Syntax Highlighting
Decently syntax highlighted Fortran code on the internet is hard to come by. None of the major sites where people are likely to visit to learn about Fortran have it:
- The Google Groups hosting of comp.lang.fortran (I don't really expect much from this one since it's just Usenet.)
- Stack Overflow (we should expect better from them, since they have had syntax highlighting for many other languages for years.) It looks like they are using Google's code-prettify (which seems to have a pull request ready to provide syntax highlighting for Fortran, so perhaps there is hope?)
- Intel Fortran compiler documentation [example] (people pay good money for this compiler, and so should ask for better documentation).
- GFortran documentation (their entire Fortran website looks like it is from the late 1990s, and could certainly use an overhaul).
Luckily GitHub has syntax highlighting for Fortran, as well as the Fortran Wiki.
Personally, I hate looking at non-syntax highlighted code. It's not aesthetically pleasing and I find it hard to read. On this blog, I'm using a Fortran plugin for SyntaxHighlighter Evolved, which I downloaded somewhere at some point and have modified to account for various newer Fortran language features. It's not perfect, but it looks pretty good.
Consider this example from the gfortran website:
Now that looks just awful, and not just because they are using ancient syntax such as (/, /), and .eq.. Whereas the following syntax-highlighted one looks great:
program test_all
implicit none
logical :: l
l = all([.true., .true., .true.])
write(*,*) l
call section()
contains
subroutine section()
integer,dimension(2,3) :: a, b
a = 1
b = 1
b(2,2) = 2
write(*,*) all(a == b, 1)
write(*,*) all(a == b, 2)
end subroutine section
end program test_all
FORD-produced documentation has nice syntax highlighting for Fortran code provided by Pygments (which is written in Python). An example can be found here. Rouge is another code highlighter (written in Ruby) that supports Fortran and can output as HTML. Both Pygments and Rouge are open source and released under permissive licenses.