The trace class Meta.synthInstance.answer isn't registered, so it can't
be used.
I set `inherited := true`, because I think it is a useful trace to have.
In particular it tells you when an instance has been found that has a
too large size. This is very useful information.
Summary:
- Take `synthPendingDepth` into account when caching TC results
- Add `maxSynthPendingDepth` option with default := 2.
- Add support for tracking `synthPending` failures when using
`set_option diagnostics true`
closes#2522closes#3313closes#3927
Identical to #4114 but with `maxSynthPendingDepth := 1`
closes#4114
cc @semorrison
We add a new configuration flag for `isDefEq`:
`Meta.Config.univApprox`.
When it is true, we approximate the solution for universe constraints
such as
- `u =?= max u ?v`, we use `?v := u`, and ignore the solution `?v := 0`.
- `max u v =?= max u ?w`, we use `?w := v`, and ignore the solution `?w
:= max u v`.
We only apply these approximations when there the contraints cannot be
postponed anymore. These approximations prevent error messages such as
```
error: stuck at solving universe constraint
max u ?u.3430 =?= u
```
This kind of error seems to appear in several Mathlib files.
We currently do not use these approximations while synthesizing type
class instances.
Remark: this commit removes the `jason1.lean` test. Motivation: It
breaks all the time due to changes we make, and it is not clear anymore
what it is testing.
---------
Co-authored-by: Joachim Breitner <mail@joachim-breitner.de>
This commit also removes parameter `simpleReduce` from discrimination
trees, and take WHNF configuration options.
Reason: it is more dynamic now. For example, the simplifier
will be able to use different configurations for discrimination tree insertion
and retrieval. We need this feature to address issues #2669 and #2281
This commit also removes the dead Meta.Config field `zetaNonDep`.
TODO: after we delete old code generator, we should replace
`@[alwaysInline, inline]` with `@[alwaysInline]`.
Remainder: we want the old code generator to ignore `@[alwaysInline]`
annotations, in particular, the new ones on `instance` commands that
are actually annotations for the instance methods.
