this isn’t just an academic curiosity. flip the alternation order to (ab|a)+ and suddenly PCRE matches the entire string! the | operator in backtracking engines is ordered - it’s not union, it’s “try left first”. the order of branches changes the result, which means | is not commutative. a|b and b|a can give different matches.
No one is formally verifying the result.
。关于这个话题，im钱包官方下载提供了深入分析
parent.consume();
Crash regression for state machine conflicts: A test specifically checks that calling byobRequest.respond() after enqueue() doesn't crash the runtime. This sequence creates a conflict in the internal state machine — the enqueue() fulfills the pending read and should invalidate the byobRequest, but implementations must gracefully handle the subsequent respond() rather than corrupting memory in order to cover the very likely possibility that developers are not using the complex API correctly.
本次的年度征文设题很巧妙，体现了现代科技与传统人力对决的意思。