Definitions on Arrays

This file contains various definitions on Array. It does not contain proofs about these definitions, those are contained in other files in Batteries.Data.Array.

def Array.equalSet {α : Type u_1} [BEq α] (xs ys : Array α) : Bool

Check whether xs and ys are equal as sets, i.e. they contain the same elements when disregarding order and duplicates. O(n*m)! If your element type has an Ord instance, it is asymptotically more efficient to sort the two arrays, remove duplicates and then compare them elementwise.

@[inline]

def Array.minWith {α : Type u_1} [ord : Ord α] (xs : Array α) (d : α) (start : Nat := 0) (stop : Nat := xs.size) : α

Returns the first minimal element among d and elements of the array. If start and stop are given, only the subarray xs[start:stop] is considered (in addition to d).

@[inline]

def Array.minD {α : Type u_1} [ord : Ord α] (xs : Array α) (d : α) (start : Nat := 0) (stop : Nat := xs.size) : α

Find the first minimal element of an array. If the array is empty, d is returned. If start and stop are given, only the subarray xs[start:stop] is considered.

@[inline]

def Array.min? {α : Type u_1} [ord : Ord α] (xs : Array α) (start : Nat := 0) (stop : Nat := xs.size) : Option α

Find the first minimal element of an array. If the array is empty, none is returned. If start and stop are given, only the subarray xs[start:stop] is considered.

@[inline]

def Array.minI {α : Type u_1} [ord : Ord α] [Inhabited α] (xs : Array α) (start : Nat := 0) (stop : Nat := xs.size) : α

Find the first minimal element of an array. If the array is empty, default is returned. If start and stop are given, only the subarray xs[start:stop] is considered.

@[inline]

def Array.maxWith {α : Type u_1} [ord : Ord α] (xs : Array α) (d : α) (start : Nat := 0) (stop : Nat := xs.size) : α

Returns the first maximal element among d and elements of the array. If start and stop are given, only the subarray xs[start:stop] is considered (in addition to d).

@[inline]

def Array.maxD {α : Type u_1} [ord : Ord α] (xs : Array α) (d : α) (start : Nat := 0) (stop : Nat := xs.size) : α

Find the first maximal element of an array. If the array is empty, d is returned. If start and stop are given, only the subarray xs[start:stop] is considered.

@[inline]

def Array.max? {α : Type u_1} [ord : Ord α] (xs : Array α) (start : Nat := 0) (stop : Nat := xs.size) : Option α

Find the first maximal element of an array. If the array is empty, none is returned. If start and stop are given, only the subarray xs[start:stop] is considered.

@[inline]

def Array.maxI {α : Type u_1} [ord : Ord α] [Inhabited α] (xs : Array α) (start : Nat := 0) (stop : Nat := xs.size) : α

Find the first maximal element of an array. If the array is empty, default is returned. If start and stop are given, only the subarray xs[start:stop] is considered.

Safe Nat Indexed Array functions

The functions in this section offer variants of Array functions which use Nat indices instead of Fin indices. All these functions have as parameter a proof that the index is valid for the array. But this parameter has a default argument by get_elem_tactic which should prove the index bound.

@[reducible, inline]

abbrev Array.setN {α : Type u_1} (a : Array α) (i : Nat) (x : α) (h : i < a.size := by get_elem_tactic) : Array α

setN a i h x sets an element in a vector using a Nat index which is provably valid. A proof by get_elem_tactic is provided as a default argument for h. This will perform the update destructively provided that a has a reference count of 1 when called.

@[inline]

def Subarray.isEmpty {α : Type u_1} (as : Subarray α) : Bool

Check whether a subarray is empty.

@[inline]

def Subarray.contains {α : Type u_1} [BEq α] (as : Subarray α) (a : α) : Bool

Check whether a subarray contains an element.

def Subarray.popHead? {α : Type u_1} (as : Subarray α) : Option (α × Subarray α)

Remove the first element of a subarray. Returns the element and the remaining subarray, or none if the subarray is empty.