Predicates

Predicates

Predicates defines a number of predicates for filtering cyclops-react data structures and for pattern matching.

Examples

We can use Predicates to filter a Stream

import static com.aol.cyclops.util.function.Predicates.greaterThan;
   
Stream.of(1,2,3,100,200,300)
      .filter(greaterThan(10));
  
//Stream[100,200,300]

Predicates compose

import static com.aol.cyclops.util.function.Predicates.*;

ReactiveSeq.of(1,2,3).filter(anyOf(not(in(2,3,4)),in(1,10,20)));

ListX.of(1,2,3).filter(anyOf(not(greaterThan(2)),in(1,10,20)));

PStackX.of(1,2,3).filter(anyOf(not(greaterThanOrEquals(2)),in(1,10,20)));

QueueX.of(1,2,3).filter(anyOf(not(lessThan(2)),in(1,10,20)));

ReactiveSeq.of(1,2,3).filter(anyOf(not(lessThanOrEquals(2)),in(1,10,20)));

ReactiveSeq.of(1,2,3).filter(anyOf(not(eq(2)),in(1,10,20)));

Stream.of(Maybe.of(2)).filter(eqv(Eval.now(2)));

Maybe.just(2).filter(eqv(Eval.later(()->2)); //Maybe[2]

We can use Predicates when Pattern Matching

import static com.aol.cyclops.control.Matchable.otherwise;
import static com.aol.cyclops.control.Matchable.then;
import static com.aol.cyclops.control.Matchable.when;
import static com.aol.cyclops.util.function.Predicates.*;

Matchables.match2(100,2)
          .matches(c->c.is(when(Predicates.greaterThan(50),Predicates.lessThan(10)), ()->"large and small"), ()->"not large and small")
          .get();
//"large and small"

Matchables.url(new URL("http://www.aol.com/path?q=hello"))
                                     .on$12_45()
                                     .matches(c->c.is(when(eq("http"),in("www.aol.com","aol.com"),any(),not(eq("q=hello!"))), then("correct")),otherwise("miss"));
       
//Eval["correct"]