This PR adds `BEq` instance for `DHashMap`/`HashMap`/`HashSet` and their
extensional variants and proves lemmas relating it to the equivalence of
hashmaps/equality of extensional variants.
This PR reviews the docstrings for `Std.Do` that will appear in the Lean
reference manual and adds those that were missing.
---------
Co-authored-by: Sebastian Graf <sgraf1337@gmail.com>
This PR introduces a new fixpoint combinator,
`WellFounded.extrinsicFix`. A termination proof, if provided at all, can
be given extrinsically, i.e., looking at the term from the outside, and
is only required if one intends to formally verify the behavior of the
fixpoint. The new combinator is then applied to the iterator API.
Consumers such as `toList` or `ForIn` no longer require a proof that the
underlying iterator is finite. If one wants to ensure the termination of
them intrinsically, there are strictly terminating variants available
as, for example, `it.ensureTermination.toList` instead of `it.toList`.
Hi, these are just some spelling corrections.
There is one I wasn't completely sure about in
src/Init/Data/List/Lemmas.lean:
> See also
> ...
> Also
> \* \`Init.Data.List.Monadic\` for **addiation** _(additional?)_ lemmas
about \`List.mapM\` and \`List.forM\`
This PR adds a difference operation on
`ExtDTreeMap`/`ExtTreeMap`/`TreeSet` and proves several lemmas about it.
Stacked on top of #11407
---------
Co-authored-by: Markus Himmel <markus@himmel-villmar.de>
This PR adds support for the difference operation for
`ExtDHashMap`/`ExtHashMap`/`ExtHashSet` and proves several lemmas about
it.
---------
Co-authored-by: Markus Himmel <markus@himmel-villmar.de>
This PR adds lemmas stating that if a get operation returns a value,
then the queried key must be contained in the collection. These lemmas
are added for HashMap and TreeMap-based collections, with a similar
lemma also added for `Init.getElem`.
This PR moves the `Inhabited` instances in constant `DTreeMap` (and
related) queries, such as `Const.get!`, where the `Inhabited` instance
can be provided before proving a key.
This PR fixes various typos across the codebase in documentation and
comments.
- `infered` → `inferred` (ParserCompiler.lean)
- `declartation` → `declaration` (Cleanup.lean)
- `certian` → `certain` (CasesInfo.lean)
- `wil` → `will` (Cache.lean)
- `the the` → `the` (multiple files - PrefixTree.lean, Sum/Basic.lean,
List/Nat/Perm.lean, Time.lean, Bounded.lean, Lake files)
- `to to` → `to` (MutualInductive.lean, simp_bubblesort_256.lean)
- Grammar improvements in Bounded.lean and Time.lean
All changes are to comments and documentation only - no functional
changes.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude <noreply@anthropic.com>
This PR adds the difference operation on `DTreeMap`/`TreeMap`/`TreeSet`
and proves several lemmas about it.
---------
Co-authored-by: Markus Himmel <markus@himmel-villmar.de>
This PR lets recursive functions defined by well-founded recursion use a
different `fix` function when the termination measure is of type `Nat`.
This fix-point operator use structural recursion on “fuel”, initialized
by the given measure, and is thus reasonable to reduce, e.g. in `by
decide` proofs.
Extra provisions are in place that the fixpoint operator only starts
reducing when the fuel is fully known, to prevent “accidential” defeqs
when the remaining fuel for the recursive calls match the initial fuel
for that recursive argument.
To opt-out, the idiom `termination_by (n,0)` can be used.
We still use `@[irreducible]` as the default for such recursive
definitions, to avoid unexpected `defeq` lemmas. Making these functions
`@[semireducible]` by default showed performance regressions in lean.
When the measure is of type `Nat`, the system will accept an explicit
`@[semireducible]` without the usual warning.
Fixes#5234. Fixes: #11181.
This PR adds support for difference operation for
`DHashMap`/`HashMap`/`HashSet` and proves several lemmas about it.
---------
Co-authored-by: Markus Himmel <markus@himmel-villmar.de>
This PR adds `ofArray` to `DHashMap`/`HashMap`/`HashSet` and proves a
simp lemma allowing to rewrite `ofArray` to `ofList`.
---------
Co-authored-by: Markus Himmel <markus@himmel-villmar.de>
This PR changes the interface of the `ForIn`, `ForIn'`, and `ForM`
typeclasses to not take a `Monad m` parameter. This is a breaking change
for most downstream `instance`s, which will will now need to assume
`[Monad m]`.
The rationale is that if the provider of an instance requires `m` to be
a Monad, they should assume this up front. This makes it possible for
the instanve to assume `LawfulMonad m` or some other stronger
requirement, and also to provided a concrete instance for a particular
`m` without assuming a non-canonical `Monad` structure on it.
Zulip: [#lean4 > Monad assumptions in fields of other typeclasses @
💬](https://leanprover.zulipchat.com/#narrow/channel/270676-lean4/topic/Monad.20assumptions.20in.20fields.20of.20other.20typeclasses/near/537102158)
This PR renames `String.ValidPos` to `String.Pos`, `String.endValidPos`
to `String.endPos` and `String.startValidPos` to `String.startPos`.
Accordingly, the deprecations of `String.Pos` to `String.Pos.Raw` and
`String.endPos` to `String.rawEndPos` are removed early, after an
abbreviated deprecation cycle of two releases.
This PR significantly changes the signature of the `ToIterator` type
class. The obtained iterators' state is no longer dependently typed and
is an `outParam` instead of being bundled inside the class. Among other
benefits, `simp` can now rewrite inside of `Slice.toList` and
`Slice.toArray`. The downside is that we lose flexibility. For example,
the former combinator-based implementation of `Subarray`'s iterators is
no longer feasible because the states are dependently typed. Therefore,
this PR provides a hand-written iterator for `Subarray`, which does not
require a dependently typed state and is faster than the previous one.
Converting a family of dependently typed iterators into a simply typed
one using a `Sigma`-state iterator generates forbiddingly bad code, so
that we do provide such a combinator. This PR adds a benchmark for this
problem.
This PR renames congruence lemmas for union on
`DHashMap`/`HashMap`/`HashSet`/`DTreeMap`/`TreeMap`/`TreeSet` to fit the
convention of being in the `Equiv` namespace.
This PR renames `String.replaceStartEnd` to `String.slice`,
`String.replaceStart` to `String.sliceFrom`, and `String.replaceEnd` to
`String.sliceTo`, and similar for the corresponding functions on
`String.Slice`.
This PR adds several lemmas that relate
`getMin`/`getMin?`/`getMin!`/`getMinD` and insertion to the empty
(D)TreeMap/TreeSet and their extensional variants.
---------
Co-authored-by: Markus Himmel <markus@himmel-villmar.de>
This PR provides intersection operation for
`ExtDHashMap`/`ExtHashMap`/`ExtHashSet` and proves several lemmas about
it.
---------
Co-authored-by: Markus Himmel <markus@himmel-villmar.de>
This PR provides intersection on `DTreeMap`/`TreeMap`/`TreeSet`and
provides several lemmas about it.
---------
Co-authored-by: Markus Himmel <markus@himmel-villmar.de>
This PR redefines `String.take` and variants to operate on
`String.Slice`. While previously functions returning a substring of the
input sometimes returned `String` and sometimes returned
`Substring.Raw`, they now uniformly return `String.Slice`.
This is a BREAKING change, because many functions now have a different
return type. So for example, if `s` is a string and `f` is a function
accepting a string, `f (s.drop 1)` will no longer compile because
`s.drop 1` is a `String.Slice`. To fix this, insert a call to `copy` to
restore the old behavior: `f (s.drop 1).copy`.
Of course, in many cases, there will be more efficient options. For
example, don't write `f <| s.drop 1 |>.copy |>.dropEnd 1 |>.copy`, write
`f <| s.drop 1 |>.dropEnd 1 |>.copy` instead. Also, instead of `(s.drop
1).copy = "Hello"`, write `s.drop 1 == "Hello".toSlice` instead.
This PR adds intersection operation on `DHashMap`/`HashMap`/`HashSet`
and provides several lemmas about its behaviour.
---------
Co-authored-by: Markus Himmel <markus@himmel-villmar.de>
This PR removes duplicated instance parameters in the standard library
and flips lemmas of the form `toList_eq_toListIter` into a form that is
suitable for `simp`.
This PR provides a polymorphic `ForIn` instance for slices and an MPL
`spec` lemma for the iteration over slices using `for ... in`. It also
provides a version specialized to `Subarray`.
This ensures that no `grind` annotated theorem, simply by being
instantiated, causes a chain of >20 further instantiations, with a small
list of documented exceptions.
This PR introduces slices of lists that are available via slice notation
(e.g., `xs[1...5]`).
* Moved the `take` combinator and the `List` iterator producer to
`Init`.
* Introduced a `toTake` combinator: `it.toTake` behaves like `it`, but
it has the same type as `it.take n`. There is a constant cost per
iteration compared to `it` itself.
* Introduced `List` slices. Their iterators are defined as
`suffixList.iter.take n` for upper-bounded slices and
`suffixList.iter.toTake` for unbounded ones.
Performance characteristics of using the slice `list[a...b]`:
* when creating it: `O(a)`
* every iterator step: `O(1)`
* `toList`: `O(b - a + 1)` (given that a <= b)
Because the slice only stores a suffix of `xs` internally, two slices
can be equal even though the underlying lists differ in an irrelevant
prefix. Because the `stop` field is allowed to be beyond the list's
upper bound, the slices `[1][0...1]` and `[1][0...2]` are not equal,
even though they effectively cover the same range of the same list.
Improving this would require us to call `List.length` when building the
slice, which would iterate through the whole list.
This PR replaces `Iter(M).size` with the `Iter(M).count`. While the
former used a special `IteratorSize` type class, the latter relies on
`IteratorLoop`. The `IteratorSize` class is deprecated. The PR also
renames lemmas about ranges be replacing `_Rcc` with `_rcc`, `_Rco` with
`_roo` (and so on) in names, in order to be more consistent with the
naming convention.
This PR adds iterators and slices for `DTreeMap`/`TreeMap`/`TreeSet`
based on zippers and provides basic lemmas about them.
---------
Co-authored-by: Markus Himmel <markus@himmel-villmar.de>
This PR removes all uses of `String.Iterator` from core, preferring
`String.ValidPos` instead.
In an upcoming PR, `String.Iterator` will be renamed to
`String.Legacy.Iterator`.
This PR adds union operations on DTreeMap/TreeMap/TreeSet and their raw
variants and provides lemmas about union operations.
---------
Co-authored-by: Paul Reichert <6992158+datokrat@users.noreply.github.com>
This PR renames theorems that use `sorted` in their name to instead use
`pairwise`.
Closes#10742.
---------
Co-authored-by: Markus Himmel <markus@lean-fro.org>
This PR splits some low-hanging fruit out of `Init.Data.String.Basic`:
basic material about `String.Pos.Raw`, `String.Substrig`, and
`String.Iterator`.
More splitting required and the remaining material is quite unorganized,
but it's a start.
