[petsc-dev] Style Guide: How to format single-line if/for/while-blocks?

[Karl Rupp]

Hi guys,

 >>>> Yes, though
>>>>
>>>> if (y < 12) {
>>>>    ierr = Something();CHKERRQ(ierr);
>>>> }
>>>>
>>>> takes three times as many lines. I don't care much either way, but it's
>>>> nice to not waste vertical space.
>>>
>>> I agree here.
>>
>> I've prefered the 1 liners as well.
>
> So, am I the only one that like the uniformity of the three-liner?

I think I'm currently on the best way towards a rabbit hole, with 
uncrustify lacking the full understanding of the code an thus bound to 
failure. Rather than tuning regular expressions and the like, I'll spend 
some time on investigate further what Clang can do for us.

First and foremost, it gives us access to the abstract syntax tree 
(AST), see e.g.
   http://clang.llvm.org/docs/IntroductionToTheClangAST.html
and already contains a formatter for Chromium-Style, Google-Style, 
LLVM-Style. The formatter for multiple Languages is currently less than 
2000 lines of code and eventually far more powerful than what we need.

Via the C-interface LibClang
  http://clang.llvm.org/doxygen/group__CINDEX.html
or LibTooling
  http://clang.llvm.org/docs/LibTooling.html
it's much more natural to generate *the* PETSc-representation of code 
irrespective of the input, and from the same AST generate e.g. the 
Knepley-representation of code. At the same time, Clang remains an 
optional dependency: One can work directly with the PETSc-representation 
without Clang installed.

Also, I found that they (Clang) are indeed aiming at a full code 
documentation generator:
   http://clang.llvm.org/OpenProjects.html
There is already a lot of parsing of Doxygen-style comments done in 
Clang and accessible via the AST, so it's mostly missing output 
generators only. It will take more time to reach maturity, though. It 
may, however, be just what it needs to replace sowing in terms of 
Fortran stubs generation and user manual generation.

Best regards,
Karli