Enum FormatProvider 

pub enum FormatProvider {
    Native,
    Lsp,
    LangDefault,
    External(String),
    Plugin(String),
}

One rung of a ProviderChain.

The set is open at the edges (External, Plugin) and closed in the middle, which is what lets parse reject a typo like nativ while still admitting formatters the editor has never heard of.

Variants

Native

The built-in engine for the intent: the tree-sitter indent engine for indent, the textwidth reflow engine for reflow. Not meaningful for reformat, where it resolves to nothing and the chain moves on.

Lsp

textDocument/formatting or rangeFormatting from an attached server.

Eligible in any chain, default only in reformat. The protocol has no indent-only and no reflow request, so putting this in indent or reflow gets you a reformat — which is a legitimate thing to want and a bad default, because in the common case (rustfmt’s wrap_comments is off by default, prettier’s proseWrap defaults to preserve) it silently does nothing to a comment paragraph. text-reflow.md §5.

LangDefault

The built-in per-language formatter table (lattice_format::FormatterSpec::for_lang) — rustfmt, prettier, black, gofmt and peers, each probed on PATH and skipped when absent.

External(String)

A user-named external filter, as a command line: external:prettier --stdin-filepath %. The replacement for formatprg, and for the equalprg that was never implemented.

Plugin(String)

A formatter contributed by a WASM plugin, by id.

Implementations

impl FormatProvider

pub fn label(&self) -> String

Canonical string form. Round-trips with Self::parse.

pub fn parse(s: &str) -> Result<Self, String>

Parse one rung.

The prefixed forms carry a payload; the bare forms are a closed set, so an unrecognised bare word is an error rather than being silently taken for an external command. That distinction is the point of the external: prefix existing at all — without it, :set format.reformat=nativ would install a chain that tries to run a program called nativ.

Trait Implementations

impl Clone for FormatProvider

fn clone(&self) -> FormatProvider

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for FormatProvider

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for FormatProvider

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for FormatProvider

impl PartialEq for FormatProvider

fn eq(&self, other: &FormatProvider) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for FormatProvider