lifo¶

class pythonic_fp.queues.lifo.LIFOQueue¶

Bases: Generic

LIFOQueue

Stateful Last-In-First-Out (LIFO) Queue data structure.

O(1) pops
O(1) amortized pushes
O(1) length determination
in a Boolean context, true if not empty, false if empty
will automatically increase storage capacity when needed
neither indexable nor sliceable by design

__init__(*ds: Iterable) → None¶

Initializer

Initialize LIFOQueue with 0 or 1 iterables to populate the queue in natural LIFO order.

Parameters:

ds – Takes 0 or 1 iterable parameters.

Raises:

ValueError – When more than one parameter is provided.
TypeError – When passed a non-iterable parameter.

__bool__() → bool¶: Truthiness

LIFOQueue truthy when non-empty, falsy when empty.

__len__() → int¶: Get length

Return the number of data elements in the LIFOQueue.

__eq__(other: object) → bool¶

Equality comparison

If other is a LIFOQueue and the corresponding elements of self and other compare as equal, then return True. Otherwise return False.

Returns:: self == other

__iter__() → Iterator¶

Iteration

Iterate over current state in natural LIFO order.

Returns:: Iterator of the data.

__repr__() → str¶

String representation

Construct string ‘LIFOQueue(d₁, d₂, … dₙ)’ where

d₁, d₂, … dₙ are the contents displayed with repr()

Returns:: A string to reproduce the LIFOQueue.

__str__() → str¶

User string

Construct string ‘|| d₁ > d₂ > … > dₙ ><’ where

d₁, d₂, …, dₙ are the contents displayed with str()

Returns:: A string meaningful to an end user.

copy() → LIFOQueue[D]¶

Copy

Shallow copy the LIFOQueue.

Returns:: New LIFOQueue instance containing the same references.

push(*ds: D) → None¶

Push

Push items onto LIFOQueue.

Parameters:: ds – Items to be pushed onto LIFOQueue.

pop() → MayBe¶

Pop

Pop newest data item off of LIFOQueue.

Returns:: MayBe of popped data item if LIFOQueue was not empty, empty MayBe otherwise.

peak() → MayBe¶

Peak last

Peak at newest item on LIFOQueue.

Returns:: MayBe of newest item on queue, empty MayBe if queue empty.

fold(f: Callable[[D, D], D]) → MayBe[D]¶

fold(f: Callable[[T, D], T], start: T) → MayBe[T]

Fold

Reduces LIFOQUEUE in natural LIFO Order, newest to oldest.

Parameters:

f – Reducing function, first argument is for accumulator.
start – Optional starting value.

Returns:

MayBe of reduced value with f, empty MayBe if LIFOQueue empty and no starting value given.

map(f: Callable[[D], U]) → LIFOQueue¶

Map

Map f over the LIFOQueue, retain original order.

Parameters:: f – Function to map over LIFOQueue.
Returns:: New LIFOQueue instance.

pythonic_fp.queues.lifo.lifo_queue(*ds: D) → LIFOQueue¶

Create LIFOQueue

Factory function to create an LIFOQUEUE instance from the function’s arguments.

Parameters:: ds – Items pushed onto queue in LIFO order.
Returns:: New LIFOQueue instance.