10.5.3 Indentation

Standard GNU coding style is used.

Indenting files with fixcc.py (recommended)

LilyPond provides a python script that will adjust the indentation and spacing on a .cc or .hh file to very near the GNU standard:

scripts/auxiliar/fixcc.py FILENAME

This can be run on all files at once, but this is not recommended for normal contributors or developers.

scripts/auxiliar/fixcc.py \
  $(find flower lily -name '*cc' -o -name '*hh' | grep -v /out)

Indenting with emacs

The following hooks will produce indentation which is similar to our official indentation as produced with fixcc.py.

(add-hook 'c++-mode-hook
     '(lambda ()
        (c-set-style "gnu")
        (setq indent-tabs-mode nil))

If you like using font-lock, you can also add this to your ‘.emacs’:

(setq font-lock-maximum-decoration t)
(setq c++-font-lock-keywords-3
       '(("\\b\\(a-zA-Z_?+_\\)\\b" 1 font-lock-variable-name-face) ("\\b\\(A-Z?+a-z_?+\\)\\b" 1 font-lock-type-face))

Indenting with vim

Although emacs indentation is the GNU standard, acceptable indentation can usually be accomplished with vim. Some hints for vim are as follows:

A workable .vimrc:

set cindent
set smartindent
set autoindent
set expandtab
set softtabstop=2
set shiftwidth=2
filetype plugin indent on
set incsearch
set ignorecase smartcase
set hlsearch
set confirm
set statusline=%F%m%r%h%w\ %{&ff}\ %Y\ [ASCII=\%03.3b]\ [HEX=\%02.2B]\ %04l,%04v\ %p%%\ [LEN=%L]
set laststatus=2
set number
" Remove trailing whitespace on write
autocmd BufWritePre * :%s/\s\+$//e

With this ‘.vimrc’, files can be reindented automatically by highlighting the lines to be indented in visual mode (use V to enter visual mode) and pressing =.

A ‘scheme.vim’ file will help improve the indentation. This one was suggested by Patrick McCarty. It should be saved in ‘~/.vim/after/syntax/scheme.vim’.

" Additional Guile-specific 'forms'
syn keyword schemeSyntax define-public define*-public
syn keyword schemeSyntax define* lambda* let-keywords*
syn keyword schemeSyntax defmacro defmacro* define-macro
syn keyword schemeSyntax defmacro-public defmacro*-public
syn keyword schemeSyntax use-modules define-module
syn keyword schemeSyntax define-method define-class

" Additional LilyPond-specific 'forms'
syn keyword schemeSyntax define-markup-command define-markup-list-command
syn keyword schemeSyntax define-safe-public define-music-function
syn keyword schemeSyntax def-grace-function

" All of the above should influence indenting too
set lw+=define-public,define*-public
set lw+=define*,lambda*,let-keywords*
set lw+=defmacro,defmacro*,define-macro
set lw+=defmacro-public,defmacro*-public
set lw+=use-modules,define-module
set lw+=define-method,define-class
set lw+=define-markup-command,define-markup-list-command
set lw+=define-safe-public,define-music-function
set lw+=def-grace-function

" These forms should not influence indenting
set lw-=if
set lw-=set!

" Try to highlight all ly: procedures
syn match schemeFunc "ly:[^) ]\+"

LilyPond — Contributor’s Guide v2.19.46 (development-branch).