Weird error with `"\s"`

[lionel-]

Reported by @hadley

Evaluating "\s" in the console gives a weird error:

I traced it down to R_ParseVector() throwing an error instead of returning a syntax error code. This causes the control flow to end up in this safeguard path:

ark/crates/ark/src/interface.rs

Line 1335 in 452d00d

let status = unwrap!(harp::parse_status(&harp::ParseInput::Text(input)), Err(err) => {

.

[lionel-]

You'll see the same thing with 1 |> {}.

In general see https://github.com/r-devel/r-svn/blob/7da17dcbb20d1dfc901efd7dfee1623c21c925cf/src/main/gram.y#L4439 and https://github.com/r-devel/r-svn/blob/7da17dcbb20d1dfc901efd7dfee1623c21c925cf/src/main/gram.y#L4532 for the class of errors that can be thrown by the parser.

We should catch these classed R errors and convert them to proper syntax errors on the Rust side.

[DavisVaughan]

Why doesn't R_ParseVector() return an error code? Should we report that?

[lionel-]

I don't know but this seems intentional.