x x = match x, x with | { apply := f, invariant := h₁ }, { apply := g, invariant := h₂ } => { apply := f g, invariant := (_ : ∀ (t : List α), f (g t) = f (g []) ++ t) }
            Instances For
              def Std.DList.push {α : Type u} :
              Std.DList ααStd.DList α

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

              Equations
              • Std.DList.push x x = match x, x with | { apply := f, invariant := h }, a => { apply := fun t => f (a :: t), invariant := (_ : ∀ (t : List α), f (a :: t) = f [a] ++ t) }
              Instances For
                Equations
                • Std.DList.instAppendDList = { append := Std.DList.append }