Add Tarjan SCC algorithm implementation #332
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Created using spr 1.3.5
yamadapc
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Feb 6, 2025
Adds an implementation of Tarjan's algorithm to find strongly connected components. This will be used on the experimental bundler to simplify cycle handling and can be used on other parts of the codebase to simplify the symbol propagation implementation. On the bundler, we will use this to convert the graph to an acyclic graph (replace the strongly connected components with a single 'group' node) before doing other work. Test Plan: yarn test Pull Request: #332
yamadapc
added a commit
that referenced
this pull request
Feb 6, 2025
Adds an implementation of Tarjan's algorithm to find strongly connected components. This will be used on the experimental bundler to simplify cycle handling and can be used on other parts of the codebase to simplify the symbol propagation implementation. On the bundler, we will use this to convert the graph to an acyclic graph (replace the strongly connected components with a single 'group' node) before doing other work. Test Plan: yarn test Pull Request: #332
JakeLane
approved these changes
Feb 7, 2025
| * Time complexity: O(V + E) | ||
| * Space complexity (worst case): O(V) | ||
| * | ||
| * * https://web.archive.org/web/20170829214726id_/http://www.cs.ucsb.edu/~gilbert/cs240a/old/cs240aSpr2011/slides/TarjanDFS.pdf |
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This is a great precedent to set 💯. I'm often getting confused what the underlying algorithms in this repo are
| const result = []; | ||
| let index = 0; | ||
| const stack = []; | ||
| const state: State[] = new Array(graph.nodes.length).fill(null).map(() => ({ |
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fill isn't necessary?
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It's necessary because the array returned from new Array(length) will be sparse https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Indexed_collections#sparse_arrays
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Ah right, I was mixing it up with this syntax which is a bit more succinct
Array.from({ length: 10 }, () => ({
index: null,
lowlink: null,
onStack: false,
}))
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Adds an implementation of Tarjan's algorithm to find strongly connected
components.
This will be used on the experimental bundler to simplify cycle handling and
can be used on other parts of the codebase to simplify the symbol propagation
implementation.
On the bundler, we will use this to convert the graph to an acyclic graph
(replace the strongly connected components with a single 'group' node) before
doing other work.
Test Plan: yarn test