Lionel Henry

`eval_tidy()` with `...` in two-sided formula

2

```r rlang::eval_tidy(... ~ 1) #> Error in rlang::eval_tidy(... ~ 1) : '...' used in an incorrect context rlang::eval_tidy(1 ~ ...) Error in rlang::eval_tidy(1 ~ ...) : '...' used in an...

We could replace formulas by `rlang::q(expr, )` calls (or `rlang::q(expr)` if we store the env in attributes like with formulas, but I like @brodieG's idea of leaving it apparent in...

See https://github.com/tidyverse/purrr/issues/749.

dots_n() should take into account splicing

3

And return `NA` if it detects splicing?

Linked to https://github.com/r-lib/rlang/issues/906 for `!!!` arguments. ```r fn hop #> hop ```

To avoid repeated side effects when an argument is defused multiple times: ```r my_function % summarise("{{ what }}" := mean({{ what }})) } ```

API for events and hooks

2

- task callbacks - hooks and events - deferred expressions (exits) Needs to wrap 4 actions: append, prepend, replace, get. Appending and prepending might be handled with `push_` prefixed verbs...

Escape non-method members with `I()`

4

So these would be equivalent: ```r R6::R6Class("class", public = list( x = I(my_function) ) ) R6::R6Class("class", public = list( initialize = function() self$x = my_function, x = NULL ) )...

Signal exhaustion of top-level callbacks with a user prompt

5

Code running at top-level might cause new output: ```r later::later(~ message("foo"), 1) ``` ``` > foo ``` Or: ```r later::later(~ stop("foo"), 1) ``` ``` > later: exception occurred while executing...

Implement `compose()` lazily

1

So we could use `compose()` to create function operators like `possibly()`, `safely()`, etc. It would generate this call: ```r `_fn3`(`_fn2`(`_fn1`(...))) ``` Also allow custom names (automatically prefixed with `_`) in...