Welcome to pyrsistent-extras’s documentation!¶
Pyrsistent-Extras¶
Extra data structures for pyrsistent
Below are examples of common usage patterns for some of the structures and features. More information and full documentation for all data structures is available in the documentation.
PSequence¶
Persistent sequences implemented with finger trees, with \(O(\log{n})\) merge/split/lookup and \(O(1)\) access at both ends.
>>> from pyrsistent_extras import psequence
>>> seq1 = psequence([1, 2, 3])
>>> seq1
psequence([1, 2, 3])
>>> seq2 = seq1.append(4)
>>> seq2
psequence([1, 2, 3, 4])
>>> seq3 = seq1 + seq2
>>> seq3
psequence([1, 2, 3, 1, 2, 3, 4])
>>> seq1
psequence([1, 2, 3])
>>> seq3[3]
1
>>> seq3[2:5]
psequence([3, 1, 2])
>>> seq1.set(1, 99)
psequence([1, 99, 3])
PHeap¶
Persistent heaps implemented with binomial heaps,
with \(O(1)\) findMin/insert and \(O(\log{n})\) merge/deleteMin.
Comes in two flavors: PMinHeap and PMaxHeap.
>>> from pyrsistent_extras import pminheap
>>> heap1 = pminheap([(1,'a'), (2,'b')])
>>> heap1
pminheap([(1, 'a'), (2, 'b')])
>>> heap2 = heap1.push(3,'c')
>>> heap2
pminheap([(1, 'a'), (2, 'b'), (3, 'c')])
>>> heap3 = heap1 + heap2
>>> heap3
pminheap([(1, 'a'), (1, 'a'), (2, 'b'), (2, 'b'), (3, 'c')])
>>> key, value, heap4 = heap3.pop()
>>> (key, value)
(1, 'a')
>>> heap4
pminheap([(1, 'a'), (2, 'b'), (2, 'b'), (3, 'c')])
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