Windows file URI is not handled properly. about vls

[SirZenith]

VSCode's approach of handling URI is to unescape everything that is escaped, and colon after drive name is escaped by default, see issue 75027 and issue 144698 of vscode.

As a reference, lua-language-server by sumneko escape most of the characters when generating URI on server side, see here. The escape pattern used [^%w%-%.%_%~%/] means everything that is no letter, number, -, ., _, ~, /.

I think VLS can use similar method. Escape most thing in file path. providing an normalized form of URI for language server to reference files.

I have finished URI encoding and decoding part on my fork.

[SirZenith]

And I propose VLS should use URI in normalized form for storing/fetching file information on server side.

Which is to first decode URI from client, and get file path from it no matter what the URI is. Then encode that file path with encoding function on VLS side. Referencing the target file with this URI made by VLS will make things more consistant.

And that requires adding method like

fn (du DocumentUri) normalize() DocumentUri {
    return document_uri_from_path(du.path())
}

and call it every time we need file information access on VLS side.

pub fn (mut ls Vls) did_open(params lsp.DidOpenTextDocumentParams, mut wr ResponseWriter) {
     uri := params.text_document.uri.normalize()
    // ...
   tree := ls.files[uri].tree
}

And this means everywhere in code that has a ls.files[uri] need to be fixed. That's a lots of work.