Force Vim to align params in Lisp

Question

I am in a computer science class that requires that Lisp style look like this:

(define append (as bs)
  (if (null? as)
      bs
      (cons (car as)
            (append (cdr as) bs))))

instead of like this:

(define append (as bs)
  (if (null? as)
    bs
    (cons (car as)
          (append (cdr as) bs))))

Namely, the if branches should be aligned. Is there a way to force Vim to do this?

Not really helpful if you really want to use vim, but the example you gave is formatted as you wish with the Scheme mode of Emacs (with default configuration). — coredump, Sep 26 '16 at 15:18
https://www.reddit.com/r/programming/comments/1cij7/ask_reddit_best_way_to_edit_scheme_in_vim/ — coredump, Sep 26 '16 at 15:21
@coredump thank you but I do not need fancy features like that -- just different indentation. — tekknolagi, Sep 26 '16 at 15:39
@coredump that seems like the reverse; I want it to change the behavior of current lispwords. — tekknolagi, Sep 26 '16 at 16:07
That's a rather strange requirement from your course, considering that the not aligned branches are "standard" (at least for Common Lisp and AFAIK) — Daniel Jour, Sep 26 '16 at 16:41
@DanielJour I'll go back and check the requirements specifically but I think that is the case. — tekknolagi, Sep 26 '16 at 20:26

score 2 · Answer 1 · answered Apr 17 '17 at 17:32

If you want Vim's Lisp mode to treat all forms as function calls, so that items of a multi-line expression align with the second element, then simply clear the lispwords parameter:

:set lispwords=

From your exmaple, you do seem to want a split define to be treated with indentation rather than alignment. Figure out the set of forms for which you want indenting rather than aligning behavior and put that exact set into your lispwords:

:set lispwords=define[,... whatever other symbols]

This can be done based on file type with an auto-loaded. In your .vimrc file you can have:

:au BufRead,BufNewFile *.scm set lispwords=define

After putting that in my .vimrc temporarily, if I edit a new file:

$ vim foo.scm

and then insert a few lines, they get automatically formatted like thisL

(define fun ()
  (if foo
      (then ...)
      (else ...)
~
~
~
:q!

I just hit Enter there; the auto-indentation kicked in. Vim's config already associates .scm files with Scheme and sets up Lisp mode. Our au command customizes that by overriding lispwords.

Force Vim to align params in Lisp

1 Answers1