I noticed that a change to `Lean.PrettyPrinter.Delaborator.Builtins`
rebuilt more modules than I expected, so I moved a definition and
reduced some dependcies.
More reduction would be possible to move const-delaboration out of the
big `Lean.PrettyPrinter`, and import from `Lean.PrettyPrinter`
selectively.
Before, `pp.instantiateMVars` generally had no effect because most call
sites for the pretty printer instantiated metavariables first, but now
this functionality is entrusted upon the `pp.instantiateMVars` option.
This also has an effect in hovers, where metavariables can be unfolded
one assignment at a time. However, the goal state still sees all
metavariables instantiated due to the fact that the algorithm relies on
expression equality post-instantiation (see
`Lean.Widget.goalToInteractive`).
Closes#4406
* Setting `pp.mvars` to false causes metavariables to pretty print as
`?_`.
* Setting `pp.mvars.withType` to true causes metavariables to pretty
print with type ascriptions.
Motivation: when making tests, it is inconvenient using `#guard_msgs`
when there are metavariables, since the unique numbering is subject to
change.
This feature does not use `⋯` omissions since a metavariable is already
in a sense an omitted term. If repeated metavariables do not appear in
an expression, there is a chance that a term pretty printed with
`pp.mvars` set to false can still elaborate to the correct term, unlike
for other omissions.
(In the future we could consider an option that pretty prints uniquely
numbered metavariables as `?m✝`, `?m✝¹`, `?m✝²`, etc. to be able to tell
them apart, at least in the same pretty printed expression. It would
take care to make sure that these names are stable across different
hovers.)
Closes#3781
By having the `pp.proofs` feature use `⋯` when omitting proofs, when
users copy/paste terms from the InfoView the elaborator can give an
error message explaining why the term cannot be elaborated.
Also adds `pp.proofs.threshold` option to allow users to pretty print
shallow proof terms. By default, only atomic proof terms are pretty
printed.
This adjustment was suggested in PR #3201, which added `⋯` and the
related `pp.deepTerms` option.
To handle delaborating notations that are functions that can be applied
to arguments, extracts the core function application delaborator as a
separate function that accepts the number of arguments to process and a
delaborator to apply to the "head" of the expression.
Defines `withOverApp`, which has the same interface as the combinator of
the same name from std4, but it uses this core function application
delaborator.
Uses `withOverApp` to improve a number of application delaborators,
notably projections. This means Mathlib can stop using `pp_dot` for
structure fields that have function types.
Incidentally fixes `getParamKinds` to specialize default values to use
supplied arguments, which impacts how default arguments are delaborated.
---------
Co-authored-by: Sebastian Ullrich <sebasti@nullri.ch>
