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@@ -147,19 +147,20 @@ File | Description ## Performance -Currently, `bp` is super slow compared to hyper-optimized regex tools like -`grep` and `ripgrep`. `bp` is **not** matching regular expressions, so this is -not strictly a fair comparison. By definition, regular expressions can be -implemented using finite state machines, which are very efficient. Most regex -tools also add the additional restriction that matches must be within a single -line. `bp` on the other hand, uses parsing expression grammars, which can match -arbitrarily complicated or nested structures, requiring a dynamic call stack -and potentially unbounded memory use. This makes `bp` patterns much more -expressive, but harder to optimize. At this point in time, `bp`'s -implementation also uses a fairly naive virtual machine written in C, which is -not very heavily optimized. As a result, `bp` runs quite fast over thousands of -lines of code, reasonably fast over tens of thousands of lines of code, and -pretty slow over millions of lines of code. +Currently, `bp`'s speed is comparable to hyper-optimized regex tools like +`grep`, `ag`, and `ripgrep` when it comes to simple patterns that begin with +string literals, but `bp`'s performance may be noticeably slower for complex +patterns on large quantities of text. The aforementioned regular expression +tools are usually implemented as efficient finite state machines, but `bp` is +more expressive and capable of matching arbitrarily nested patterns, which +precludes the possibility of using a finite state machine. Instead, `bp` uses a +fairly simple recursive virtual machine implementation with memoization. `bp` +also has a decent amount of overhead because of the metadata used for +visualizing and explaining pattern matches, as well as performing string +replacements. Overall, I would say that `bp` is a great drop-in replacement for +common shell scripting tasks, but you may want to keep the other tools around +in case you have to search through a truly massive codebase for something +complex. ## License |