[Feature Request] Usage of variables and functions in defining global variables

[FeryET]

Hi.

Right now if I want define a variable that can be declared easily via interpolation with other variables, I have to use 'executable line' format like this:

ABS_BASE_DIR := `echo "$(pwd)/some_dir"`

While IMO this could be way more readable and consistent:

ABS_BASE_DIR := '{{ justfile_directory() }}/some_dir'

We currently cannot interpolate global variables using other variables or pre-built functions in the recipe.

[casey]

Does this work? You can use the / operator like so:

foo := justfile_directory() / 'some_dir'

$ just --evaluate foo
foo := "/Users/bar/some_dir"

[FeryET]

Does this work? You can use the / operator like so:

foo := justfile_directory() / 'some_dir'

$ just --evaluate foo
foo := "/Users/bar/some_dir"

Yes, it works and it's awesome! Needs to be explicitly documented, tho.

Still in some cases variable interpolation is far easier to read and understand as it reminds people of go template engine or jinja. e.g.:

registry_url := 'example.registry.local'

image_name := 'python'

image_tag  := '3.8-slim'

full_image_id := '{{ registry_url }}/{{  image_name }}:{{  image_tag }}'

@build:
         docker build . -t {{ full_image_id }}

@push:
         docker push {{ full_image_id }}

[casey]

This is documented here. Interpolation is definitely wanted, see #11.