3 ms·

> The number of times I've used look-around or even back-references can be counted on one hand. I'm shocked. What do you most commonly use regexes for? For me,

> The number of times I've used look-around or even back-references can be counted on one hand. I'm shocked. What do you most commonly use regexes for? For me, I type them in my text editor find/replace more frequently than anything, and use backreferences there on a pretty regular basis.

burntsushi 3y ago
Yes, I use regexes in vim all the time. Never use look-around or really much regex features beyond the basics. 99% of all searches are easily just literals. I also use regexes with ripgrep of course. ripgrep has features that standard grep doesn't have that typically mitigate the need for look-around, such as the `-r/--replace` flag. (I can't remember I when I last used `-P/--pcre2` in ripgrep for a reason that wasn't testing it.) Otherwise the rest of my regex use is in programs for a variety of tasks. Note that I'm the author of Rust's regex crate and of this regex benchmark: https://github.com/BurntSushi/rebar https://github.com/BurntSushi/rebar
- dataflow 3y ago
  Yeah I know who you are, that's why I was shocked. That's why I'd have thought you leverage regexes more than other folks, not less! On my end I do this all the time. E.g., a very common regex search/replace I do over and over is something like removing duplicate lines, e.g. replacing "^(.*)\n\1\n" with "\1\n" repeatedly. (Obviously exact deduplication you can do a different way, but you can imagine variations on it that are case-specific, e.g. removing all lines or table fields that are prefixes of the following ones.) Of course I'm not claiming this is the majority of my searches (literals are obviously far more common like you said), but this kind of stuff comes up quite regularly, on perhaps a ~weekly basis if not more frequently. I'm very surprised you don't do transformations like these!
  - burntsushi 3y ago
    For that one in particular, nope. The only thing I can think of is when I'm trying to count occurrences of something, but that's just `sort | uniq -c`. I'll note that Discord also uses the regex crate for something to do with automod[1]. It would be interesting to ask their users how often they're annoyed by the lack of look-around or backreferences or some other fancy feature. Although in their case, the linear time guarantee is likely essential to exposing regex support in the first place. [1]: https://support.discord.com/hc/en-us/articles/10069840290711-Filter-Messages-Using-Regular-Expressions-Regex- https://support.discord.com/hc/en-us/articles/10069840290711...

burntsushi 3y ago

Yes, I use regexes in vim all the time. Never use look-around or really much regex features beyond the basics. 99% of all searches are easily just literals. I also use regexes with ripgrep of course. ripgrep has features that standard grep doesn't have that typically mitigate the need for look-around, such as the `-r/--replace` flag. (I can't remember I when I last used `-P/--pcre2` in ripgrep for a reason that wasn't testing it.) Otherwise the rest of my regex use is in programs for a variety of tasks. Note that I'm the author of Rust's regex crate and of this regex benchmark: https://github.com/BurntSushi/rebar https://github.com/BurntSushi/rebar

dataflow 3y ago
Yeah I know who you are, that's why I was shocked. That's why I'd have thought you leverage regexes more than other folks, not less! On my end I do this all the time. E.g., a very common regex search/replace I do over and over is something like removing duplicate lines, e.g. replacing "^(.*)\n\1\n" with "\1\n" repeatedly. (Obviously exact deduplication you can do a different way, but you can imagine variations on it that are case-specific, e.g. removing all lines or table fields that are prefixes of the following ones.) Of course I'm not claiming this is the majority of my searches (literals are obviously far more common like you said), but this kind of stuff comes up quite regularly, on perhaps a ~weekly basis if not more frequently. I'm very surprised you don't do transformations like these!
- burntsushi 3y ago
  For that one in particular, nope. The only thing I can think of is when I'm trying to count occurrences of something, but that's just `sort | uniq -c`. I'll note that Discord also uses the regex crate for something to do with automod[1]. It would be interesting to ask their users how often they're annoyed by the lack of look-around or backreferences or some other fancy feature. Although in their case, the linear time guarantee is likely essential to exposing regex support in the first place. [1]: https://support.discord.com/hc/en-us/articles/10069840290711-Filter-Messages-Using-Regular-Expressions-Regex- https://support.discord.com/hc/en-us/articles/10069840290711...