xlflow lsp
Start the reusable VBA language server for editor integrations.
Usage
xlflow lsp --stdio
xlflow lsp --stdio --log-file .xlflow/lsp.log
xlflow lsp --check
xlflow lsp --versionOptions and Arguments
| Option / argument | Description | Default |
|---|---|---|
--stdio | Run the LSP server over standard input/output JSON-RPC. | false |
--check | Validate server dependencies without starting JSON-RPC. | false |
--version | Print LSP server build metadata. | false |
--log-file | Write server logs to this file instead of standard error. | stderr |
Exactly one of --stdio, --check, or --version is required.
Notes
xlflow lsp --stdio reserves stdout exclusively for LSP messages. Normal logs go to stderr unless --log-file is provided.
xlflow lsp --check works even before a project has an xlflow.toml; it validates the parser and built-in type database using default configuration.
When the global generated TypeLib database is missing or stale, xlflow lsp --stdio and xlflow lsp --check attempt best-effort generation before loading the database. Generation failures are reported on stderr and do not prevent the LSP from starting with the embedded built-in database.
The MVP server supports full document synchronization, diagnostics, semantic tokens, document symbols, workspace symbols, definition lookup, references, prepare rename, rename, hover, completion, signature help, document formatting, and CodeLens. Open editor buffers are authoritative over saved filesystem content until the editor sends textDocument/didClose.
Rename support is conservative and scope-aware. It works for high-confidence VBA source symbols such as local variables, parameters, procedure-local constants, private module-level variables/constants, same-module private procedures, and same-procedure labels used by GoTo, GoSub, Resume, or On Error GoTo. It refuses host object model members, TypeLib/external members, public project-wide APIs, module files, Attribute VB_Name, UserForm controls, event handlers, property groups, ambiguous names, and unresolved identifiers.
Diagnostics reuse xlflow's file-local VBA lint rules against the current in-memory editor buffer and publish stable VB... codes with source="xlflow". Project-wide and filesystem-only lint checks remain available through xlflow lint.
The LSP also publishes editor-first argument diagnostics such as VB030 for missing required arguments, excessive arguments, and unknown named arguments when the target signature is known from project symbols or the built-in VBA/COM database. These diagnostics are intentionally LSP-only for now and are not yet part of the xlflow lint CLI contract.
The built-in VBA/COM database includes practical Excel, MSForms, Scripting, ADODB, VBIDE, Office, and VBA constant metadata for hover, completion, and basic type inference.
Semantic tokens are provided by the Go language server with full-document textDocument/semanticTokens/full responses. They classify VBA declarations, parameters, variables, built-in types, globals, constants, member expressions, comments, strings, numbers, operators, and keywords. Range and delta semantic token requests are not advertised yet.
CodeLens is provided through textDocument/codeLens with resolveProvider=false. The server returns $(play) Run for runnable no-argument Sub procedures and $(beaker) Run Test for no-argument test procedures named Test*, test*, or *_Test; VS Code renders those $(...) prefixes as codicons. Function, Property, Declare, and argument-bearing procedures are intentionally excluded. UserForm event-style procedures are hidden by default unless the editor passes initializationOptions.codeLens.userFormEvents=true.
For UserForms, xlflow reads tracked .frm files and extracts design-time controls for code intelligence. Controls such as txtName in Me.txtName.Text and Me.Controls("txtName").Text can participate in hover, completion, and definition lookup without opening Excel.
VS Code Client
The VS Code extension should launch xlflow as a thin language client:
serverOptions = {
command: "xlflow",
args: ["lsp", "--stdio"],
};For the MVP, xlflow is resolved from PATH.