Don't require "nested" indentation for multiline formulas?

[ThomasSoeiro]

First, thank you for this very useful package!

Is the following lint intended?

txt <- "
y ~
  var_1 +
  var_2 +
  var_3
"
lintr::lint(
  txt,
  linters = lintr::linters_with_defaults(),
  parse_settings = FALSE
)
#> <text>:4:2: style: [indentation_linter] Indentation should be 4 spaces but is 2 spaces.
#>   var_2 +
#>  ^~~

lintr currently expects a "nested" indentation:

txt <- "
y ~
  var_1 +
    var_2 +
    var_3
"
lintr::lint(
  txt,
  linters = lintr::linters_with_defaults(),
  parse_settings = FALSE
)
#> ℹ No lints found.

I think it is suboptimal because there is no "hierarchy" between the variables.

FWIW, there have been similar discussions for air here: posit-dev/air#444.

[MichaelChirico]

See also #2007, #2960, and tidyverse/style#197.

As I see it, 2 indendations is correct:

• Indentation 1 is for the LHS and RHS of the formula

• Indentation 2 is how any arithmetic expression is indented:

  x +
    y
  if (TRUE) {
    x +
      y
  }

So I do think it's WAI, though possibly something to be parameterized.

[ThomasSoeiro]

FWIW, here are some multiline formulas formatted with Air:

y ~
  var_1 +
  var_2 +
  var_3

x <-
  y ~
    var_1 +
    var_2 +
    var_3

x <- y ~
  var_1 +
  var_2 +
  var_3