Struct FormatSink 

pub struct FormatSink<'a> { /* private fields */ }

The writer a format callback appends to, carrying the FormatStyle it is rendering under.

A wrapper rather than an extra parameter, so that a container passing its writer to an element descriptor passes the style with it and cannot forget to.

Implementations

impl<'a> FormatSink<'a>

pub fn display(out: &'a mut dyn Write) -> FormatSink<'a>

A sink in the program’s own rendering.

pub fn debug(out: &'a mut dyn Write) -> FormatSink<'a>

A sink in the debugger’s rendering.

pub fn style(&self) -> FormatStyle

The style this sink renders under.

pub fn styled(out: &'a mut dyn Write, style: FormatStyle) -> FormatSink<'a>

A sink over out in a style read off another one.

For the callbacks that render a part into a scratch String before placing it — map_format orders its entries by key and has to have them rendered to place them (ADR-138 decision 4). Such a callback holds its style across the buffer and rebuilds a sink around it, which is what keeps a Map[Text, Text] quoting its keys and values in the debugger, exactly as a Vec[Text] does without needing a buffer at all.

Every scratch buffer is a place the style could be dropped, and dropping it is silent — the value still renders, just in the other rendering. The style is Copy so that carrying it across is the easy thing to write.

Trait Implementations

impl Write for FormatSink<'_>

fn write_str(&mut self, s: &str) -> Result

Writes a string slice into this writer, returning whether the write succeeded.

fn write_char(&mut self, c: char) -> Result<(), Error>

Writes a char into this writer, returning whether the write succeeded.

fn write_fmt(&mut self, args: Arguments<'_>) -> Result<(), Error>

Glue for usage of the write! macro with implementors of this trait.