fix: split large epsilon fan-outs to avoid instruction size panic #278
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Summary
MAX_MATCH_PAYLOAD_SLOTSconstant (28) to bytecode moduleemit_epsilonto cascade large successor lists into multiple instructionsWhy
Tagged alternations with 27+ branches caused a panic at
ir.rs:302because theMatch64instruction can only hold 28 payload slots. The fix splits large fan-outs into a cascade of epsilon transitions, preserving NFA semantics.Reproducer:
Q = [A0: (id) @x0 A1: (id) @x1 ... A29: (id) @x29]