LSP Features

LSP methods spice-lsp implements or plans to implement, organized by release phase. MVP ships only syntax sync and diagnostics; richer behavior accumulates in later versions.

Capability matrix

Full specification of reference hover and net diagnostics: Dialect reference and net semantics.

MVP

Server capabilities

{
  "capabilities": {
    "textDocumentSync": {
      "openClose": true,
      "change": 2,
      "save": false
    }
  },
  "serverInfo": { "name": "spice-lsp", "version": "0.1.0" }
}

change: 2 is Incremental sync — the client sends edit ranges, not the full buffer every keystroke.

Diagnostics arrive via server-initiated textDocument/publishDiagnostics.

Syntax diagnostics

v0.2 — Symbols and light semantics

Server capabilities

Adds outline and navigation on top of MVP sync:

{
  "capabilities": {
    "textDocumentSync": { "openClose": true, "change": 2 },
    "documentSymbolProvider": true,
    "definitionProvider": true,
    "referencesProvider": true
  }
}

Document symbols for outline / breadcrumbs:

Navigation: go to definition and find references for subcircuits, models, and parameters. textDocument/references honors context.includeDeclaration (omit definition sites when the client passes false).

Diagnostics:

Diagnostics from didChange are debounced (~150 ms) so rapid typing does not re-analyze on every keystroke. didOpen publishes immediately. Navigation handlers refresh the in-memory index on demand.

v0.3 — Completion and file-local hover

Completion contexts: element letters, directive names, in-scope model and subcircuit names, snippet templates for .tran / .subckt.

Hover (file-local only): subcircuit port order, parameters from .model / .subckt in the open buffer. No curated reference yet — that is v0.5.

Dialect selection (issue #16)

spiceLsp.dialect is hspice | ngspice | ltspice (default hspice). The VS Code command SPICE LSP: Set Dialect… and a status-bar item change it. The same dialect selects the reference corpus for hover and (later) completion docs.

Design: Multi-dialect support.

Hover

textDocument/hover resolves in order:

1. Curated entry from reference/ for the active dialect (_shared fallback)
2. File-local detail for .subckt / .model / .param symbols
3. No hover

v0.4 — Formatting

Registers documentFormattingProvider. Formatter profiles may follow the active dialect later.

See Formatter.

v0.5 — Dialect reference hover and net connectivity

Reference-powered hover

When the cursor is on a directive, option, element keyword, or documented expression form, the server loads the matching entry from reference/<dialect>/ and returns markdown:

• Summary and syntax
• Parameter table with units
• Examples and seeAlso links

You maintain this corpus over time; the LSP only indexes and renders it. Authoring guide: Dialect reference and net semantics.

Connectivity diagnostics

Published alongside syntax diagnostics in publishDiagnostics. Configurable via spiceLsp.diagnostics.* settings.

Client configuration

Testing

Each phase adds integration tests for newly advertised capabilities. MVP priorities:

1. initialize returns expected capabilities
2. Open invalid document → diagnostics notification
3. Edit → updated diagnostics

v0.2 adds:

4. documentSymbol returns hierarchical outline for .subckt blocks

5. definition on subcircuit reference jumps to .subckt definition

6. references on subcircuit definition lists definition + usages; includeDeclaration: false omits the definition

7. Semantic fixtures (duplicate-instance.cir, unknown-subckt.cir) produce warning codes

8. Rapid didChange events coalesce into a single diagnostics publish after the debounce window

9. (v0.5) Open semantic fixture → dangling / floating warnings; hover snapshot matches reference entry

See Demo and testing.