Struct Environment

pub struct Environment<Name: Eq + Hash, T> { /* private fields */ }

A scoped set of bindings between names and values.

Implementations

impl<Name: Eq + Hash, T> Environment<Name, T>

pub fn new() -> Self

Constructs a new context with a base scope that further scopes can be pushed and popped on top of.

pub fn push(&mut self)

Creates a new scope.

pub fn pop(&mut self) -> bool

Removes all bindings in the most recent scope, returning true unless there are no scopes beside the base scope.

pub fn bind(&mut self, name: Name, value: T) -> Option<T>

Binds name to value in the top scope, returning Some(previous_value) if previous_value had previously been bound to name, or None.

pub fn bind_base(&mut self, name: Name, value: T) -> Option<T>

Binds name to value in the base scope.

@see Environment::bind

pub fn find(&self, name: Name) -> Option<&T>

Finds the bound value for name in the highest scope possible.

Trait Implementations

impl<Name: Eq + Hash, T> Default for Environment<Name, T>

fn default() -> Self

Returns the “default value” for a type.