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new StackedMap(): StackedMap
Returns:<StackedMap>
< <K> , <V> >
Attributes
map:<Map>
< <K> , <InternalCell> < <V> >>
Returns the number of visible keys after collapsing the stack.
stack:<Map>
< <K> , <InternalCell> < <V> >>[]
asArray(): K[]
Returns:
{K[]}

Returns the visible keys as an array after collapsing the stack.


asMap(): Map
Returns:<Map>
< <K> , <Cell> < <V> >>

Returns the visible contents as a plain Map.


asPairArray(): Tuple
Returns:
<Tuple> < <K> , <Cell> < <V> >>[]

Returns visible key/value pairs using the external representation.


asSet(): Set
Returns:<Set>
< <K> >

Returns the visible keys as a Set after collapsing the stack.


createChild(): StackedMap
Returns:<StackedMap>
< <K> , <V> >

Creates a child StackedMap that sees the current layers as its parent scope.


delete(item): void

Deletes a key from the current view, either by removing it outright in the root layer or by recording a tombstone in child layers.


get(item): void
  • item {K}
  • Returns: <Cell><<V>>

Returns the visible value for a key, caching parent hits and misses in the current layer.


has(item): void

Checks whether a key exists in the current scope chain, caching any parent lookup result in the current layer.


set(item, value): void
  • item {K}
  • value {V}
  • Returns: <void>

Stores a value in the current layer, preserving explicit undefined values with an internal marker.

Type:<undefined> | <T>

Type:
<T> | <typeof TOMBSTONE> | <typeof UNDEFINED_MARKER>