Show HN: Pypersistent – Functional Data Structures for Python
pypi.orgMy New Year's side project - a functional data structure library for Python, written in C++. Lock-free, immutable, quite fast. It was written with zero human edits. All Claude Code. The initial version (dictionary based on a Hash Array Mapped Trie) was done in 2 hours. The second version (5 data structures, including red-black-tree-based sorted map) took 46 commits over the last two weeks, done in between other things. Mostly a little prompt, enter, on to other things. Almost 10000 lines of code, 300 tests. CI, 3 platforms, publishing to pypi. Needless to say this would have taken me weeks a year ago. You can try it out here: https://colab.research.google.com/drive/1LWHEmvKZ-IS2raeg0RJ... One of the biggest relevations: Claude debugged like a human. Implementing the red-black tree yielded a lot of segfaults. It first tried to reason about the logic, couldn't find the bug. Then tried to run debuggers and stuff. This also went nowhere. I had to tell it to add printf statement to trace state changes, and write them to a file. This made finding the bug quite easy.