@Test
public void flatMapChain() {
assertEquals(
Sequence.emptySequence(),
Sequence.of(1, 2, 3, 4, 5, 6, 7, 8, 9)
.flatMap(emptySeqFunc)
.flatMap(emptySeqFunc)
.flatMap(emptySeqFunc));
assertEquals(
Sequence.emptySequence(),
Sequence.emptySequence().flatMap(identSeqFunc).flatMap(identSeqFunc).flatMap(identSeqFunc));
assertArrayEquals(
new Integer[] {},
Sequence.of(1, 2, 3, 4, 5, 6, 7, 8, 9)
.flatMap(emptySeqFunc)
.flatMap(emptySeqFunc)
.flatMap(emptySeqFunc)
.toTypedArray());
assertArrayEquals(
new Integer[] {1, 2, 2, 3, 3, 4, 10, 11, 20, 21, 30, 31},
Sequence.of(1, 10)
.flatMap(i -> Sequence.of(i, i * 2, i * 3))
.flatMap(i -> Sequence.of(i, i + 1))
.toTypedArray());
}
@Test
public void singleFlatMap() {
assertEquals(
Sequence.emptySequence(), Sequence.of(1, 2, 3, 4, 5, 6, 7, 8, 9).flatMap(emptySeqFunc));
assertEquals(Sequence.emptySequence(), Sequence.emptySequence().flatMap(identSeqFunc));
assertArrayEquals(
new Integer[] {},
Sequence.of(1, 2, 3, 4, 5, 6, 7, 8, 9).flatMap(emptySeqFunc).toTypedArray());
assertArrayEquals(
new Integer[] {
1, 2, 3, 2, 4, 6, 3, 6, 9, 4, 8, 12, 5, 10, 15, 6, 12, 18, 7, 14, 21, 8, 16, 24, 9, 18, 27
},
Sequence.of(1, 2, 3, 4, 5, 6, 7, 8, 9)
.flatMap(i -> Sequence.of(i, i * 2, i * 3))
.toTypedArray());
assertArrayEquals(
new String[] {"1", "2", "2", "3", "3", "4"},
Sequence.of(1, 2, 3)
.flatMap(i -> Sequence.of(String.valueOf(i), String.valueOf(i + 1)))
.toTypedArray());
}
// TODO: Start Here!
@Test
public void flatEmpty() {
assertEquals(
Sequence.emptySequence(),
Sequence.of(1, 2, 3, 4, 5, 6, 7, 8, 9).flatMap((a) -> Sequence.emptySequence()));
assertEquals(Sequence.emptySequence(), Sequence.of().flatMap((a) -> Sequence.emptySequence()));
// This tests that I didn't just look ahead 2 or 3 times. That the look-ahead is sufficient.
Mutable.Ref<Integer> count = Mutable.Ref.of(0);
assertArrayEquals(
new String[] {"a9", "b9"},
Sequence.of(1, 2, 3, 4, 5, 6, 7, 8, 9)
.flatMap(
(a) -> {
count.set(count.value() + 1);
return (count.value() > 8)
? Sequence.of("a" + a, "b" + a)
: Sequence.emptySequence();
})
.forEach(
(item) -> {
System.out.println("Item " + item);
return null;
})
.toTypedArray());
count.set(0);
assertArrayEquals(
new String[] {"c8", "d8", "c9", "d9"},
Sequence.of(1, 2, 3, 4, 5, 6, 7, 8, 9)
.flatMap(
(a) -> {
count.set(count.value() + 1);
return (count.value() > 7)
? Sequence.of("c" + a, "d" + a)
: Sequence.emptySequence();
})
// .forEach((item) -> {
// System.out.println("Item " + item);
// return null;
// })
.toTypedArray());
count.set(0);
assertArrayEquals(
new String[] {"e1", "f1", "e2", "f2"},
Sequence.of(1, 2, 3, 4, 5, 6, 7, 8, 9)
.flatMap(
(a) -> {
count.set(count.value() + 1);
return (count.value() < 3)
? Sequence.of("e" + a, "f" + a)
: Sequence.emptySequence();
})
// .forEach((item) -> {
// System.out.println("count: " + count.value() + " Item "
// + item);
// return null;
// })
.toTypedArray());
Mutable.Ref<Sequence<Integer>> shrinkSeq = Mutable.Ref.of(Sequence.of(1, 2, 3));
assertArrayEquals(
new Integer[] {2, 3, 3},
Sequence.of(1, 2, 3, 4, 5, 6, 7, 8, 9)
.flatMap(
(a) -> {
shrinkSeq.set(shrinkSeq.value().tail());
// System.out.print("seq val: " +
// shrinkSeq.value());
return shrinkSeq.value();
})
.toTypedArray());
// Now start by returning an emptySequence, then a seq of length 1, then length 2, etc.
// The first emptySequence should not end the processing.
Mutable.Ref<Sequence<Integer>> growSeq = Mutable.Ref.of(Sequence.emptySequence());
Mutable.Ref<Integer> incInt = Mutable.Ref.of(0);
assertArrayEquals(
new Integer[] {1, 1, 2},
Sequence.of(1, 2, 3)
.flatMap(
(a) -> {
if (incInt.value() > 0) {
growSeq.set(growSeq.value().concat(Sequence.of(incInt.value())));
}
incInt.set(incInt.value() + 1);
return growSeq.value();
})
.toTypedArray());
}
@Test(expected = IllegalArgumentException.class)
public void testNullFunction() {
Sequence.of(1, 2, 3).flatMap(null);
}
@RunWith(JUnit4.class)
public class SequenceFlatMappedTest {
public static final Function1<Integer, Sequence<Integer>> emptySeqFunc =
(i) -> Sequence.emptySequence();
public static final Function1<Object, Sequence<Object>> identSeqFunc = (i) -> Sequence.of(i);
@Test(expected = IllegalArgumentException.class)
public void testNullFunction() {
Sequence.of(1, 2, 3).flatMap(null);
}
@Test
public void singleFlatMap() {
assertEquals(
Sequence.emptySequence(), Sequence.of(1, 2, 3, 4, 5, 6, 7, 8, 9).flatMap(emptySeqFunc));
assertEquals(Sequence.emptySequence(), Sequence.emptySequence().flatMap(identSeqFunc));
assertArrayEquals(
new Integer[] {},
Sequence.of(1, 2, 3, 4, 5, 6, 7, 8, 9).flatMap(emptySeqFunc).toTypedArray());
assertArrayEquals(
new Integer[] {
1, 2, 3, 2, 4, 6, 3, 6, 9, 4, 8, 12, 5, 10, 15, 6, 12, 18, 7, 14, 21, 8, 16, 24, 9, 18, 27
},
Sequence.of(1, 2, 3, 4, 5, 6, 7, 8, 9)
.flatMap(i -> Sequence.of(i, i * 2, i * 3))
.toTypedArray());
assertArrayEquals(
new String[] {"1", "2", "2", "3", "3", "4"},
Sequence.of(1, 2, 3)
.flatMap(i -> Sequence.of(String.valueOf(i), String.valueOf(i + 1)))
.toTypedArray());
}
// TODO: Start Here!
@Test
public void flatEmpty() {
assertEquals(
Sequence.emptySequence(),
Sequence.of(1, 2, 3, 4, 5, 6, 7, 8, 9).flatMap((a) -> Sequence.emptySequence()));
assertEquals(Sequence.emptySequence(), Sequence.of().flatMap((a) -> Sequence.emptySequence()));
// This tests that I didn't just look ahead 2 or 3 times. That the look-ahead is sufficient.
Mutable.Ref<Integer> count = Mutable.Ref.of(0);
assertArrayEquals(
new String[] {"a9", "b9"},
Sequence.of(1, 2, 3, 4, 5, 6, 7, 8, 9)
.flatMap(
(a) -> {
count.set(count.value() + 1);
return (count.value() > 8)
? Sequence.of("a" + a, "b" + a)
: Sequence.emptySequence();
})
.forEach(
(item) -> {
System.out.println("Item " + item);
return null;
})
.toTypedArray());
count.set(0);
assertArrayEquals(
new String[] {"c8", "d8", "c9", "d9"},
Sequence.of(1, 2, 3, 4, 5, 6, 7, 8, 9)
.flatMap(
(a) -> {
count.set(count.value() + 1);
return (count.value() > 7)
? Sequence.of("c" + a, "d" + a)
: Sequence.emptySequence();
})
// .forEach((item) -> {
// System.out.println("Item " + item);
// return null;
// })
.toTypedArray());
count.set(0);
assertArrayEquals(
new String[] {"e1", "f1", "e2", "f2"},
Sequence.of(1, 2, 3, 4, 5, 6, 7, 8, 9)
.flatMap(
(a) -> {
count.set(count.value() + 1);
return (count.value() < 3)
? Sequence.of("e" + a, "f" + a)
: Sequence.emptySequence();
})
// .forEach((item) -> {
// System.out.println("count: " + count.value() + " Item "
// + item);
// return null;
// })
.toTypedArray());
Mutable.Ref<Sequence<Integer>> shrinkSeq = Mutable.Ref.of(Sequence.of(1, 2, 3));
assertArrayEquals(
new Integer[] {2, 3, 3},
Sequence.of(1, 2, 3, 4, 5, 6, 7, 8, 9)
.flatMap(
(a) -> {
shrinkSeq.set(shrinkSeq.value().tail());
// System.out.print("seq val: " +
// shrinkSeq.value());
return shrinkSeq.value();
})
.toTypedArray());
// Now start by returning an emptySequence, then a seq of length 1, then length 2, etc.
// The first emptySequence should not end the processing.
Mutable.Ref<Sequence<Integer>> growSeq = Mutable.Ref.of(Sequence.emptySequence());
Mutable.Ref<Integer> incInt = Mutable.Ref.of(0);
assertArrayEquals(
new Integer[] {1, 1, 2},
Sequence.of(1, 2, 3)
.flatMap(
(a) -> {
if (incInt.value() > 0) {
growSeq.set(growSeq.value().concat(Sequence.of(incInt.value())));
}
incInt.set(incInt.value() + 1);
return growSeq.value();
})
.toTypedArray());
}
@Test
public void flatMapChain() {
assertEquals(
Sequence.emptySequence(),
Sequence.of(1, 2, 3, 4, 5, 6, 7, 8, 9)
.flatMap(emptySeqFunc)
.flatMap(emptySeqFunc)
.flatMap(emptySeqFunc));
assertEquals(
Sequence.emptySequence(),
Sequence.emptySequence().flatMap(identSeqFunc).flatMap(identSeqFunc).flatMap(identSeqFunc));
assertArrayEquals(
new Integer[] {},
Sequence.of(1, 2, 3, 4, 5, 6, 7, 8, 9)
.flatMap(emptySeqFunc)
.flatMap(emptySeqFunc)
.flatMap(emptySeqFunc)
.toTypedArray());
assertArrayEquals(
new Integer[] {1, 2, 2, 3, 3, 4, 10, 11, 20, 21, 30, 31},
Sequence.of(1, 10)
.flatMap(i -> Sequence.of(i, i * 2, i * 3))
.flatMap(i -> Sequence.of(i, i + 1))
.toTypedArray());
}
}