If performance is an issue, regular expressions are likely to be too slow
to begin with. But you could always do this to count the number of lines in
a particular string:
```js
var count = 0
var re = /\n|\r\n?/g
while (re.test(str)) count++
console.log(count)
```
Given it's already this easy to iterate something with a regexp, I'm not
convinced it's necessary to add this property/method.
On Sat, Jan 12, 2019 at 17:29 kai zhu <kaizhu...@gmail.com> wrote:
> a common use-case i have is counting newlines in largish (> 200kb)
> embedded-js files, like this real-world example [1]. ultimately meant for
> line-number-preservation purposes in auto-lint/auto-prettify tasks (which
> have been getting slower due to complexity).
>
> would a new RegExp count-method like ```(/\n/g).count(largeCode)``` be
> significantly more efficient than existing ```largeCode.split("\n").length
> - 1``` or ```largeCode.replace((/[^\n]+/g), "").length```?
>
> -kai
>
> [1] calculating and reproducing line-number offsets when
> linting/autofixing files
>
> https://github.com/kaizhu256/node-utility2/blob/2018.12.30/lib.jslint.js#L7377
>
> https://github.com/kaizhu256/node-utility2/blob/2018.12.30/lib.jslint.js#L7586
>
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