Note: This site is currently "Under construction". I'm migrating to a new version of my site building software. Lots of things are in a state of disrepair as a result (for example, footnote links aren't working). It's all part of the process of building in public. Most things should still be readable though.

rust-analyzer JSON-RPC Initialization Call From Neovim

I'm working on a process to use rust-analyzer to do syntax highlighting for my neopolitan document format. The analyzer operates over STDIN with JSON-RCP. I figured out how to get things connected, but wasn't getting syntax highlighting. I built a little app to watch what Neovim uses for connection to see if that shows anything. This is what it captured.

Code

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{"id":1,"params":{"trace":"off","workspaceFolders":[{"uri":"file:\/\/\/Users\/alan\/Desktop\/ratest","name":"\/Users\/alan\/Desktop\/ratest"}],"rootUri":"file:\/\/\/Users\/alan\/Desktop\/ratest","rootPath":"\/Users\/alan\/Desktop\/ratest","clientInfo":{"name":"Neovim","version":"0.9.1"},"capabilities":{"workspace":{"workspaceFolders":true,"applyEdit":true,"workspaceEdit":{"resourceOperations":["rename","create","delete"]},"symbol":{"hierarchicalWorkspaceSymbolSupport":true,"dynamicRegistration":false,"symbolKind":{"valueSet":[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26]}},"semanticTokens":{"refreshSupport":true},"configuration":true,"didChangeWatchedFiles":{"dynamicRegistration":false,"relativePatternSupport":true}},"window":{"showDocument":{"support":true},"workDoneProgress":true,"showMessage":{"messageActionItem":{"additionalPropertiesSupport":false}}},"experimental":{"serverStatusNotification":true},"textDocument":{"definition":{"linkSupport":true},"documentHighlight":{"dynamicRegistration":false},"references":{"dynamicRegistration":false},"signatureHelp":{"dynamicRegistration":false,"signatureInformation":{"parameterInformation":{"labelOffsetSupport":true},"documentationFormat":["markdown","plaintext"],"activeParameterSupport":true}},"codeAction":{"dynamicRegistration":false,"dataSupport":true,"isPreferredSupport":true,"resolveSupport":{"properties":["edit"]},"codeActionLiteralSupport":{"codeActionKind":{"valueSet":["","quickfix","refactor","refactor.extract","refactor.inline","refactor.rewrite","source","source.organizeImports"]}}},"hover":{"dynamicRegistration":false,"contentFormat":["markdown","plaintext"]},"rename":{"dynamicRegistration":false,"prepareSupport":true},"callHierarchy":{"dynamicRegistration":false},"declaration":{"linkSupport":true},"implementation":{"linkSupport":true},"publishDiagnostics":{"relatedInformation":true,"tagSupport":{"valueSet":[1,2]}},"completion":{"dynamicRegistration":false,"contextSupport":true,"completionList":{"itemDefaults":["commitCharacters","editRange","insertTextFormat","insertTextMode","data"]},"completionItem":{"commitCharactersSupport":true,"snippetSupport":true,"deprecatedSupport":true,"resolveSupport":{"properties":["documentation","detail","additionalTextEdits","sortText","filterText","insertText","textEdit","insertTextFormat","insertTextMode"]},"documentationFormat":["markdown","plaintext"],"tagSupport":{"valueSet":[1]},"insertReplaceSupport":true,"labelDetailsSupport":true,"insertTextModeSupport":{"valueSet":[1,2]},"preselectSupport":true},"completionItemKind":{"valueSet":[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25]},"insertTextMode":1},"synchronization":{"didSave":true,"willSaveWaitUntil":true,"dynamicRegistration":false,"willSave":true},"semanticTokens":{"dynamicRegistration":false,"tokenModifiers":["declaration","definition","readonly","static","deprecated","abstract","async","modification","documentation","defaultLibrary"],"multilineTokenSupport":false,"overlappingTokenSupport":true,"augmentsSyntaxTokens":true,"serverCancelSupport":false,"requests":{"range":false,"full":{"delta":true}},"tokenTypes":["namespace","type","class","enum","interface","struct","typeParameter","parameter","variable","property","enumMember","event","function","method","macro","keyword","modifier","comment","string","number","regexp","operator","decorator"],"formats":["relative"]},"documentSymbol":{"dynamicRegistration":false,"hierarchicalDocumentSymbolSupport":true,"symbolKind":{"valueSet":[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26]}},"typeDefinition":{"linkSupport":true}}},"initializationOptions":{},"processId":88229},"method":"initialize","jsonrpc":"2.0"}

Note

I'm not formatting that right now because when I did it in VSCode it removed the leading `\`` from the slashes.

References

  • This is the simple little tool I built to capture the STDIN Neovim sends to rust-analyzer. I simply did a quick switch to rename it to "rust-analyzer" and fired up Neovim to capture the output. One I had it I put the real one back in place.