This PR enables transforming nondependent `let`s into `have`s in a
number of contexts: the bodies of nonrecursive definitions, equation
lemmas, smart unfolding definitions, and types of theorems. A motivation
for this change is that when zeta reduction is disabled, `simp` can only
effectively rewrite `have` expressions (e.g. `split` uses `simp` with
zeta reduction disabled), and so we cache the nondependence calculations
by transforming `let`s to `have`s. The transformation can be disabled
using `set_option cleanup.letToHave false`.
Uses `Meta.letToHave`, introduced in #8954.
Sets the default value to `pp.fieldNotation.generalized` to `true`.
Updates tests, and fixes some minor flaws in the implementation of the
generalized field notation pretty printer.
Now generalized field notation won't be used for any function that has a
`motive` argument. This is intended to prevent recursors from pretty
printing using it as (1) recursors are more like control flow structures
than actual functions and (2) generalized field notation tends to cause
elaboration problems for recursors.
Note: be sure functions that have an `@[app_unexpander]` use
`@[pp_nodot]` if applicable. For example, `List.toArray` needs
`@[pp_nodot]` to ensure the unexpander prints it using `#[...]`
notation.
closes#3022
With this commit, given the declaration
```
def foo : Nat → Nat
| 0 => 2
| n + 1 => foo n
```
when we unfold `foo (n+1)`, we now obtain `foo n` instead of `foo
(Nat.add n 0)`.
The approach using `matcherBelowDep : NameSet` was not correct because
we "reuse" matcher-declarations. For example, in the definition
```
def f : Nat → Bool
| 0 => true
| n + 1 => (match n with
| 0 => true
| _ + 1 => true) && f n
```
we have to `match`-expressions but they can be compiled the same
matcher `f.match_1`. Thus, the set `matcherBelowDep` would contain
`f.match_1` since the first occurence refined the `Nat.below` argument
at `mkBRecOn`. Thus, `addSmartUnfoldingDef` was incorrectly assuming the second
`match` was refined too.
We fixed this issue by simulating `mkBRecOn` behavior.
fixes#445
