Struct Context 

pub struct Context {
    pub mappers: HashMap<TypeId, Box<Mapper>>,
}

Context for custom value transformations.

A context holds a collection of mappers keyed by the TypeId of the input type. When displaying a tree, the context is used to apply transformations to values before they are rendered.

Example

use tree_display::Context;

let context = Context::new()
    .map(|s: &String| format!("'{}'", s))
    .map(|n: &i32| format!("{}", n * 2));

Fields

mappers: HashMap<TypeId, Box<Mapper>>

Map from TypeId to a mapper function for that type.

Implementations

impl Context

pub fn new() -> Self

Creates a new empty context with no mappers.

pub fn map<T: 'static, R: Content + 'static>( self, f: impl Fn(&T) -> R + 'static, ) -> Self

Registers a mapper for a specific type.

The mapper function takes a reference to a value and returns another value that implements Content. The transformed value will be used when displaying values of type T in the tree.

To apply a mapper to a specific field in a struct or enum, use the #[tree(map)] attribute on that field when deriving TreeDisplay.

Type Parameters

• T: The input type to map from
• R: The output type that implements Content

Example

use tree_display::context::Context;

let context = Context::new()
    .map(|s: &String| format!("'{}'", s))
    .map(|n: &i32| format!("{}", n * 2));

Trait Implementations

impl Default for Context

fn default() -> Context

Returns the “default value” for a type.