Fast regex search: indexing text for agent tools
cursor.com22 points by jxmorris12 3 days ago
22 points by jxmorris12 3 days ago
I don't get grep in agentic settings for natural language queries. You want to optimize for best results with as few tokens/round trips as possible, not for speed.
> No matter how fast ripgrep can match on the contents of a file, it has one serious limitation: it needs to match on the contents of all files.
The omission of rg's `-g` parameter is unsurprising in one sense, because it would mostly obviate this entire exercise. How often do you need to search what sounds like hundreds of millions of lines of source for a complex pattern, with zero constraints on paths searched?
> We routinely see rg invocations that take more than 15 seconds
I'm trying to understand the monorepo that is so large that ripgrep takes 15 seconds to return results, when it's benchmarked as searching for a literal in a 9.3GB file in 600ms, or 1.08s to search for `.*` in the entire Linux repo.
And again, that's without using `-g`.
> -g GLOB, --glob=GLOB
> Include or exclude files and directories for searching that match the given glob. This always overrides any other ignore logic. Multiple glob flags may be used. Globbing rules match .gitignore globs. Precede a glob with a ! to exclude it. If multiple globs match a file or directory, the glob given later in the command line takes precedence. As an extension, globs support specifying alternatives: -g 'ab{c,d}*' is equivalent to -g abc -g abd. Empty alternatives like -g 'ab{,c}' are not currently supported. Note that this syntax extension is also currently enabled in gitignore files, even though this syntax isn't supported by git itself. ripgrep may disable this syntax extension in gitignore files, but it will always remain available via the -g/--glob flag.
> When this flag is set, every file and directory is applied to it to test for a match. For example, if you only want to search in a particular directory foo, then -g foo is incorrect because foo/bar does not match the glob foo. Instead, you should use -g 'foo/*'.
https://man.archlinux.org/man/rg.1.en*
(for those who were unfamiliar with the switch like me)
Has the Cursor team considered (for instance) that on MDM-managed machines, binaries which do pervasive arbitrary FS reads may be monitored, throttled, or otherwise controlled by overseer programs? That kitchen-sink Electron apps like Cursor using those binaries might compound the red-flag signals?
The creator of fff.nvim[0], Dmitriy Kovalenko, had an interesting analysis of this on Xitter[1]. The TL;DR of this is that Anysphere/Cursor is being somewhat disingenuous and does not include the index-creation and recreation time in the comparison nor do they include the CPU or memory overhead, where rg (and his tool, fff.nvim) are indexless.
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