DhyeyMavani2003 / chipfiring / 33744530718

95%

main: 95%

Build Type

Pull #37

github

Committed by claude

Commit Message

fix: stop algorithms from mutating caller-owned divisors

Dhar's algorithm (and GonalityDharAlgorithm) wrapped the divisor passed
to its constructor by reference, so run(), send_debt_to_q(),
legal_set_fire() and get_maximal_legal_firing_set() rewrote the caller's
divisor in place. The algorithm now works on a private copy that shares
the caller's graph object and exposes it as configuration.divisor.

Related copy and identity fixes found by the same audit:

- Add CFDivisor.copy() (and __copy__) returning an independent divisor on
  the same CFGraph object, and use it in GreedyAlgorithm, CFConfig.copy
  and the EWD visualizer instead of copy.deepcopy / dict round trips,
  which silently replaced the graph object.
- Give CFGraph structural __eq__/__hash__ and delegate CFDivisor.__eq__
  and CFConfig._is_comparable_to to it, so linear_equivalence no longer
  rejects divisors on independently built or deserialized copies of the
  same graph.
- Make CFLaplacian.get_reduced_matrix a pure query; it inserted zero
  entries into the cached defaultdict rows on every read.
- Materialize the degrees argument in CFDivisor.__init__ so generators
  and zip objects no longer yield a silent zero divisor.
- Correct docstrings that advertised the mutation, document CFConfig's
  by-reference semantics, and update README, docs and CHANGELOG.
- Re-point two Dhar regression tests at the working divisor and add
  non-mutation, copy-semantics and graph-identity tests.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015nucXSJi5ruBENBYv2PNyS

Pull Request Pull Request #37: Stop algorithms from mutating caller-owned divisors; add CFDivisor.copy and structural graph equality

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263 of 263 new or added lines in 17 files covered. (100.0%)

12 existing lines in 1 file now uncovered.

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