fix(vm): make findAll linear by stopping matchAt when no threads remain

src/vm.zigmodified+11-0

Changes to src/vm.zig

		⋯226 linesShow the 226 lines above this hunk@@ -227,6 +227,17 @@ pub const VM = struct {
227	227	next_threads.clearRetainingCapacity();
228	228
229	229	pos += 1;
	230	+
	231	+ // No live threads remain. matchAt only ever seeds the start-state
	232	+ // thread (at start_pos), and threads can only be spawned by cloning
	233	+ // existing ones, so once the set is empty no further match can
	234	+ // begin from this start_pos — the longest match found so far
	235	+ // (last_match) is final. Without this break the loop walks every
	236	+ // remaining byte doing nothing; because findAll restarts matchAt
	237	+ // per match, that dead-walk is what makes findAll O(n^2). Any
	238	+ // accepting state reached on the consumed input was already
	239	+ // recorded by the accept check at the top of the loop.
	240	+ if (current_threads.items.len == 0) break;
230	241	}
231	242
232	243	// Return the last (longest) match we found