Closes#3146
Reduction doesn't trigger correctly on the bodies of `let`-expressions
in `StructInst`, leading some meta-variables to linger in the terms of
some fields. Because of this, default fields may try multiple times (and
fail) to be generated, leading to an unexpected error.
The solution implemented here is to modify the values of the introduced
variables in the local context so as to reduce them correctly.
The `liftCommandElabM : CommandElabM α -> CoreM α` function now carries
over macro scopes, the name generator, info trees, and messages.
Adds a flag `throwOnError`, which is true by default. When it is true,
then if the messages contain an error message, it is converted into an
exception. In this case, the infotrees and messages are not carried
over; the motivation is that `throwOnError` is likely used for synthetic
syntax, and so the info and messages on errors will just be noise.
Cleanup of #5650
* default `Modifiers.stx` to missing
* rename and clarify `addDeclarationRangesFromSyntax` as the main
convenience function for user metaprograms
Example new output:
```text
failed to compile 'partial' definition 'checkMyList', could not prove that the type
ListNode → Bool × ListNode
is nonempty.
This process uses multiple strategies:
- It looks for a parameter that matches the return type.
- It tries synthesizing 'Inhabited' and 'Nonempty' instances for the return type.
- It tries unfolding the return type.
If the return type is defined using the 'structure' or 'inductive' command, you can try
adding a 'deriving Nonempty' clause to it.
```
The inhabitation prover now also unfolds definitions when trying to
prove inhabitation. For example,
```lean
def T (α : Type) := α × α
partial def f (n : Nat) : T Nat := f n
```
Motivated [by
Zulip](https://leanprover.zulipchat.com/#narrow/channel/113489-new-members/topic/Why.20return.20type.20of.20partial.20function.20MUST.20.60inhabited.60.3F/near/477905312)
Refactors `inductive` elaborator to keep track of universe level
parameters created during elaboration of `variable`s and binders. This
fixes an issue in Mathlib where its `Type*` elaborator can result in
unexpected universe levels.
For example, in
```lean4
variable {F : Type*}
inductive I1 (A B : Type*) (x : F) : Type
```
before this change the signature would be
```
I1.{u_1, u_2} {F : Type u_1} (A : Type u_1) (B : Type u_2) (x : F) : Type
```
but now it is
```
I1.{u_1, u_2, u_3} {F : Type u_1} (A : Type u_2) (B : Type u_3) (x : F) : Type
```
Fixes this for the `axiom` elaborator too.
Adds more accurate universe level validation for mutual inductives.
Breaking change: removes `Lean.Elab.Command.expandDeclId`. Use
`Lean.Elab.Term.expandDeclId` from within `runCommandElabM`.
Breaking changes:
To build Lean from source on Windows, it is now necessary to install the
[Windows
SDK](https://developer.microsoft.com/en-us/windows/downloads/windows-sdk/).
The build instructions have been updated to reflect this. Note that the
Windows SDK is **not** needed to compile Lean programs using a Lean
toolchain obtained using `elan`. The Windows SDK is only needed to build
Lean itself from source.
Furthermore, we are dropping support for Windows versions older than
Windows 10 1903 (released in May 2019).
No Windows version that is still supported by Microsoft as part of
mainstream support is affected by this.
The following Windows versions are still supported by Microsoft as part
of commercial extended support but are no longer supported by Lean:
- Windows 10 Enterprise LTSC 2015
- Windows 10 Enterprise LTSC 2016
- Windows 10 Enterprise LTSC 2019
- Windows Server 2019
It's difficult to distinguish theorems from regular definitions in the
completion menu, which is annoying when using completion for searching
one or the other. This PR makes theorem completions use the "Eureka!"
icon ()
to distinguish them more clearly from other completions.
NB: We are very limited in terms of which icons we can pick here since
[the completion kinds provided by LSP / VS
Code](https://code.visualstudio.com/docs/editor/intellisense#_types-of-completions)
are optimized for object-oriented programming languages, but I think
this choice strikes a nice balance between being easy to identify,
having some visual connection to theorem proving and not being used a
lot in other languages and thus not clashing with pre-existing
associations.
Between #3106 and this, it was possible that reparsing the file up to
the current position was stuck waiting in the threadpool queue,
displaying a yellow bar and not displaying any info on the unchanged
prefix.
`instantiate_mvars` is now implemented in C/C++, and makes many calls to
`has_fvar`, `has_mvar`. The new C/C++ implementations are inlined and
avoid unnecessary RC inc/decs.
Previously `RecursorVal.getInduct` would return the prefix of the
recursor’s name, which is unlikely the right value for the “derived”
recursors in nested recursion. The code using `RecursorVal.getInduct`
seems to expect the name of the inductive type of major argument here.
If we return that name, this fixes#5661.
This bug becomes more visible now that we have structural mutual
recursion.
Also, to avoid confusion, renames the function to ``getMajorInduct`.
This PR simplifies the signature of `Array.mapIdx`, to take a function
`f : Nat \to \a \to \b` rather than a function `f : Fin as.size \to \a
\to \b`.
Lean doesn't actually use the extra generality anywhere (so in fact this
change *simplifies* all the call sites of `Array.mapIdx`, since we no
longer need to throw away the proof).
This change would make the function signature equivalent to
`List.mapIdx`, hence making it easier to write verification lemmas.
We keep the original behaviour as `Array.mapFinIdx`.
This replaces `export Lean (Name NameMap)` and `export System
(SearchPath FilePath)` with the relevant `open` commands. This fixes
docgen output so that it can refer to, for example, `Lean.Name` instead
of `Lake.Name`.
The reason for these `export`s was convenience: by doing `open Lake` you
could get these aliases for free. However, aliases affect pretty
printing, and the Lake aliases took precedence. We don't want to disable
pretty printing re-exported names because this can be a valid pattern
(names could incrementally get re-exported from namespace to parent
namespace).
In the future we might implement a feature to be able to `scoped open`
some names.
Breaking change: Lakefiles that refer to `FilePath` may need to change
this to `System.FilePath` or otherwise add `open System (FilePath)`.
Closes#2524
This PR resolves the following issues related to goal state display:
1. In a new line after a `case` tactic with a completed proof, the state
of the proof in the `case` would be displayed, not the proof state after
the `case`
1. In the range of `next =>` / `case' ... =>`, the state of the proof in
the corresponding case would not be displayed, whereas this is true for
`case`
1. In the `suffices ... by` tactic, the tactic state of the `by` block
was not displayed after the `by` and before the first tactic
The incorrect goal state after `case` was caused by `evalCase` adding a
`TacticInfo` with the full block proof state for the full range of the
`case` block that the goal state selection has no means of
distinguishing from the `TacticInfo` with the same range that contains
the state after the whole `case` block. Narrowing the range of this
`TacticInfo` to `case ... =>` fixed this issue.
The lack of a case proof state on `next =>` was caused by the `case`
syntax that `next` expands to receiving noncanonical synthetic
`SourceInfo`, which is usually ignored by the language server. Adding a
token antiquotation for `next` fixed this issue.
The lack of a case proof state on `case' ... =>` was caused by
`evalCase'` not adding a `TacticInfo` with the full block state to the
range of `case' ... =>`. Adding this `TacticInfo` fixed this issue.
The tactic state of the block not being displayed after the `by` was
caused by the macro expansion of `suffices` to `have` not transferring
the trailing whitespace of the `by`. Ensuring that this trailing
whitespace information is transferred fixed this issue.
Fixes#2881.
Should ensure we visit at most as many expr nodes as in the final expr
instead of many possibly overlapping mvar assignments. This is likely
the only way we can ensure acceptable performance in all cases.
---------
Co-authored-by: Kim Morrison <kim@tqft.net>
this option was added in fb97275dcb to
prepare for #4595, due to boostrapping issues, but #4595 has not landed
yet. This is be very confusing when people discover this option and try
to use it (as I did).
So let's clearly mark this as not yet implemented on `master`, and add
the
docstring only with #4595.
