Uniform formatting of CP2K source code is enabled by a prettify script that is an almost complete auto-formatter for Fortran 90 source code. As a rule of thumb, developers should not worry about the format of their code and just let prettify do its magic by running
make -j pretty.
The following formatting conventions are automatically enforced by the
make -j pretty command:
USEstatements, removal of unused list entries.
(/or with an assignment operator
=>. If none of the above is present, a default hanging indent of 3 characters is applied.
You can optionally integrate prettify into your editor. First install prettify with the
setup.py script in
./setup.py install --user
Then configure your editor such that it calls
fprettify --no-normalize-use --no-report-errors
for reformatting. For Vim, this is done by adding the following line to your vimrc:
autocmd Filetype fortran setlocal formatprg=fprettify\ --no-normalize-use\ --no-report-errors
Reformat selected lines with
gq and the whole file with
gggqG. Note that editor integration only supports whitespace formatting (so you should still run
make pretty before a commit).
The following formatting decisions are still manual and are never changed by prettify:
IFstatements that are aligned with each other.
There may be cases where manual alignment is preferred over the automatic formatting conventions. The following options for manual formatting are provided:
A few examples to illustrate how to deal with cases where auto-formatting produces unsatisfying results:
! No: long_result_var_name = long_function_name(arg_1, arg_2, & arg_3, arg_4, arg_5)+ & foo ! Yes: long_result_var_name = & long_function_name( & arg_1, arg_2, & arg_3, arg_4, arg_5)+ & foo
! No: bessj0 = (r1+y*(r2+y*(r3+y*(r4+y* & (r5+y*r6)))))/(s1+y*(s2+y*(s3+y* & (s4+y*(s5+y*s6))))) ! Yes: bessj0 = (r1+y*(r2+y*(r3+y*(r4+y*(r5+y*r6)))))/ & (s1+y*(s2+y*(s3+y*(s4+y*(s5+y*s6)))))
! No: foo = bar+foobar(x1, y1, z1)* & foobar(x2, y2, z2)* & foobar(x3, y3, z3) ! Yes: foo = bar+(foobar(x1, y1, z1)* & foobar(x2, y2, z2)* & foobar(x3, y3, z3))
! Auto-formatting: align_me = [-1, 10, 0, & 0, 1000, 0, & 0, -1, 1] ! Manual alignment (!& disables whitespace formatting): align_me = [-1, 10, 0, & !& 0, 1000, 0, & !& 0, -1, 1] !& ! Alternatively: !&< align_me = [-1, 10, 0, & 0, 1000, 0, & 0, -1, 1] !&>