Can as_function() do better with primitive functions?

[hadley]

rlang::as_closure(seq.int)(1, 2)
#> Error in (rlang::as_closure(seq.int))(1, 2): argument "by" is missing, with no default

^{Created on 2022-08-27 by the reprex package (v2.0.1)}

[NikKrieger]

rlang::as_closure(seq.int) still does not produce the same results as seq.int:

seq.int(5)
#> [1] 1 2 3 4 5
rlang::as_closure(seq.int)(5)
#> [1] 5

seq.int(4:8)
#> [1] 1 2 3 4 5
rlang::as_closure(seq.int)(4:8)
#> Error in seq.int(from, to, ...): 'from' must be of length 1

seq.int("foo")
#> [1] 1
rlang::as_closure(seq.int)("foo")
#> Warning in (rlang::as_closure(seq.int))("foo"): NAs introduced by coercion
#> Error in seq.int(from, to, ...): 'from' must be a finite number

seq.int(letters)
#>  [1]  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
#> [26] 26
rlang::as_closure(seq.int)(letters)
#> Error in seq.int(from, to, ...): 'from' must be of length 1

^{Created on 2023-04-27 with reprex v2.0.2}

I see that seq.int receives special treatment in rlang:::op_as_closure(), but does it need special treatment?

Could you just change this line of rlang::as_closure()...

prim_call <- call2(x, !!!prim_args(fmls))

...to this?

prim_call <- expr({
  call <- sys.call()
  call[[1L]] <- !!x
  eval.parent(call)
})

This would ensure that the primitive only receives the arguments that its closure-wrapper received. Maybe there are performance implications I am naively unaware of with my suggestion.