expr VS goawk

Not diminishing the article at all, there's massive value I've gained from leveraging this runtime solution in multiple projects: https://github.com/antonmedv/expr

The language is easy enough for people to pick-up.

Uses the [expr](https://github.com/antonmedv/expr) language to achieve this and I've been super happy with the results.

I have been using expr (https://github.com/antonmedv/expr) to do something like this for a while. no complains so far.

If you wanted it to not require putting in the operation first and just accept string equations (without using something like https://github.com/antonmedv/expr) you could parse, tokenize and then process the input.

TIL: GoAWK [1] - A POSIX-compliant AWK interpreter written in Go, with CSV support.

[1]: https://github.com/benhoyt/goawk

Another nice project that I have used from time to time (and a very good source for insight) is the awk interpreter written in go https://github.com/benhoyt/goawk

No, I want exactly the opposite - it should be a , b,c as a single string field containing a literal comma, and c. For example, https://github.com/benhoyt/goawk has csv support. https://github.com/benhoyt/goawk/blob/master/docs/csv.md - more info.

I've had a go at solving this in this PR -- feedback welcome. I don't love it, but oh well, it solves the problem at hand. Your comment pointed me in the right direction, thanks again.

There are quite a few re-implementations of scripting languages like Lua in Go. I've written an AWK interpreter in Go.

github.com/benhoyt/goawk -> this library lets you embed an AWK runtime in your applications, very easy to use and useful for enabling some powerful scripting in things you build

Yes, that's right. With my simplistic UTF-8-based implementation it turned length() -- for example -- from O(1) to O(N), turning O(N) algorithms which use length() into O(N^2). See this issue: https://github.com/benhoyt/goawk/issues/93

Similar with substr() and other string functions, which when operating as bytes are O(1), but become O(N) when trying to count the number of codepoints as UTF-8.

GNU Gawk has a fancier approach, which stores strings as UTF-8 as long as it can, but converts to UTF-32 if it needs to (eg: the string is non-ASCII and you call substr).

It looks like Brian Kernighan's code has the same issue with length() and substr(). I'm going to try to email him about this, as I think it's kind of a performance blocker.

I'm not sure if it was via my personal website or just my GitHub profile, but I got my current job at Canonical due to the CTO there reaching out about my GoAWK project (https://github.com/benhoyt/goawk). I get regular recruitment emails because I have my CV/resume online: most of them are very low-effort, but 1 in 20 or something are interesting emails where the recruiter has actually looked at my website and will tailor it personally. I also just enjoy technical writing, and get joy out of sharing it on HN. So it's "worth it" for me.