Allowing reserved words in polymorphic variants

1

I’m working on porting my websocket implementation from reason to rescript, and remembered how much this annoyed me:

@bs.send
external on: (
  t,
  @bs.string
  [
    | #close((int, string) => unit)
    | #message(string => unit)
    | @bs.as("open") #open_(unit => unit)
    | #ping(Node.Buffer.t => unit)
    | #pong(Node.Buffer.t => unit)
    | #error(Dom.errorEvent => unit)
  ],
) => t = "on"

Is there a reason that polymorphic variants can’t use reserved words, since afaik they’re always marked by a #? Or is it something that just hasn’t been deemed necessary.

2 Likes
2

Indeed I think that the parser should potentially be able to be disambiguate this. Since ReScript is now owning their own parser is this something that can be improved in the future?

3

You can write #\"open". See https://rescript-lang.org/docs/manual/latest/use-illegal-identifier-names for more context.

In the future we will support nicer syntax and allow reserved words without the escaping mechanism. But this will likely take a while.

7 Likes
4

Seeing as how you’d have to use the backslash at use site as well, this isn’t much better than just using #open_, unless I’m mistaken. Ah well.