Add support for file and folder operations (create, rename, move) to workspace edits

[banacorn]

Instead of having TextDocumentEdit in WorkspaceEdit

data WorkspaceEdit =
  WorkspaceEdit
    { _changes         :: Maybe WorkspaceEditMap
    , _documentChanges :: Maybe (List TextDocumentEdit)
    } deriving (Show, Read, Eq)

It is now replaced by a new type called DocumentChange

data WorkspaceEdit =
  WorkspaceEdit
    { _changes         :: Maybe WorkspaceEditMap
    , _documentChanges :: Maybe (List DocumentChange)
    } deriving (Show, Read, Eq)

Which is just a synonym of union of WorkspaceEdit and other operations

type DocumentChange = TextDocumentEdit |? CreateFile |? RenameFile |? DeleteFile

So that it complies with the spec as suggested by @EggBaconAndSpam in #134 (comment)

---

Here's how to construct a DocumentChange that creates a file for example:

InR (InL (CreateFile FileResourceChangeCreate "/path/to/new/file" Nothing))

But it's a bit wordy and unsafe because of the FileResoureChangeKind.
I'm considering hiding these constructors and export only smart constructors.

[banacorn]

@bubba I should make a PR on lsp-test, right?
In that case, lsp-test would have to depend on this commit of lsp then 👀

[lukel97]

Hi @banacorn, thanks for this PR! Looks like there's a bit of a chicken and the egg situation with lap-types and lsp-test. You can create a branch on lsp-test for now and reference that commit in cabal.project, and then once this is merged we can merge the PRs for lsp-test

[lukel97]

Thanks, this is great! Just some minor nitpicks about the string literal tag. Out of curiosity, are you using this for your own language server?

[banacorn]

Yes, I'm building a language server for my toy language.
I have a button that exports all proof obligations to a new file, that's why I need this feature.

I'm planning on building a language server for Agda next.

[lukel97]

Whoops, looks like fix keyword in the PR message closes PRs across GitHub accounts

[lukel97]

LGTM now. Let me know when you're happy/referencing the new lsp-test commit and I'll merge

[lukel97]

Looks like its passing now. Want me to merge @banacorn ?

[banacorn]

Yes, please! Thank you!