Optional<T> extension

on

Properties

isEmpty → bool: Available on T?, provided by the Optional extension
returns true if value is not null.
no setter

filter(bool f(T)) → T?: Available on T?, provided by the Optional extension
returns if value is not empty and matches given function f.
flatMap<R>(R f(T)) → R?: Available on T?, provided by the Optional extension
returns some value if both this and returned value of function f are some.
fold<R>(R ifEmpty()) → R Function(R (T)): Available on T?, provided by the Optional extension
returns value returned from ifEmpty thunk if value is null. otherwise, returns value gained from applying function f to this value.
foreach(void f(T)) → void: Available on T?, provided by the Optional extension
do side-effect operation if this value is not empty
getOrElse(T els()) → T: Available on T?, provided by the Optional extension
returns value if value is not null, else returns given els value.
map<R>(R f(T)) → R?: Available on T?, provided by the Optional extension
map value using function f if value is not null.
mapOr<R>(R f(T), {required R or}) → R: Available on T?, provided by the Optional extension
toList() → List<T>: Available on T?, provided by the Optional extension
convert optional value into list of length 0 or 1.