Add Kotlin style Sequence Generators #616
Description
#e.g. with suspend and yield operators - note providing a BooleanSupplier indicates the suspended block should be executed until false (in this case infinitely).
int i = 100;
ReactiveSeq.generate(suspend(infinitely(),s->s.yield(i++)))
.take(6)
.printOut();
/**
100
101§
102
103
104
105
106
**/Execute the suspended block just once (itself meaningless unless we can also sequence actions)
int i = 100;
ReactiveSeq.generate(suspend(s->s.yield(i++)))
.take(6)
.printOut();
/**
100
**/Yield a sequence of values
ReactiveSeq.generate(suspend(times(10),s-> {
System.out.println("Top level - should repeat after sequence completes!");
return s.yield(1,
() -> s.yield(2),
() -> s.yield(3),
() -> s.yield(4));
}))
.take(6)
.printOut(); Support method references
Generator<Integer> generator = suspendRef(times(10),this::next);
generator.stream()
.forEach(System.out::println);
List<Integer> list = generator.to()
.linkedListX(LAZY)
.type(VavrTypes.list())
.map(this::process)
.to(VavrConverters::LIST);
public Integer next(){
return i++;
}
int i = 100;Method references directly during yielding
ReactiveSeq.generate(suspend(times(10),s-> {
System.out.println("Top level - should repeat after sequence completes!");
return s.yieldRef(1,
Generator::next,
Generator::next,
Generator::next,
Generator::next);
}
)).take(6)
.printOut();
public Integer next(){
return i++;
}More managable / complex mutable state via Inner Classes (if really needed)
ReactiveSeq.<Integer>generate(suspend(times(10),new ContFunction<Integer>() {
int runningTotal =0;
@Override
public Generator<Integer> apply(Suspended<Integer> s) {
System.out.println("Top level - should repeat after sequence completes!");
return s.yield(1,
() -> {
runningTotal = runningTotal +5;
return s.yield(runningTotal+2);
},
() -> s.yield(runningTotal+3),
() -> s.yield(runningTotal+6));
}
}
)).take(6)
.printOut();Control looping based on current value and support safe (s.maybe()) and unsafe (s.current()) to the current value.
ReactiveSeq.generate(suspend((Integer i)->i==4,s-> {
System.out.println("Top level - repeat infinetely after sequence (because we return 4!)");
return s.yield(1,
() -> s.yield(s.maybe()
.map(o->o+5)
.orElse(10)),
() -> s.yield(s.current()),
() -> s.yield(4));
}
)).take(120)
.printOut();