variant to record

[bobzhang]

• no Blk_na
• offending primitives:
  Obj.new_block, Obj.field, Obj.set_field, Obj.size, Obj.truncate
• Blk_lazy
• Oo.id/object_tag
  For ocaml objects, it is so dynamic that we have to compile it into array, _n indexing won't work since its size is created dynamically, we have to make sure for such field access is also compiled into array access

[sgrove]

Will this also cover polymorphic variants? Specifically, I'm trying to bind to some complex JS components that need them:

module Column = {
    [@bs.deriving abstract]
    type props = {
      [@bs.optional]
      align: [@bs.string] [ | `left | `right | `center],
    };
  }
}

But

align: [@bs.string] [ | `left | `right | `center]

doesn't work, which means writing a bunch of wrappers back and forth. Compiling flat polymorphic variants to strings (and respecting [@bs.as]) would make these much more ergonomic to use and lightweight at runtime.

[TheSpyder]

@sgrove AFAIK this is based on #3801 which is only for non-polymorphic variants. A separate ticket (#4295) was opened last week regarding poly variant representation

[bobzhang]

done in master