java.lang.Object
com.jnape.palatable.lambda.functions.builtin.fn2.GroupBy<K,V>
Type Parameters:
K - the Map key type
V - the Map value type
All Implemented Interfaces:
Fn1<Fn1<? super V,? extends K>,Fn1<Iterable<V>,Map<K,List<V>>>>, Fn2<Fn1<? super V,? extends K>,Iterable<V>,Map<K,List<V>>>, Applicative<Fn1<Iterable<V>,Map<K,List<V>>>,Fn1<Fn1<? super V,? extends K>,?>>, Cartesian<Fn1<? super V,? extends K>,Fn1<Iterable<V>,Map<K,List<V>>>,Fn1<?,?>>, Cocartesian<Fn1<? super V,? extends K>,Fn1<Iterable<V>,Map<K,List<V>>>,Fn1<?,?>>, Contravariant<Fn1<? super V,? extends K>,Profunctor<?,Fn1<Iterable<V>,Map<K,List<V>>>,Fn1<?,?>>>, Functor<Fn1<Iterable<V>,Map<K,List<V>>>,Fn1<Fn1<? super V,? extends K>,?>>, Profunctor<Fn1<? super V,? extends K>,Fn1<Iterable<V>,Map<K,List<V>>>,Fn1<?,?>>, Monad<Fn1<Iterable<V>,Map<K,List<V>>>,Fn1<Fn1<? super V,? extends K>,?>>, MonadReader<Fn1<? super V,? extends K>,Fn1<Iterable<V>,Map<K,List<V>>>,Fn1<Fn1<? super V,? extends K>,?>>, MonadRec<Fn1<Iterable<V>,Map<K,List<V>>>,Fn1<Fn1<? super V,? extends K>,?>>, MonadWriter<Fn1<? super V,? extends K>,Fn1<Iterable<V>,Map<K,List<V>>>,Fn1<Fn1<? super V,? extends K>,?>>

public final class GroupBy<K,V> extends Object implements Fn2<Fn1<? super V,? extends K>,Iterable<V>,Map<K,List<V>>>
Given an Iterable<V> vs and a key function V -> K f, fold vs into a Map<K, List<V>> by applying f to each element of vs, retaining values that map to the same key in a list, in the order they were iterated in.
See Also:
  • Field Details

    • INSTANCE

      private static final GroupBy<?,?> INSTANCE
  • Constructor Details

    • GroupBy

      private GroupBy()
  • Method Details