Formatting of error messages

[krlmlr]

rlang::as_function(list())
#> Error: Cannot convert objects of type `list` to `function`

Types should not be quoted: tidyverse/dplyr#2448 (comment).

[hadley]

Maybe should be Can't covert a list to a function?

[krlmlr]

I wonder how much of error.R in tidyverse/dplyr#2608 can actually move to rlang.

[lionel-]

the advantage of quoting is that you don't have to deal with grammar. E.g. this would be weird: Cannot convert a environment to a integer.

[hadley]

@lionel- we could fix that with friendly_type_of(x, article = TRUE). Or even dropping the articles would be fine: Can't convert list to integer vector