* Add the `--preserveNull` flag and omit null fields by default on `dhall-to-yaml`
fixes#1354
* Restore the `--omitNull` flag and apply `--preserveNull` to `dhall-to-json`
* Adjust examples that return null fields
* Mention the default behaviour regarding nulls
* Null -> null
* Enable --pretty by default for dhall-to-json
* add Deprecation notice into dhall-to-json help
* update dhall-to-json output examples in src/Dhall/JSON.hs
* Fix `--version` flag handling for `dhall-json` package
Fixes https://github.com/dhall-lang/dhall-haskell/issues/1198
This changes version to be a separate constructor for options parsing,
in order to make invalid states unrepresentable and to fix issues like
the above one.
* Undo `allowImports` changed
This was a change I forgot to stash while working on the fix for the
`--version` flag
* Fix missing `Paths_dhall_json` in `dhall-json.cabal`
* Add `--file` option to `dhall-json` executables
Fixes https://github.com/dhall-lang/dhall-haskell/issues/1096
* s/JSON/expression/
... as caught by @sjakobi
Co-Authored-By: Simon Jakobi <simon.jakobi@gmail.com>
* s/expression/YAML expression/
... as caught by @sjakobi
Co-Authored-By: Simon Jakobi <simon.jakobi@gmail.com>
* Change the program descriptions for `{json,yaml}-to-dhall`
... as suggested by @sjakobi
Before, `dhall-to-json`/`dhall-to-yaml` would use approximate
representations for special `Double` values. Specifically, `NaN`
would encode as `null` and `±Infinity` would encode as the minimum
and maximum `Double` values.
After this change, YAML will now use `nan`/`inf`/`-inf` to encode
these values (since special `Double` values are natively supported
by YAML) and the JSON encoding will reject them by default. The
user can restore the old behavior for the JSON encoding by enabling
the `--approximate-special-doubles` flag.
... as proposed in https://github.com/dhall-lang/dhall-kubernetes/issues/46#issuecomment-468530601
`--omitEmpty` is the same as `--omitNull` except it also omits fields that
are empty records. To be precise, it omits fields whose transitive fields
are all `null` (and an empty record is a special case of a record whose
transitive fields are all `null` since it is vacuously true when there are
no fields).
This allows Dhall configurations that target YAML to avoid having to nest
sub-records inside of an `Optional` value. Omitting unnecessary `Optional`
layers reduces the number of default values that the configuration format
needs to thread around.
The motivation for this change is:
* To catch build failures in downstream packages whenever we make a breaking
change to the `dhall` API
* To reduce the amount of work I need in order to cut a release for all of
these packages
* To better share Nix/CI-related logic between the projects
Note that I have not yet migrated `dhall-nix` in. I'm waiting for
https://github.com/dhall-lang/dhall-nix/issues/17 to be fixed since
`dhall-nix` is incompatible with later versions of `megaparsec` due to
`hnix`.
