This PR makes `IsPreorder`, `IsPartialOrder`, `IsLinearPreorder` and
`IsLinearOrder` extend `BEq` and `Ord` as appropriate, adds the
`LawfulOrderBEq` and `LawfulOrderOrd` typeclasses relating `BEq` and
`Ord` to `LE`, and adds many lemmas and instances.
Note: This PR contains a refactoring where `Init.Data.Ord` is moved to
`Init.Data.Ord.Basic`. If I added `Init.Data.Ord` simply importing all
submodules, git would not be able to determine that `Init.Data.Ord` was
renamed to `Init.Data.Ord.Basic`. This could lead to unnecessary merge
conflicts in the future. Hence, I chose the name `Init.Data.OrdRoot`
instead of `Init.Data.Ord` temporarily. After this PR, I will rename
this module back to `Init.Data.Ord` in a separate PR.
(This is a copy of #9430: I will not touch that PR because it currently
allows to debug a CI problem and pushing commits might break the
reproducibility.)
This PR adjusts the experimental module system to make `private` the
default visibility modifier in `module`s, introducing `public` as a new
modifier instead. `public section` can be used to revert the default for
an entire section, though this is more intended to ease gradual adoption
of the new semantics such as in `Init` (and soon `Std`) where they
should be replaced by a future decl-by-decl re-review of visibilities.
This PR moves `ReflBEq` to `Init.Core` and changes `LawfulBEq` to extend
`ReflBEq`.
**BREAKING CHANGES:**
- The `refl` field of `ReflBEq` has been renamed to `rfl` to match
`LawfulBEq`
- `LawfulBEq` extends `ReflBEq`, so in particular `LawfulBEq.rfl` is no
longer valid
This PR does some stage0 cleanup after #7100, and enables a warning when
the old `structure S extends P : Type` syntax is used. It also updates
the library to put resulting types in the new correct place (`structure
S : Type extends P`).
The `structure` elaborator also has some additional docstrings, and
`StructFieldKind.fromParent` is renamed to
`StructFieldKind.fromSubobject`.
Split from #4583
There are two open questions, opinions appreciated:
- Should this material be part of `Init` or `Std`?
- Should the typeclasses be in the `Std` namespace?
