The LSP spec requires us to omit keys for nil values rather than using
the JSON `null` constant in most places. This change to CustomCodable
allows us to do it automatically using CustomCodable, removing one of
the limitations of the property wrapper.
The idea for the adding overloads of `encode` and `decode` came from
https://forums.swift.org/t/pre-pitch-codable-customization-using-propertywrappers/30244/
Not all editors send shutdown/exit messages, particularly when you quit
the application (as opposed to a single editor window), so we sprinkle
`prepareForShutdown()` into the connection closed handler as well. I
verified manually in such an editor that this lets us save the index on
quit.
Since the connection and message handler have a reciprocal need to know
about each other, move the closeHandler so that it has the opportunity
to call a method on the message handler if desired.
If the client is well-behaved and sends a shutdown request, we close the
index in order to flush it to disk. This should speed up reopening the
same project when it is already indexed.
URL can in fact store URIs, it just doesn't have a very nice API to
interact with them. As long as we only operate on absoluteString, we
should be fine though. So instead of implementing the logic for
detecting file URLs ourselves, we can just use a URL as storage for
DocumentURI.
In the fallback build system use the URIs pseudo path to construct
compiler arguments. For non-file URIs this means passing the raw URI as
the filename. We were already testing non-existing file-URLs like /a.txt
and arbitrary URIs seem to allow semantic functionality as well.
According to the LSP specification, arbitrary URIs can be used as
document identifiers. Instead of internally assuming that all URIs are
URLs, use a DocumentURI enum to represent URIs. These can either be file
URLs or other URIs whose value as treated as an opaque string.
We will be able to split the LSP modules off later. These LSP modules
will provide the ability to write custom LSP servers and clients in
Swift. The sourcekit-lsp repository will build on top of this new
package to provide an LSP implementation that creates a language server
for Swift and C-based-languages.
Apart from removing unnecessary imports, the following changes were
performed:
- Move CancellationToken from SKSupport to LanguageServerProtocol
- Move CustomCodable to its own module
- CustomCodable belongs in LanguageServerProtocol but moving it there
causes compilation to fail. As a workaround, move it to its own
module
- Clangd uses the HierarchicalDocumentSymbolSupport field of the
documentSymbol capabilities, if we don't pass it through clangd
will change its behavior potentially resulting in a response
error (e.g. in Visual Studio Code)
