rsyntax

R >4.1 syntax: Error: function 'function' not supported in RHS call of a pipe

R 4.1.0 famously introduced the |> ("base pipe") operator and Haskell-like lambda function syntax.

I thought it would be possible to combine the two like this:

c(1, 2, 3) |> \(x) 2 * x

This fails for me with:

Error: function 'function' not supported in RHS call of a pipe

I thus assume this is not valid syntax? This works:

c(1, 2, 3) |> (\(x) 2 * x)()

Is there a more elegant way to chain the pipe and the new lambda functions?

Solution

  • I think the most elegant way is with curly braces:

    c(1, 2, 3) |> {\(x) 2 * x}()

    but this works too:

    c(1, 2, 3) |> (\(x) 2 * x)()

    The latter is recommended in ?`|>` :

    # or use an anonymous function:
mtcars |> subset(cyl == 4) |> (function(d) lm(mpg ~ disp, data = d))()
mtcars |> subset(cyl == 4) |> (\(d) lm(mpg ~ disp, data = d))()