Trait Scope

pub trait Scope: Sized {
    type Errors: ErrorAccumulator;
    type Indent: IndentTracker;

    // Required methods
    fn indent(&self) -> impl Display;
    fn push_indent(&self) -> Self;
    fn options(&self) -> &OutputOptions;
    fn extensions(&self) -> &SimpleExtensions;
    fn errors(&self) -> &Self::Errors;

    // Provided methods
    fn push_error(&self, e: FormatError) { ... }
    fn failure<E: Into<FormatError>>(&self, e: E) -> ErrorToken { ... }
    fn expect<'a, T: Textify>(
        &'a self,
        t: Option<&'a T>,
    ) -> MaybeToken<impl Display> { ... }
    fn expect_ok<'a, T: Textify, E: Into<FormatError>>(
        &'a self,
        result: Result<&'a T, E>,
    ) -> MaybeToken<impl Display + 'a> { ... }
    fn display<'a, T: Textify>(
        &'a self,
        value: &'a T,
    ) -> Displayable<'a, Self, T> { ... }
    fn separated<'a, T: Textify, I: IntoIterator<Item = &'a T> + Clone>(
        &'a self,
        items: I,
        separator: &'static str,
    ) -> Separated<'a, Self, T, I> { ... }
    fn option<'a, T: Textify>(
        &'a self,
        value: Option<&'a T>,
    ) -> OptionalDisplayable<'a, Self, T> { ... }
    fn optional<'a, T: Textify>(
        &'a self,
        value: &'a T,
        option: bool,
    ) -> OptionalDisplayable<'a, Self, T> { ... }
}

Holds the context for outputting a plan.

This includes:

• Options (&OutputOptions) for formatting
• Errors (&ErrorAccumulator) for collecting errors
• Extensions (&SimpleExtensions) for looking up function and type names
• Indent (&IndentTracker) for tracking the current indent level

The Scope trait is used to provide the context for textifying a plan.

Required Associated Types

type Errors: ErrorAccumulator

The type of errors that can occur when textifying a plan.

type Indent: IndentTracker

Required Methods

fn indent(&self) -> impl Display

Get the current indent level.

fn push_indent(&self) -> Self

Push a new indent level.

fn options(&self) -> &OutputOptions

Get the options for formatting the plan.

fn extensions(&self) -> &SimpleExtensions

fn errors(&self) -> &Self::Errors

Provided Methods

fn push_error(&self, e: FormatError)

fn failure<E: Into<FormatError>>(&self, e: E) -> ErrorToken

Handle a failure to textify a value. Textify errors are written as “!{name}” to the output (where “name” is the type name), and the error is pushed to the error accumulator.

fn expect<'a, T: Textify>( &'a self, t: Option<&'a T>, ) -> MaybeToken<impl Display>

fn expect_ok<'a, T: Textify, E: Into<FormatError>>( &'a self, result: Result<&'a T, E>, ) -> MaybeToken<impl Display + 'a>

fn display<'a, T: Textify>(&'a self, value: &'a T) -> Displayable<'a, Self, T>

fn separated<'a, T: Textify, I: IntoIterator<Item = &'a T> + Clone>( &'a self, items: I, separator: &'static str, ) -> Separated<'a, Self, T, I>

Wrap an iterator over textifiable items into a displayable that will separate them with the given separator.

Example

let items = vec![1, 2, 3];
let separated = self.separated(&items, ", ");

fn option<'a, T: Textify>( &'a self, value: Option<&'a T>, ) -> OptionalDisplayable<'a, Self, T>

fn optional<'a, T: Textify>( &'a self, value: &'a T, option: bool, ) -> OptionalDisplayable<'a, Self, T>

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl<'a, Err: ErrorAccumulator> Scope for ScopedContext<'a, Err>

type Errors = Err

type Indent = IndentStack<'a>