Code intelligence

Language support, language servers, completion, folding, and the build/error loop.

TopicWhat it covers
LanguagesBundled languages, coverage roadmap, and how to add a new language (tree-sitter or otherwise).
Language Server Protocol (LSP)LSP integration: servers, capabilities, attach lifecycle, diagnostics, every :lsp-* command in context.
The lsp-mode gatePer-buffer gate that controls whether LSP features run (auto-activation, toggle, what's gated, programmatic API).
Insert-mode completionInsert-mode completion: triggers, sources, popup keymap, configuration, troubleshooting.
FoldingManual + computed folds, fold operators, navigation, auto-open on search.
Compilation:compile runs any CLI tool, streams its output into compilation, and parses file:line:col references into the error list; gr recompiles, jumps, :problems groups the results.
ProjectsEvery buffer belongs to a project, found by walking up for a marker like .git or Cargo.toml; :project-root reports it and the marker that decided it, and project.root-markers configures the list.
The error listThe error list: a navigable list of file:line:col locations walked with :next-error/:previous-error (]qq/[qq) — populated by :compile (any CLI tool), browsed with :error-list, grouped with :problems.