Struct FormatterSpec 

pub struct FormatterSpec {
    pub program: &'static str,
    pub args: &'static [&'static str],
    pub filename_flag: Option<&'static str>,
}

How to invoke one external formatter.

Every formatter here reads the buffer on stdin and writes the result to stdout. That is deliberate and not merely convenient: a formatter that rewrites the file in place cannot be run against an unsaved buffer, and formatting only what is on disk is the wrong behaviour for an editor.

Fields

program: &'static str

Program name, resolved through PATH.

args: &'static [&'static str]

Fixed arguments.

filename_flag: Option<&'static str>

When set, the buffer’s path is appended as <flag>=<path>. Several formatters need the filename to pick a parser or find a config file even when reading stdin (prettier --stdin-filepath, clang-format --assume-filename).

Implementations

impl FormatterSpec

pub fn for_lang(lang: Lang) -> Option<Self>

The default formatter for lang, or None when there is no obvious choice.

This table is a starting point, not a contract. Formatter CLIs change flags across versions, and houses disagree about which formatter to use at all. Every entry is one line to correct, and formatprg overrides the whole thing per buffer. Absent entries are not gaps to be filled on principle — a language with no consensus formatter is better served by the user naming one.

pub fn parse(s: &str) -> Option<Self>

Parse a user-supplied formatter command line — an external: rung of a format.* chain (RF.5), or the deprecated formatprg.

Whitespace-split, first word is the program. Leaked to 'static because FormatterSpec holds &'static str for the built-in table’s sake; a handful of leaked option strings over a session is not a leak worth a lifetime parameter through the whole crate.

Returns None for an empty or whitespace-only string, which is the “not configured” signal rather than an error.

Trait Implementations

impl Clone for FormatterSpec

fn clone(&self) -> FormatterSpec

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FormatterSpec

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

Formats the value using the given formatter.

impl Eq for FormatterSpec

impl PartialEq for FormatterSpec

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for FormatterSpec