Retrieve the current definition of a key.
Retrieve the current definition of a key.
NoSuchElementException
when the key is undefined
in this environment.
Create a derived environment where key
is bound to
value
; previous bindings of key
are shadowed.
Create a derived environment where key
is bound to
value
; previous bindings of key
are shadowed.
Clear the binding for the given key.
Clear the binding for the given key. Lookups for key
will be
negative in the returned environment.
Tells whether key
is defined in this environment.
Tells whether key
is defined in this environment.
Retrieve the current definition of a key, but only if it is defined.
Retrieve the current definition of a key, but only if it is defined.
Retrieve the current definition of a key if it is defined.
Retrieve the current definition of a key if it is defined.
If it is not defined, orElse
is evaluated and returned.
A translucent environment is capable of storing key/value pairs to be (possibly) unmarshalled later.