This PR adds “non-branching case statements”: For each inductive
constructor `T.con` this adds a function `T.con.with` that is similar
`T.casesOn`, but has only one arm (the one for `con`), and an additional
`t.toCtorIdx = 12` assumption.
For example:
```lean
inductive Vec (α : Type) : Nat → Type where
| nil : Vec α 0
| cons {n} : α → Vec α n → Vec α (n + 1)
/--
info: @[reducible] protected def Vec.cons.elim.{u} : {α : Type} →
{motive : (a : Nat) → Vec α a → Sort u} →
{a : Nat} →
(t : Vec α a) →
t.ctorIdx = 1 → ({n : Nat} → (a : α) → (a_1 : Vec α n) → motive (n + 1) (Vec.cons a a_1)) → motive a t
-/
#guard_msgs in
#print sig Vec.cons.elim
```
This is a building block for non-quadratic implementations of `BEq` and
`DecidableEq` etc.
Builds on top of #9951.
The compiled code for a these functions could presumably, without
branching on the inductive value, directly access the fields. Achieving
this optimization (and achieving it without a quadratic compilation
cost) is not in scope for this PR.
This PR adds a private `Lean.Name.getUtf8Byte'` to `Init.Meta` for a
future PR that optimizes `Lean.Name.escapePart`.
`Lean.Name.getUtf8Byte'` should be replaced with `String.getUtf8Byte`
once the string refactor is through.
This PR makes the generation of functional induction principles more
robust when the user `let`-binds a variable that is then `match`'ed on.
Fixes#10132.
this PR reorders the `DiscrTree.Key` constructors to match the order
given in the manually written `DiscrTree.Key.ctorIdx`. This allows us to
use the auto-generated one, and moreover lets this code benefit from
special compiler support for `.ctorIdx`, once that lands.
This PR generates `.ctorIdx` functions for all inductive types, not just
enumeration types. This can be a building block for other constructions
(`BEq`, `noConfusion`) that are size-efficient even for large
inductives.
It also renames it from `.toCtorIdx` to `.ctorIdx`, which is the more
idiomatic naming.
The old name exists as an alias, with a deprecation attribute to be
added after the next
stage0 update.
These functions can arguably compiled down to a rather efficient tag
lookup, rather than a `case` statement. This is future work (but
hopefully near future).
For a fair number of basic types the compiler is not able to compile a
function using `casesOn` until further definitions have been defined.
This therefore (ab)uses the `genInjectivity` flag and
`gen_injective_theorems%` command to also control the generation of this
construct.
For (slightly) more efficient kernel reduction one could use `.rec`
rather than `.casesOn`. I did not do that yet, also because it
complicates compilation.
This PR allows for more fine-grained control over what derived instances
have exposed definitions under the module system: handlers should not
expose their implementation unless either the deriving item or a
surrounding section is marked with `@[expose]`. Built-in handlers to be
updated after a stage 0 update.
This PR adds a stop position field to parser input contexts, allowing
the parser to be instructed to stop parsing prior to the end of a file.
This is step 1, prior to a stage0 update, to make run-time data
structures sufficiently compatible to avoid segfaults. After the update,
the actual code to stop parsing can be merged.
This PR enables core's `LakeMain` to be a `module` when core is built
without `USE_LAKE`.
This was a problem when porting Lake to the module system (#9749).
This PR changes Lake to not set `LEAN_GITHASH` when in core (i.e.
`bootstrap = true`). This avoids Lake rebuilding modules when the Lake
watchdog is on one build of Lean/Lake and the command line is on a
different one.
This PR cleans up `optParam`/`autoParam`/etc. annotations before
elaborating definition bodies, theorem bodies, `fun` bodies, and `let`
function bodies. Both `variable`s and binders in declaration headers are
supported.
There are no changes to `inductive`/`structure`/`axiom`/etc. processing,
just `def`/`theorem`/`example`/`instance`.
This PR removes the option `grind +ringNull`. It provided an alternative
proof term construction for the `grind ring` module, but it was less
effective than the default proof construction mode and had effectively
become dead code.
This PR also optimizes semiring normalization proof terms using the
infrastructure added in #9946.
**Remark:** After updating stage0, we can remove several background
theorems from the `Init/Grind` folder.
This PR addresses a missing check in the module system where private
names that remain in the public environment map for technical reasons
(e.g. inductive constructors generated by the kernel and relied on by
the code generator) accidentally were accessible in the public scope.
This PR restricts Lake's production of thin archives to only the Windows
core build (i.e., `bootstrap = true`). The unbundled `ar` usually used
for core builds on macOS does not support `--thin`, so we avoid using it
unless necessary.
