Class inheriting from function generates invalid constructor

[hadley]

library(R7)

foo <- new_class("foo", class_function)
unclass(foo)
#> Error in print.default(x, useSource = useSource, ...): badly formed function expression

^{Created on 2022-08-08 by the reprex package (v2.0.1)}

[hadley]

It's weird that we're re-binding function here:

library(S7)

foo <- new_class("foo", class_function)
environment(foo)$`function`
#> function(.data = class_missing) {
#>     if (is_class_missing(.data)) {
#>       .data <- base_default(name)
#>     }
#>     .data
#>   }
#> <bytecode: 0x10cad7b58>
#> <environment: 0x10828f928>

^{Created on 2023-02-19 with reprex v2.0.2}

Oh that's because we're extending function — I wonder if that's the root of the problem.