This was somewhat weirdly done, with a boolean 'imported' set on the
formers; but an explicit new warning for values. I don't see the point
of distinguishing them so I just merged them all into a single
warning.
I have however preserved the 'UnusedType' and 'UnusedConstructor'
warnings since they were ALSO used for unused private constructors or
types.
I initially removed the 'UnkownTypeConstructor' since it wasn't used anywhere and was in fact dead-code. On second thoughts however, it is nicer to provide a slightly better error message when a constructor is missing as well as some valid suggestion. Prior to that commit, we would simply return a 'UnknownVariable' and the hint might suggest lowercase identifiers; which is wrong.
- Add support to the formatter for these doc comments
- Add a new field to `Arg` `doc: Option<String>`
- Don't attach docs immediately after typechecking a module
- instead we should do it on demand in docs, build, and lsp
- the check command doesn't need to have any docs attached
- doing it more lazily defers the computation until later making
typechecking feedback a bit faster
- Add support for function arg and validator param docs in
`attach_module_docs` methods
- Update some snapshots
- Add put_doc to Arg
closes#685
This improves error messages for `a |> b(x)`.
We need to do a special check when looping over the args
and unifying. This information is within a function that does not belong
to pipe typer so I used a closure to forward along a way to add
metadata to the error when the first argument in the loop has a
unification error. Simply adding the metadata at the pipe typer
level is not good enough because then we may annotate regular
unification errors from the args.
When rendering missing or redundant patterns, linked-list would
wrongly suggest the last nil constructor as a pattern on non-empty
list.
For example, before this commit, the exhaustivness checker would yield:
```
[(_, True), []]
```
as a suggestion, for being the result of being a list pattern with a
single argument being `(_, True) :: Nil`. Blindly following the
compiler suggestion here would cause a type unification error (since
`[]` doesn't unify with a 2-tuple).
Indeed, we mustn't render the Nil constructor when rendering non-empty
lists! So the correct suggestion should be:
```
[(_, True)]
```
We do not actually every parse negative values in there, as a negative value is a combination of a 'Negate' and 'UInt' expression.
However, for patterns and constant, it'll be simpler to parse whole Int values as there's no ambiguity with arithmetic operations
there. To avoid confusion of having some 'Int' constructors containing only non-negative values, and some being on the whole range,
I've renamed the constructor to 'UInt' to make this more obvious.