This PR improves the error messages produced by invalid projections and
field notation. It also adds a hint to the "function expected" error
message noting the argument to which the term is being applied, which
can be helpful for debugging spurious "function expected" messages
actually caused by syntax errors.
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Co-authored-by: Joachim Breitner <mail@joachim-breitner.de>
This PR adjusts the way the pretty printer unresolves names. It used to
make use of all `export`s when pretty printing, but now it only uses
`export`s that put names into parent namespaces (heuristic: these are
"API exports" that are intended by the library author), rather than
"horizontal exports" that put the names into an unrelated namespace,
which the dot notation feature in #6189 now incentivizes.
Closes the already closed#2524
This PR changes how generalized field notation ("dot notation") resolves
the function. The new resolution rule is that if `x : S`, then `x.f`
resolves the name `S.f` relative to the root namespace (hence it now
affected by `export` and `open`). Breaking change: aliases now resolve
differently. Before, if `x : S`, and if `S.f` is an alias for `S'.f`,
then `x.f` would use `S'.f` and look for an argument of type `S'`. Now,
it looks for an argument of type `S`, which is more generally useful
behavior. Code making use of the old behavior should consider defining
`S` or `S'` in terms of the other, since dot notation can unfold
definitions during resolution.
This also fixes a bug in explicit-mode generalized field notation
(`@x.f`) where `x` could be passed as the wrong argument. This was not a
bug for explicit-mode structure projections.
Closes#3031. Addresses the `Function` namespace issue in #1629.
