Add a (stack?/nix?/?) template for the simple/advanced project starting points

[silky]

I often want to start a new stacklock2nix project, but find myself copying-and-pasting from a previous example.

It would be convenient to use stack new and stack's templates ( https://github.com/commercialhaskell/stack-templates ) to get an starting point.

Trivia: It seems like stack-templates might not be accepting submissions though ( commercialhaskell/stack-templates#121 ) so not sure if this is a dead-end.

[silky]

Maybe a better alternative is a nix template that can be cloned via nix flakes?

[cdepillabout]

Yeah, that sounds like a good idea! I've thought of doing so, but haven't gotten around to it yet.

I don't personally use stack templates or Nix flake templates much myself, but I think other people definitely do. I imagine people in the Nix ecosystem will be more familiar with nix flake templates, but I don't have a strong opinion here.

I'm also not quite sure what goes in to creating or maintaining a Nix flake template, but if someone wanted to send a PR adding one (or at least explain in detail what I need to do to add one), I'd happily merge it.

A few things I've seen:

• There are a few Haskell flake templates available from the official flake templates repo: https://github.com/NixOS/templates. It probably wouldn't be crazy to add one for stacklock2nix (although maintaining it in a separate repo might be annoying).
• Here's an example Haskell Nix library that provides a flake template: https://haskell.flake.page/start and https://github.com/srid/haskell-flake. Something similar to the flake template provided here would probably be easy to add to the stacklock2nix repo.

[cdepillabout]

$ stack new
Usage: stack new PACKAGE_NAME [--bare] [TEMPLATE_NAME] [-p|--param KEY:VALUE] 
                 [DIR(S)] [--omit-packages] [--force] [--ignore-subdirs] 
                 [--setup-info-yaml URL] [--snapshot-location-base URL] [--help]
  Create a new project from a template. Run `stack templates' to see available
  templates. Will also initialise if there is no stack.yaml file. Note: you can
  also specify a local file or a remote URL as a template; or force an
  initialisation.

Available options:
  PACKAGE_NAME             A valid package name.
  --bare                   Do not create a subdirectory for the project
  TEMPLATE_NAME            Name of a template - can take the form
                           [[service:]username/]template with optional service
                           name (github, gitlab, or bitbucket) and username for
                           the service; or, a local filename such as foo.hsfiles
                           or ~/foo; or, a full URL such as
                           https://example.com/foo.hsfiles.
...

It looks like Stack templates can be on an arbitrary github repo, or just any URL. That might be pretty convenient for us as well.

Not sure whether more users would prefer a Nix Flake template, or a Stack template.

[silky]

yeah; i've definitely used the url-based stack templates before; but i think a nix template might make the most sense idiomatically here, because in theory one may not even have a system-installed stack ...

[silky]

there's also this - https://github.com/cookiecutter/cookiecutter - but i've never personally used it before.