Potential alternative for flags syntax

[rauschma]

(Very useful library, thanks for creating it!)

Another option for specifying RegExp flags is:

regex`/^.+/gm`

That is equivalent to:

regex('gm')`^.+`

Benefits:

• Fewer characters to type.
• Syntax should be more familiar to programmers.
• Easier to switch between RegExp literals and tagged templates.

One could make the slashes optional if there are no flags.

[slevithan]

Thanks, @rauschma! 😊

I agree with the advantages you outlined. But there are also some disadvantages:

• Doesn’t match the RegExp constructor's syntax.
• Doesn’t match regex literal syntax either, since there are no multiline regex literals (and they're not planned for the future), plus literals don’t allow unescaped / outside of character classes.
• Flags-up-front is more readable IMO, particularly with long and/or multiline regexes. Since some flags affect the meaning of regex syntax, it helps to read the flags first. And the presence of flags is easier to miss when they're at the end.
• If you allow the convenience of taking the slashes off when not using flags, that also creates avoidable syntax ambiguity (e.g. when you want to start a pattern with a literal /).
• Probable incompatibility with any future standardized regex tag. There has been some discussion by/with TC39 about a standardized tagged template for regexes (perhaps RegExp.make('g')`.` or RegExp`(?g).`). Such discussions have not favored the `/.../g` format.

I'd prefer to avoid ambiguity and conflict between flags by not adding support for the `/.../flags` format on top of the current approach (flags as an argument). But it would be easy to add a user-side wrapper that drops flags as an argument and supports flags via the string. 😊

[rauschma]

• Makes sense!
• Independently of which approach is better, the library should indeed only support one syntax.

[rauschma]

(Aside: the content of your comment would make a great FAQ entry – it contains several interesting facts.)

[slevithan]

It took me a while, but per your suggestion, this is now covered by a new question in the FAQ.