python3-pyrsistent - 0.20.0-1+b4 main

Pyrsistent is a number of persistent collections (sometimes referred
to as functional data structures). Persistent in the sense that they
are immutable.
.
All methods on a data structure that would normally mutate it instead
return a new copy of the structure containing the requested updates.
The original structure is left untouched.
.
The collection types and key features currently implemented are:
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* PVector, similar to a python list
* PMap, similar to dict
* PSet, similar to set
* PRecord, a PMap on steroids with fixed fields, optional type and
invariant checking and much more
* PClass, a Python class fixed fields, optional type and invariant
checking and much more
* Checked collections, PVector, PMap and PSet with optional type
and invariance checks and more
* PBag, similar to collections.Counter
* PList, a classic singly linked list
* PDeque, similar to collections.deque
* Immutable object type (immutable) built on the named tuple
* freeze and thaw functions to convert between pythons standard
collections and pyrsistent collections.
* Flexible transformations of arbitrarily complex structures built
from PMaps and PVectors.