SE-0354 (Second Review): Regex Literals

[ensan-hcl (ensan)]

Ah sorry. This comment in pitch thread was in my mind.

@hamishknight

The problem with #regex("...") is that it looks like a string literal argument to a magic literal, when in fact the quotes are part of the delimiter itself. For example, you wouldn't be able to do:

let pattern = "[abc]+"
let regex = #regex(pattern)

which would likely be unexpected.

@hamishknight

Note it wouldn't be entirely like StaticString (or literals in general), as you also wouldn't be able to intermix any expressions between #regex(...) and the "..." argument. For example you wouldn't be able to write:

#regex(b ? "[abc]" : "[def]")

Or, if you were, it would lose out on editor support.

As the counter argument for #regex("..."), he pointed out that the ("...") part behaves differently compared to other functions, since it does not allow expressions like #regex(x) or even #regex(condition ? "abc" : "def").

However, proposed @const parameters can support such behavior. Therefore, if they are introduced, #regex("...") signature is less unfamiliar, because the behavior is very similar to @const parameters.

I also understand #regex("") alternative has other problems as written in the proposal. I suggest nothing here, but I was just curious about how the SE-0359 relates to this proposal.