This PR reviews the implicitness of arguments across List/Array/Vector,
generally trying to make arguments implicit where possible, although
sometimes correcting propositional arguments which were incorrectly
implicit to explicit.
This PR makes the signatures of `find` functions across
`List`/`Array`/`Vector` consistent. Verification lemmas will follow in
subsequent PRs.
We were previously quite inconsistent about the signature of
`indexOf`/`findIdx` functions across `List` and `Array`. Moreover, there
are still quite large gaps in the verification lemma coverage for these
even at the `List` level.
My intention is to make the signatures consistent by providing:
`findIdx` / `findIdx?` / `findFinIdx?` (these all take a predicate, and
return respectively a `Nat`, `Option Nat`, `Option (Fin l.length)`) and
similarly `idxOf` / `idxOf?` / `finIdxOf?` (which look for an element)
for each of List/Array/Vector. I've seen enough examples by now where
each variant is genuinely the most convenient at the call-site, so I'm
going to accept the cost of having many closely related functions.
*Hopefully* for the verification lemmas we can simp all of these into
"projections" of the `Option (Fin l.length)` versions, and then only
have to specify that.
However, I will not plan on immediately either filling in the missing
verification lemmas (or even deciding what the simp normal forms
relating these operations are), and just reach parity amongst
List/Array/Vector for what is already there.
`simp only` will not apply this simproc anymore. Users must now write
`simp only [reduceCtorEq]`. See RFC #5046 for motivation.
This PR also renames simproc to `reduceCtorEq`.
close#5046
@semorrison A few `simp only ...` tactics will probably break in
Mathlib. Fix: include `reduceCtorEq`.
