This PR makes the docstrings in the `Char` namespace follow the
documentation conventions.
---------
Co-authored-by: Markus Himmel <markus@himmel-villmar.de>
This PR replaces `List.lt` with `List.Lex`, from Mathlib, and adds the
new `Bool` valued lexicographic comparatory function `List.lex`. This
subtly changes the definition of `<` on Lists in some situations.
`List.lt` was a weaker relation: in particular if `l₁ < l₂`, then
`a :: l₁ < b :: l₂` may hold according to `List.lt` even if `a` and `b`
are merely incomparable
(either neither `a < b` nor `b < a`), whereas according to `List.Lex`
this would require `a = b`.
When `<` is total, in the sense that `¬ · < ·` is antisymmetric, then
the two relations coincide.
Mathlib was already overriding the order instances for `List α`,
so this change should not be noticed by anyone already using Mathlib.
We simultaneously add the boolean valued `List.lex` function,
parameterised by a `BEq` typeclass
and an arbitrary `lt` function. This will support the flexibility
previously provided for `List.lt`,
via a `==` function which is weaker than strict equality.
I made a few choices so far that can probably be discussed:
- got rid of `modn` on `UInt`, nobody seems to use it apart from the
definition of `shift` which can use normal `mod`
- removed the previous defeq optimized definition of `USize.size` in
favor for a normal one. The motivation was to allow `OfNat` to work
which doesn't seem to be necessary anymore afaict.
- Minimized uses of `.val`, should we maybe mark it deprecated?
- Mostly got rid of `.val` in basically all theorems as the proper next
level of API would now be `.toBitVec`. We could probably re-prove them
but it would be more annoying given the change of definition.
- Did not yet redefine `log2` in terms of `BitVec` as this would require
a `log2` in `BitVec` as well, do we want this?
- I added a couple of theorems around the relation of `<` on `UInt` and
`Nat`. These were previously not needed because defeq was used all over
the place to save us. I did not yet generalize these to all types as I
wasn't sure if they are the appropriate lemma that we want to have.
This PR roughly halves the time needed to load the .ilean files by
optimizing the JSON parser and the conversion from JSON to Lean data
structures.
The code is optimized roughly as follows:
- String operations are inlined more aggressively
- Parsers are changed to use new `String.Iterator` functions `curr'` and
`next'` that receive a proof and hence do not need to perform an
additional check
- The `RefIdent` of .ilean files now uses a `String` instead of a `Name`
to avoid the expensive parse step from `String` to `Name` (despite the
fact that we only very rarely actually need a `Name` in downstream code)
- Instead of `List`s and `Subarray`s, the JSON to Lean conversion now
directly passes around arrays and array indices to avoid redundant
boxing
- Parsec's `peek?` sometimes generates redundant `Option` wrappers
because the generation of basic blocks interferes with the ctor-match
optimization, so it is changed to use an `isEof` check where possible
- Early returns and inline-do-blocks cause the code generator to
generate new functions, which then interfere with optimizations, so they
are now avoided
- Mutual defs are used instead of unspecialized passing of higher-order
functions to generate faster code
- The object parser is made tail-recursive
This PR also fixes a stack overflow in `Lean.Json.compress` that would
occur with long lists and adds a benchmark for the .ilean roundtrip
(compressed pretty-printing -> parsing).
This PR refactors the 'ext' attribute and implements the following
features:
- The 'local' and 'scoped' attribute kinds are now usable.
- The attribute realizes the `ext`/`ext_iff` lemmas when they do not
already exist, rather than always generating them. This is useful in
conjunction with `@[local ext]`.
- Adding `@[ext]` to a user ext lemma now realizes an `ext_iff` lemma as
well; formerly this was only for structures. The name of the generated
`ext_iff` theorem for a user `ext` theorem named `A.B.myext` is
`A.B.myext_iff`. If this process leads to an error, the user can write
`@[ext (iff := false)]` to disable this feature.
Breaking changes:
- Now the "x" and "y" term arguments to the realized `ext` and `ext_iff`
lemmas are implicit.
- Now the realized `ext` and `ext_iff` lemmas are protected.
Bootstrapping notes:
- There are a few `ext_iff` lemmas to address after the next stage0
update.
Closes https://github.com/leanprover/lean4/issues/3643
Suggested by Floris [on
Zulip](https://leanprover.zulipchat.com/#narrow/stream/113488-general/topic/.22Missing.20Tactics.22.20list/near/446267660).
It seems:
* there was no actual need for the UInt32 valued version
* downstream we were getting duplicative lemmas about both
* so lets reduce the API surface area!
If anyone would prefer the remaining function is still called
`Char.utf8Size` I will happily change it. (`size` is hopefully still
unambiguous, and it's helpful to rename here so we can give a
deprecation warning that explains the type signature change.)
---------
Co-authored-by: Mac Malone <tydeu@hatpress.net>
for SSFT24 summer school: https://github.com/david-christiansen/ssft24
---------
Co-authored-by: Kim Morrison <kim@tqft.net>
Co-authored-by: Kim Morrison <scott.morrison@gmail.com>
Co-authored-by: David Thrane Christiansen <david@davidchristiansen.dk>
