`--file` option for `dhall-to-yaml`

[alexhumphreys]

I see there's a --file option for the dhall executable, as mentioned here #1004

Would it be possible to add this to dhall-to-yaml? I find it easier to keep my import paths in order when I don't have to worry about what my current directory is when playing with STDIN.

[f-f]

It could also be a good idea to just bundle dhall-to-json and dhall-to-yaml into the dhall executable itself, as we already did for dhall-to-text in #1087 (AFAIK it wouldn't change much the dependency footprint, most of the dependencies are already overlapping)

[Gabriella439]

@f-f: There should be a separate issue to discuss that, but the main issue we're running into is that the dhall package is actually doing two separate things:

• Providing a native Haskell binding
• Providing the dhall executable

If we could split out the native Haskell binding into a smaller separate package (i.e. dhall-core or dhall-api) and leave the dhall package for the executable (and re-exporting the Haskell API for backwards compatibility) then I'd have fewer reservations about adding extra dependencies to the dhall package. The reason why is that I'd like people using dhall as a native Haskell binding to have a smaller dependency footprint.

For example, if they were separate packages then somebody using the executable-free package to configure their Haskell program wouldn't need to depend on repline, aeson, aeson-pretty, Diff, dotgen, cborg-json, or ansi-terminal. Similarly, we could freely add dependencies like yaml to the executable package guilt-free.

@alexhumphreys: Yeah, I can add a --file option to the various executables built by the dhall-json package.

[f-f]

@Gabriel439 agreed! Opened #1102 to discuss this

[Gabriella439]

Fix is up here: #1107

[alexhumphreys]

Sweet, thank you!