Enum FormatStyle 

pub enum FormatStyle {
    Display,
    Debug,
}

Which of the two renderings a format callback is producing.

Exactly one type reads this — Text — and it is one bit rather than a second callback per descriptor because of nesting: a Vec[Text] renders its elements through the element descriptor’s format, so whatever distinguishes the two renderings has to travel down that recursion. A format_debug field beside format would not: vec_format would have to know which of the two it was itself running as in order to pick the right one for its elements, and that knowledge is exactly this enum.

Variants

Display

The program’s own rendering: out(v), "{v}" interpolation, to_text() and praxis run’s result line. A Text is its characters, because that is what a program printing a string means (§16.1, and §8.1 for the interpolation that shares the callback).

Debug

The debugger’s rendering: a locals row, a TUI pane cell, p EXPR. A Text is a quoted literal here, because a display that gives each value one line and no other context cannot afford a value that renders as zero characters, as a newline, or as something an adjacent " could have ended.

Trait Implementations

impl Clone for FormatStyle

fn clone(&self) -> FormatStyle

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for FormatStyle

impl Debug for FormatStyle

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

Formats the value using the given formatter.

impl Eq for FormatStyle

impl PartialEq for FormatStyle

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for FormatStyle