Perf T3-5: Optimize BFS collect with typed Vector{Int}#145
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Characterization test verifying that manual BFS iteration (skipping self) produces identical follower lists to collect(BFSIterator(...))[2:end]. Tests both chain and branching graph topologies. Co-Authored-By: Claude Opus 4.6 <[email protected]>
Avoids intermediate allocation from collect() followed by array
slicing. The manual loop skips self directly and produces a
properly typed Vector{Int} instead of Vector{Any}.
Impact is negligible (per-player, first-iteration only, cached
thereafter) but eliminates unnecessary allocations.
Co-Authored-By: Claude Opus 4.6 <[email protected]>
Results show modest improvements:
- 1.0-1.5x speedup depending on graph size
- ~14% fewer allocations (avoids intermediate array + slice)
- Type stability: Vector{Any} -> Vector{Int64}
- Impact is negligible (per-player, first-iteration only, cached)
Co-Authored-By: Claude Opus 4.6 <[email protected]>
Co-Authored-By: Claude Opus 4.6 <[email protected]>
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Summary
Replace
collect(BFSIterator(graph, ii))[2:end]with manual iteration that producesVector{Int}instead ofVector{Any}. This improves type stability of the cached follower list.Note: The 11-15% allocation reduction applies only to the BFS collect micro-operation itself (e.g., 656B vs 576B), not to overall solver allocations. This code runs once per player and is then cached, so the impact on total allocations is negligible. The primary value is the type stability improvement (
Vector{Any}→Vector{Int}).Changes
src/nonlinear_kkt.jl: Replacecollect(BFSIterator(...))[2:end]with manual iteration producingVector{Int}test/: Add characterization tests verifying equivalence on chain and branching topologiesTesting
Changelog
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