[Proposal] Nix for a more sophisticated library system?

[KoviRobi]

Hi,

I'd like to propose Nix for a more sophisticated library system, there are a couple of benefits:

1. It's already written, and is very sophisticated.
2. It can also capture non-Bluespec dependencies, should some simulation need some other software
3. It has support for Linux and MacOS
4. It supports per-project packages
5. Bluespec is already packaged for it (and was perhaps one of the first package managers to have it packaged?)
6. It supports pre-compiled packages so that you can ship compiled libraries.

This is more to gauge interest/opinions, I can do the Nix bits. In the end I'd imagine it to look something like this:

1. You could install global packages, e.g. nix-env -i bsc-contrib
2. You can have per-project packages, with Nix these are described by a shell.nix file, e.g.

   # Imports default package set, optional argument,
   # can be overridden from the command line
   { nixpkgs ? import <nixpkgs> { }
   }:
   with nixpkgs; # Use the default package set namespace
   mkShell {
     buildInputs = # A list of the project dependencies
     [ bluespec # The already packaged bluespec compiler
       bsc-contrib # This repo
       # others...
       # Or to prevent it 'polluting' the lib/Libraries path, replace the above with
       (bluespec.withPackages [ bsc-contrib ])
     ];
   }

As an example, see https://gist.github.com/KoviRobi/1381abdfce8e87139e4d04cfef3d76be#file-example-bluespec-shell-nix-L16-L27 where the highlighted lines are an 'inline package'. Then we merge the libraries from the BlueSpec compiler and this repo with symlinkJoin. This is just a quick test, that I am using to play around with the connectal library.

There is one limitation of the BlueSpec compiler that I'm aware of, which is that it doesn't support either a nested namespace, or *.bo files pointing to their own dependencies, which means that essentially we have to have a flat path containing all the libraries a project uses (recursively), and this limits will lead to namespace clashes.

E.g. suppose a project has a file MagicNumbers.bsv (as an example), this means that no other dependency can have a MagicNumbers.bsv file.

This would need to be changed in the compiler.