Merge ShelleyLedgerEra and CardanoLedgerEra to a single type family LedgerEra

[newhoggy]

Changelog

- description: |
    Merge `ShelleyLedgerEra` and `CardanoLedgerEra` to a single type family `LedgerEra`
  type:
  # - feature        # introduces a new feature
  - breaking       # the API has changed in a breaking way
  # - compatible     # the API has changed but is non-breaking
  # - optimisation   # measurable performance improvements
  - improvement    # QoL changes e.g. refactoring
  # - bugfix         # fixes a defect
  # - test           # fixes/modifies tests
  # - maintenance    # not directly related to the code
  # - release        # related to a new release preparation
  # - documentation  # change in code docs, haddocks...

Context

We previously defined two separate type families ShelleyLedgerEra and CardanoLedgerEra but never use CardanoLedgerEra anywhere.

ShelleyLedgerEra is basically the same as CardanoLedgerEra except Byron is missing.

There is no reason to have two type families because CardanoLedgerEra works everywhere ShelleyLedgerEra currently does.

This PR merges the two type families into the one LedgerEra type family (which includes Byron) which shortens the commonly used name.

Doing this opens the possibility of unifying Byron with the other eras for the minimal set of operations we care to maintain for hard forking purposes.

How to trust this PR

Highlight important bits of the PR that will make the review faster. If there are commands the reviewer can run to observe the new behaviour, describe them.

Checklist

• Commit sequence broadly makes sense and commits have useful messages
• New tests are added if needed and existing tests are updated. See Running tests for more details
• Self-reviewed the diff

[newhoggy]

Delete this. Use LedgerEra instead.

[newhoggy]

Rename CardanoLedgerEra which is never used to LedgerEra which we use everywhere in place of ShelleyLedgerEra.

[carbolymer]

I think the change is pretty harmless, but can you check if anything breaks in cardano-cli?

[newhoggy]

Yep. Already checked.

[smelc]

LGTM 👍

[Jimbo4350]

This is not the direction we are taking cardano-api in. We do not care about all the eras, only mainnet and the upcoming era. The first step in this is to factor out the Byron era and only be concerned with shelley based eras. Consolidating the shelley based eras with cardano eras is moving in the wrong direction and prolongs this eventual separation.

[newhoggy]

It's worth noting that this PR doesn't commit us to a particular direction. On it's own it serves as a straightforward simplification. with the only impact on the rest of the code being a rename to a shorter one and removing a type we don't use anywhere.

replied

[Jimbo4350]

This is an unnecessary change. It is also incorrect because it implies the existence of types in Byron that do no exist. We will be able to simply things further after the Byron related code is isolated.

[newhoggy]

What type is Byron type is being implied that doesn't exist?

[Jimbo4350]

What type is Byron type is being implied that doesn't exist?

E.g

• https://github.com/input-output-hk/cardano-api/pull/361/files#diff-a2cdb35db95b47aeb4a7a8e6d2ec4eaaf18fcf82dfa5e920564dc3d37d731601R91
• https://github.com/input-output-hk/cardano-api/pull/361/files#diff-ca59c0fe9ce0404fb77f1d241d01e56c3e961d6e85d480596a8589bc5cb26517R69
• https://github.com/input-output-hk/cardano-api/pull/361/files#diff-cb9e0b224b5bf0f2ed6eae909fd1e36c82fdc4bfe5f45b5f78af1c0c66f4e5e8R103