How to Format Magrittr Chains with ESS

Here is an example of how to format magrittr chains with ESS. Those interested will also be happy to learn of ess-R-fl-keyword:%op% and ess-%op%-face.

For example, to get the an indent after only the first statement.

(add-to-list 'ess-style-alist
               (ess-indent-level . 4)
               (ess-first-continued-statement-offset . 2)
               (ess-continued-statement-offset . 0)
               (ess-brace-offset . -4)
               (ess-expression-offset . 4)
               (ess-else-offset . 0)
               (ess-close-brace-offset . 0)
               (ess-brace-imaginary-offset . 0)
               (ess-continued-brace-offset . 0)
               (ess-arg-function-offset . 4)
           (ess-arg-function-offset-new-line . '(4))

(setq ess-default-style 'my-style)

Thank you Mr. Vitalie Spinu.


How I did it:

(setq gcr/ess-style
       (assoc 'RRR ess-style-alist)))
(setf (nth 0 gcr/ess-style) 'GCR)
(setf (cdr
       (assoc 'ess-continued-statement-offset
              (cdr gcr/ess-style)))
(add-to-list 'ess-style-alist gcr/ess-style)
(setq ess-default-style 'GCR)

Addendum: 2015-08-12

The latest version of ESS includes a RRR style.

It formats Magrittr chains as expected by default with ess-first-continued-statement-offset.

3 thoughts on “How to Format Magrittr Chains with ESS”

  1. I don’t suppose you also found a way to make comments which match the conventions of the R community, rather than that of Emacs lisp? Auto-indenting # right is a minor annoyance for both parties when trying to collaborate with people developing R outside of Emacs.

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