Raven

Raven is a language server for R, Stan, and JAGS. Its defining idea: what's in scope depends on where your cursor is. Raven traces source() chains and resolves scope at your position, so completions, diagnostics, and navigation reflect what's actually defined when each line runs — across files, and within a single script (a variable defined on line 50 isn't in scope on line 10).

Because scope is resolved by position, Raven can flag genuinely undefined variables — and, parsing as you type, it catches parse errors (unclosed brackets, an else stranded from its }) and likely-bug patterns like mixed logical operators (a & b | c).

vscode-R (REditorSupport's R extension) is the established R extension for VS Code; Raven's language server runs alongside it, contributing cross-file, scope-aware code intelligence (plus RStudio-style indentation) on top of what you already have.

vscode-R's language intelligence comes from r-language-server, an R package that runs inside an R session and indexes the documents you have open (and, in an R package, its R/ directory). Raven is written in Rust to be fast, and needs no R session: it indexes your whole workspace and follows source() chains, so completions and navigation reach symbols in files you haven't opened — jump straight to a variable's definition in another file.

Raven is designed to complement, not replace, your existing tools. But it can run without vscode-R installed, if you want: then Raven uses its own R console, with data and plot viewers. Otherwise — if vscode-R is installed, or you're running inside Positron — those features stay off by default; they simply don't appear, so Raven leaves your existing setup untouched.

Features

Code intelligence

• Completions — Symbols, packages, and function parameters — across files
• Go-to-definition — Jump to definitions across file boundaries
• Find references — Locate all usages of a symbol across your project
• Hover — Symbol info including source file and package origin
• Diagnostics — Undefined variable detection that understands sourced files and loaded packages, plus opt-in style/lint rules
• Document outline — Hierarchical view with sections, classes, and nested functions
• Workspace symbols — Project-wide symbol search (Cmd/Ctrl+T)
• File path intellisense — Completions and cmd-click inside source() paths
• Smart indentation — Context-aware auto-indent with RStudio-style alignment
• Cross-file awareness — Follows source() chains to resolve scope across files
• Directives — Declare relationships and symbols the analyzer can't infer
• Syntax highlighting — R function names via LSP semantic tokens, plus JAGS and Stan syntax highlighting

Raven also provides lightweight support for JAGS (.jags, .bugs) and Stan (.stan) files: syntax highlighting, completions (keywords, distributions, file-local symbols), go-to-definition, find references, and document outline with model structure navigation.

R session integration

• R console — Interactive R console with statement detection and a temp-file fallback for large blocks; supports R, arf, and radian
• Code chunks — R Markdown / Quarto chunk detection with Run Chunk / Run Above / Run All commands, CodeLens buttons, navigation, and background highlighting; # %% cell support in .R files
• Knit Preview + Export — Raven: Knit Preview renders R Markdown to an HTML preview without requiring Pandoc; companion Export to HTML / PDF / Word commands save the result next to the .Rmd via Pandoc
• Plot viewer — Plots render in a VS Code panel via httpgd, with history navigation, save (PNG/SVG/PDF), and theme-aware background
• Data viewer — View(df) opens a virtualized grid backed by Apache Arrow; viewport-based rendering keeps scrolling responsive on multi-million-row frames
• Help viewer — Scope-aware R help: hovering shows the function in scope at the cursor instead of falling through to a multi-package list when scope can't be inferred

Settings

All settings live under the raven.* prefix. See the full configuration reference for the complete list.

Coexistence with vscode-R and Positron

Raven's R-console features (R console, plot viewer, data viewer) and vscode-R cover overlapping ground. By default raven.rConsole.activation is "auto", which leaves Raven's R-console features off when vscode-R is enabled or you're running inside Positron. Raven's help viewer and language server activate either way.

Raven ships its own opt-in style linter — a subset of lintr's rules re-implemented natively, with no R session or lintr install required. For lintr rules outside that subset, vscode-R's lintr diagnostics run from its own language server.

Two vscode-R settings (both default to true) let you trim that overlap:

• r.lsp.diagnostics — set to false to silence lintr while keeping vscode-R's session-based completions.
• r.lsp.enabled — set to false to shut vscode-R's language server down entirely. Use this when you only want vscode-R for its R-session features (console, viewers) and are happy to let Raven handle all code intelligence.

"r.lsp.diagnostics": false,   // keep vscode-R's LSP, drop only its lintr diagnostics
"r.lsp.enabled": false        // or: disable vscode-R's LSP entirely

For a deeper comparison see docs/comparison.md.

More Information

See the main repository for full documentation, including running the same analysis in CI with raven check, cross-file directives, editor integrations, and comparison with other R tools.

If you work with Stata, see Raven's sibling project, Sight, a Stata language server with the same cross-file awareness model.

License

GPL-3.0