You can import tasks in remote files.

This is useful to depend on tasks specified in another package.

(package
  :name "atbuild"

  ;; import all the tasks in `atpkg/build.atpkg`.
  ;; These will be imported as `packagename.taskname`.
  ;; Since you cannot declare packages with periods manually, this 
  ;; cannot conflict with any current tasks
  :import-packages ["atpkg/build.atpkg"]

  ;; We can then depend on a target from the remote package in our current one

  :tasks {
    :mytask {
      :tool "atllbuild"
      :sources ["src/**.swift"]
      :name "mytask"
      :output-type "executable"
      :dependencies ["atpkg.atpkg"]
    }
  }
)

You can also reference remote tasks on the command line by providing their fully-qualified name:

$ atbuild atpkg.atpkg
$ atbuild mytask
$ atbuild atbuild.mytask #equivalent to previous line

Packages are imported in a flat topology; if a imports b and b imports c, use c.taskname to refer to the task, not b.c.taskname or a.b.c.taskname.

Implementation note

Remote packages may have paths specified in a key, like “source”. Quite possibly, these keys should be interpreted relative to the path the task was declared in, NOT the working directory.

To support this, Task has a property importedPath that tools may want to use.