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Summary of Changes
Hello @p14c31355, I'm Gemini Code Assist1! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!
This pull request focuses on improving code quality and consistency by applying automated formatting and linting tools. It standardizes code style and addresses minor issues identified by Clippy, making the codebase cleaner and easier to maintain without introducing new features or functional changes.
Highlights
- Code Formatting: Applied
cargo fmtto ensure consistent code style across the codebase. - Linting Fixes: Implemented automated fixes suggested by
cargo clippy --fixto address various lint warnings and improve code quality. - Code Modernization: Updated several loop constructs and
format_args!macro usages to more idiomatic Rust patterns, as suggested by Clippy.
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Code Review
This pull request applies automatic fixes from cargo clippy and cargo fmt. While most changes are beneficial formatting and idiomatic improvements, a critical bug has been introduced in the cycle detection logic within PermutationIter::new. An automated fix appears to have incorrectly removed a crucial part of Kahn's algorithm, which will lead to incorrect cycle detection. Additionally, the same function contains duplicated and confusing logic for cycle detection, with one block being buggy and seemingly dead code. I've left comments to address the critical bug and suggest refactoring the duplicated logic for improved maintainability.
| for v in 0..total_nodes { | ||
| if (adj_list_rev[u] >> v) & 1 != 0 { | ||
| temp_in_degree[v] -= 1; | ||
| if temp_in_degree[v] == 0 { | ||
| q.push(v as u8).map_err(|_| ExplorerError::BufferOverflow)?; | ||
| } | ||
| } | ||
| } |
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This change breaks the cycle detection logic (Kahn's algorithm). By removing the code that adds nodes with an in-degree of zero to the queue q, the algorithm will fail to traverse the entire graph if it has dependencies. This will cause it to incorrectly report a dependency cycle when one may not exist.
The logic to add nodes to the queue when their in-degree becomes zero should be restored.
| for v in 0..total_nodes { | |
| if (adj_list_rev[u] >> v) & 1 != 0 { | |
| temp_in_degree[v] -= 1; | |
| if temp_in_degree[v] == 0 { | |
| q.push(v as u8).map_err(|_| ExplorerError::BufferOverflow)?; | |
| } | |
| } | |
| } | |
| for v in 0..total_nodes { | |
| if (adj_list_rev[u] >> v) & 1 != 0 { | |
| temp_in_degree[v] -= 1; | |
| if temp_in_degree[v] == 0 { | |
| q.push(v as u8).map_err(|_| ExplorerError::BufferOverflow)?; | |
| } | |
| } | |
| } |
| } | ||
| } | ||
| for i in 0..total_nodes { | ||
| for (i, _) in temp_in_degree.iter().enumerate().take(total_nodes) { |
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This function PermutationIter::new appears to contain two separate and conflicting implementations for cycle detection using Kahn's algorithm.
-
The first block (lines 437-469) seems to be an incomplete or incorrect implementation. It attempts to use a
heapless::Vecas a C-style array with manual head/tail pointers, which will likely cause a panic at runtime because it writes to an empty vector out of bounds. It also doesn't use the_countvariable to check for a cycle. -
The second block (lines 470-492), which this change is part of, seems to be the intended implementation. However, as noted in another comment, this PR breaks its logic.
It is highly recommended to remove the first, buggy implementation (lines 437-469) and fix the second one to improve correctness and maintainability.
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