Functors are data structures that support lazy mapping through an instance of
fmap .
ExamplesUSING: math monadics prettyprint quotations ;
6 just [ 1 + ] fmap .
T{ Just { value 7 } }
Values that cannot return a single value immediately are "thunked" as curried quotations:
USING: combinators math monadics sequences prettyprint quotations ;
{ 1 2 3 } [ + ] fmap .
{ [ 1 + ] [ 2 + ] [ 3 + ] }
For details on this vocabulary's implementation of lazyness:
Monadic Implementation Quirks .