Struct EnvMap 

pub struct EnvMap<K, V> { /* private fields */ }

EnvMap is a wrapper of HashMap, but with the ability to backtrack and recover from modification

Implementations

impl<K, V> EnvMap<K, V>

where K: Eq + Hash + Clone,

pub fn new() -> EnvMap<K, V>

Creating an empty EnvMap

pub fn with_capacity(capacity: usize) -> EnvMap<K, V>

Creating an empty EnvMap with capacity

pub fn capacity(&self) -> usize

Returns the number of elements the map can hold without reallocating.

pub fn keys(&self) -> Keys<'_, K, V>

An iterator visiting all keys in arbitrary order.

pub fn values(&self) -> Values<'_, K, V>

An iterator visiting all values in arbitrary order.

pub fn iter(&self) -> Iter<'_, K, V>

An iterator visiting all key-value pairs in arbitrary order.

pub fn is_empty(&self) -> bool

Returns true if the map contains no elements.

pub fn is_scope_empty(&self) -> bool

Returns true if there is no saved scope frame

pub fn clear(&mut self)

Clears the map, removing all key-value pairs. Keeps the allocated memory for reuse.

pub fn get<Q>(&self, k: &Q) -> Option<&V>

where K: Borrow<Q>, Q: ?Sized + Hash + Eq,

Returns a reference to the value corresponding to the key.

pub fn get_key_value<Q>(&self, k: &Q) -> Option<(&K, &V)>

where K: Borrow<Q>, Q: ?Sized + Hash + Eq,

Returns the key-value pair corresponding to the supplied key.

pub fn contains_key<Q>(&self, k: &Q) -> bool

where K: Borrow<Q>, Q: ?Sized + Hash + Eq,

Returns true if the map contains a value for the specified key.

pub fn insert(&mut self, k: K, v: V) -> bool

Inserts a key-value pair into the map.

pub fn remove(&mut self, k: &K) -> bool

Removes a key from the map

pub fn enter_scope(&mut self)

Enter a new scope, record the current pivot of history

pub fn leave_scope(&mut self)

Leave from a scope, unwind the history and recover.

Trait Implementations

impl<K: Clone, V: Clone> Clone for EnvMap<K, V>

fn clone(&self) -> EnvMap<K, V>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<K: Debug, V: Debug> Debug for EnvMap<K, V>

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

Formats the value using the given formatter.

impl<K, V> Default for EnvMap<K, V>

where K: Eq + Hash + Clone,

Many implementations are just the same as HashMap

fn default() -> Self

Returns the “default value” for a type.

impl<K, V> Index<&K> for EnvMap<K, V>

where K: Hash + Eq,

type Output = V

The returned type after indexing.

fn index(&self, index: &K) -> &Self::Output

Performs the indexing (container[index]) operation.