Stdlib: Argument parser for executables

[MuellerSeb]

Could this be a place to provide an argument parser in fortran?

Here are two implementations:

• https://github.com/haniibrahim/f90getopt
• https://github.com/cngilbreth/optionsf90

[milancurcic]

Yes, I think argument parsing is in scope. See also:

• https://github.com/szaghi/FLAP
• https://github.com/urbanjost/M_CLI2
• @everythingfunctional is working on one, I can't find the link now

[ivan-pi]

I've found the link for the one from @everythingfunctional:

• cmdff

There has also been a discussion of available modules for option parsing in https://github.com/fortran-lang/fpm/issues/135. Three more libraries I mentioned in that thread are:

• command_args from @arjenmarkus
• FTN_Getopt by Reinhold Bader
• libSUFR by @MarcvdSluys

I also believe that many of the libraries in the list of popular Fortran projects have their own argument parsers.

Given this much prior art, I think it is a good idea to draw up some kind of comparison table and identify what are the most commonly required features, and what kind of different programming approaches are used in practice.

[certik]

I think we all agree that stdlib should have command line parsing.

One way to get there is to first implement it as a separate library as an fpm package, and get projects use it, and then eventually include into stdlib as we get more real life usage, to ensure the API works.

[MuellerSeb]

AFAICT, https://github.com/urbanjost/M_CLI2 already provides a fpm package.

[urbanjost]

I did not quite get hooked into the process so I do not think that will be pulled in, but yes .. I made a branch that implemented all the command line parsing in the current FPM and all the functionality except the pull/curl request, and tdetermining the compilation order was primitive but I made that private so I could continue experimenting while the more critical TOML interface and gitlib/libcurl/system interfaces seemed to be racing along, and others seemed to be working on the CLI interface. Apparently I did not remove everything I thought I did. So the fpm CLI interface is gone from the M_CLI2 site but if anyone wants me to integrate that into a more recent fpm package let me know.