From eba9e672cfbc577afa38f2a7e9b70d7069f89218 Mon Sep 17 00:00:00 2001
From: Alexander Bandukwala <7h3kk1d@gmail.com>
Date: Mon, 1 May 2023 16:41:46 -0500
Subject: [PATCH 1/5] Change language version to 17
---
pom.xml | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/pom.xml b/pom.xml
index bae03b1e..07e73502 100644
--- a/pom.xml
+++ b/pom.xml
@@ -91,8 +91,8 @@
<artifactId>maven-compiler-plugin</artifactId>
<version>${maven-compiler-plugin.version}</version>
<configuration>
- <source>1.8</source>
- <target>1.8</target>
+ <source>17</source>
+ <target>17</target>
<compilerArgs>
<compilerArg>-Xlint:all</compilerArg>
<compilerArg>-Werror</compilerArg>
From 59fa9129148ee0061800c5f2f810e9ba06255582 Mon Sep 17 00:00:00 2001
From: Alexander Bandukwala <7h3kk1d@gmail.com>
Date: Mon, 1 May 2023 16:47:06 -0500
Subject: [PATCH 2/5] Convert some classes to records
---
README.md | 23 +++++----------
.../lambda/functor/builtin/Exchange.java | 12 +++-----
.../lambda/functor/builtin/Market.java | 21 +++++++-------
.../testsupport/assertion/PrismAssert.java | 28 ++++++-------------
4 files changed, 30 insertions(+), 54 deletions(-)
diff --git a/README.md b/README.md
index 7d84c629..2e6aa98d 100644
--- a/README.md
+++ b/README.md
@@ -672,24 +672,15 @@ There are three functions that lambda provides that interface directly with lens
Lenses can be easily created. Consider the following `Person` class:
```Java
-public final class Person {
- private final int age;
+public record Person(int age) {
- public Person(int age) {
- this.age = age;
- }
-
- public int getAge() {
- return age;
- }
+ public Person setAge(int age) {
+ return new Person(age);
+ }
- public Person setAge(int age) {
- return new Person(age);
- }
-
- public Person setAge(LocalDate dob) {
- return setAge((int) YEARS.between(dob, LocalDate.now()));
- }
+ public Person setAge(LocalDate dob) {
+ return setAge((int) YEARS.between(dob, LocalDate.now()));
+ }
}
```
diff --git a/src/main/java/com/jnape/palatable/lambda/functor/builtin/Exchange.java b/src/main/java/com/jnape/palatable/lambda/functor/builtin/Exchange.java
index f0405036..bfd861e1 100644
--- a/src/main/java/com/jnape/palatable/lambda/functor/builtin/Exchange.java
+++ b/src/main/java/com/jnape/palatable/lambda/functor/builtin/Exchange.java
@@ -12,20 +12,15 @@
* @param <S> the larger viewing value of an {@link Iso}
* @param <T> the larger viewed value of an {@link Iso}
*/
-public final class Exchange<A, B, S, T> implements Profunctor<S, T, Exchange<A, B, ?, ?>> {
- private final Fn1<? super S, ? extends A> sa;
- private final Fn1<? super B, ? extends T> bt;
-
- public Exchange(Fn1<? super S, ? extends A> sa, Fn1<? super B, ? extends T> bt) {
- this.sa = sa;
- this.bt = bt;
- }
+public record Exchange<A, B, S, T>(Fn1<? super S, ? extends A> sa,
+ Fn1<? super B, ? extends T> bt) implements Profunctor<S, T, Exchange<A, B, ?, ?>> {
/**
* Extract the mapping <code>S -> A</code>.
*
* @return an <code>{@link Fn1}<S, A></code>
*/
+ @Override
public Fn1<? super S, ? extends A> sa() {
return sa;
}
@@ -35,6 +30,7 @@ public Exchange(Fn1<? super S, ? extends A> sa, Fn1<? super B, ? extends T> bt)
*
* @return an <code>{@link Fn1}<B, T></code>
*/
+ @Override
public Fn1<? super B, ? extends T> bt() {
return bt;
}
diff --git a/src/main/java/com/jnape/palatable/lambda/functor/builtin/Market.java b/src/main/java/com/jnape/palatable/lambda/functor/builtin/Market.java
index 3c8ce757..f5cb2937 100644
--- a/src/main/java/com/jnape/palatable/lambda/functor/builtin/Market.java
+++ b/src/main/java/com/jnape/palatable/lambda/functor/builtin/Market.java
@@ -28,13 +28,10 @@
* @param <S> the input that might fail to map to its output
* @param <T> the guaranteed output
*/
-public final class Market<A, B, S, T> implements
+public record Market<A, B, S, T>(Fn1<? super B, ? extends T> bt, Fn1<? super S, ? extends Either<T, A>> sta) implements
MonadRec<T, Market<A, B, S, ?>>,
Cocartesian<S, T, Market<A, B, ?, ?>> {
- private final Fn1<? super B, ? extends T> bt;
- private final Fn1<? super S, ? extends Either<T, A>> sta;
-
public Market(Fn1<? super B, ? extends T> bt, Fn1<? super S, ? extends Either<T, A>> sta) {
this.bt = fn1(bt);
this.sta = fn1(sta);
@@ -45,6 +42,7 @@ public Market(Fn1<? super B, ? extends T> bt, Fn1<? super S, ? extends Either<T,
*
* @return a <code>{@link Fn1}<B, T></code>
*/
+ @Override
public Fn1<? super B, ? extends T> bt() {
return bt;
}
@@ -54,6 +52,7 @@ public Market(Fn1<? super B, ? extends T> bt, Fn1<? super S, ? extends Either<T,
*
* @return a <code>{@link Fn1}<S, {@link Either}<T, A>></code>
*/
+ @Override
public Fn1<? super S, ? extends Either<T, A>> sta() {
return sta;
}
@@ -72,9 +71,9 @@ public <U> Market<A, B, S, U> pure(U u) {
@Override
public <U> Market<A, B, S, U> flatMap(Fn1<? super T, ? extends Monad<U, Market<A, B, S, ?>>> f) {
return new Market<>(b -> f.apply(bt().apply(b)).<Market<A, B, S, U>>coerce().bt().apply(b),
- s -> sta().apply(s).invert()
- .flatMap(t -> f.apply(t).<Market<A, B, S, U>>coerce().sta()
- .apply(s).invert()).invert());
+ s -> sta().apply(s).invert()
+ .flatMap(t -> f.apply(t).<Market<A, B, S, U>>coerce().sta()
+ .apply(s).invert()).invert());
}
/**
@@ -89,7 +88,7 @@ public <U> Market<A, B, S, U> trampolineM(
trampoline(t -> fn.apply(t).<Market<A, B, S, RecursiveResult<T, U>>>coerce()
.sta.apply(s)
.match(tOrU -> tOrU.match(RecursiveResult::recurse, u -> terminate(left(u))),
- a -> terminate(right(a)))),
+ a -> terminate(right(a)))),
Either::right)));
return new Market<>(bu, sua);
}
@@ -101,7 +100,7 @@ public <U> Market<A, B, S, U> trampolineM(
public <U> Market<A, B, S, U> zip(Applicative<Fn1<? super T, ? extends U>, Market<A, B, S, ?>> appFn) {
Market<A, B, S, Fn1<? super T, ? extends U>> marketF = appFn.coerce();
return new Market<>(b -> marketF.bt().apply(b).apply(bt().apply(b)),
- s -> sta().apply(s).invert().zip(marketF.sta().apply(s).invert()).invert());
+ s -> sta().apply(s).invert().zip(marketF.sta().apply(s).invert()).invert());
}
/**
@@ -118,8 +117,8 @@ public <U> Market<A, B, S, U> fmap(Fn1<? super T, ? extends U> fn) {
@Override
public <C> Market<A, B, Choice2<C, S>, Choice2<C, T>> cocartesian() {
return new Market<>(bt.fmap(Choice2::b),
- cs -> cs.fmap(sta).match(c -> left(a(c)),
- tOrA -> tOrA.match(t -> left(b(t)), Either::right)));
+ cs -> cs.fmap(sta).match(c -> left(a(c)),
+ tOrA -> tOrA.match(t -> left(b(t)), Either::right)));
}
/**
diff --git a/src/test/java/testsupport/assertion/PrismAssert.java b/src/test/java/testsupport/assertion/PrismAssert.java
index 443130fb..f10e30e8 100644
--- a/src/test/java/testsupport/assertion/PrismAssert.java
+++ b/src/test/java/testsupport/assertion/PrismAssert.java
@@ -59,29 +59,19 @@ private static <S, A, X> Maybe<String> falsify(String label, Fn2<S, A, X> l, Fn2
.apply(cases);
}
- private static final class PrismResult<S> {
- private final Maybe<S> maybeS;
-
- private PrismResult(Maybe<S> maybeS) {
- this.maybeS = maybeS;
- }
+ private record PrismResult<S>(Maybe<S> maybeS) {
@Override
- public boolean equals(Object other) {
- if (other instanceof PrismResult) {
- return maybeS.zip(((PrismResult<?>) other).maybeS.fmap(fn2(Objects::equals))).orElse(true);
+ public boolean equals(Object other) {
+ if (other instanceof PrismResult) {
+ return maybeS.zip(((PrismResult<?>) other).maybeS.fmap(fn2(Objects::equals))).orElse(true);
+ }
+ return false;
}
- return false;
- }
-
- @Override
- public int hashCode() {
- return Objects.hash(maybeS);
- }
@Override
- public String toString() {
- return maybeS.toString();
+ public String toString() {
+ return maybeS.toString();
+ }
}
- }
}
From aba344aab4e79251548a52bb6070b6bb4a4a3571 Mon Sep 17 00:00:00 2001
From: Alexander Bandukwala <7h3kk1d@gmail.com>
Date: Mon, 1 May 2023 16:50:15 -0500
Subject: [PATCH 3/5] Use pattern variables
---
.../java/com/jnape/palatable/lambda/adt/hlist/HList.java | 3 +--
src/main/java/com/jnape/palatable/lambda/adt/hmap/HMap.java | 3 +--
.../com/jnape/palatable/lambda/functor/builtin/Lazy.java | 3 +--
.../lambda/internal/iteration/DroppingIterable.java | 3 +--
.../lambda/internal/iteration/FilteringIterable.java | 3 +--
.../lambda/internal/iteration/MappingIterable.java | 3 +--
.../internal/iteration/PredicatedDroppingIterable.java | 3 +--
.../lambda/internal/iteration/PredicatedTakingIterable.java | 3 +--
.../lambda/internal/iteration/RateLimitingIterable.java | 3 +--
.../lambda/internal/iteration/ReversingIterable.java | 3 +--
.../palatable/lambda/internal/iteration/SnocIterable.java | 3 +--
.../palatable/lambda/internal/iteration/TakingIterable.java | 3 +--
src/main/java/com/jnape/palatable/lambda/io/IO.java | 6 ++----
13 files changed, 14 insertions(+), 28 deletions(-)
diff --git a/src/main/java/com/jnape/palatable/lambda/adt/hlist/HList.java b/src/main/java/com/jnape/palatable/lambda/adt/hlist/HList.java
index 705e43ba..0dc877fc 100644
--- a/src/main/java/com/jnape/palatable/lambda/adt/hlist/HList.java
+++ b/src/main/java/com/jnape/palatable/lambda/adt/hlist/HList.java
@@ -263,8 +263,7 @@ public Tail tail() {
@Override
public final boolean equals(Object other) {
- if (other instanceof HCons) {
- HCons<?, ?> that = (HCons<?, ?>) other;
+ if (other instanceof HCons<?, ?> that) {
return this.head.equals(that.head)
&& this.tail.equals(that.tail);
}
diff --git a/src/main/java/com/jnape/palatable/lambda/adt/hmap/HMap.java b/src/main/java/com/jnape/palatable/lambda/adt/hmap/HMap.java
index 62c922ec..db106f41 100644
--- a/src/main/java/com/jnape/palatable/lambda/adt/hmap/HMap.java
+++ b/src/main/java/com/jnape/palatable/lambda/adt/hmap/HMap.java
@@ -162,8 +162,7 @@ public Collection<Object> values() {
@Override
public boolean equals(Object other) {
- if (other instanceof HMap) {
- HMap that = (HMap) other;
+ if (other instanceof HMap that) {
return Objects.equals(this.table, that.table);
}
return false;
diff --git a/src/main/java/com/jnape/palatable/lambda/functor/builtin/Lazy.java b/src/main/java/com/jnape/palatable/lambda/functor/builtin/Lazy.java
index 83ec4771..6d941173 100644
--- a/src/main/java/com/jnape/palatable/lambda/functor/builtin/Lazy.java
+++ b/src/main/java/com/jnape/palatable/lambda/functor/builtin/Lazy.java
@@ -182,8 +182,7 @@ public A value() {
tuple((Lazy<Object>) this, new LinkedList<>());
@SuppressWarnings("unchecked")
A a = (A) trampoline(into((source, flatMaps) -> {
- if (source instanceof Compose<?>) {
- Compose<?> nested = (Compose<?>) source;
+ if (source instanceof Compose<?> nested) {
flatMaps.push(nested.flatMap);
return recurse(tuple(nested.source, flatMaps));
}
diff --git a/src/main/java/com/jnape/palatable/lambda/internal/iteration/DroppingIterable.java b/src/main/java/com/jnape/palatable/lambda/internal/iteration/DroppingIterable.java
index 1d9534b1..88a1719e 100644
--- a/src/main/java/com/jnape/palatable/lambda/internal/iteration/DroppingIterable.java
+++ b/src/main/java/com/jnape/palatable/lambda/internal/iteration/DroppingIterable.java
@@ -7,8 +7,7 @@ public final class DroppingIterable<A> implements Iterable<A> {
private final Iterable<A> as;
public DroppingIterable(int n, Iterable<A> as) {
- while (as instanceof DroppingIterable) {
- DroppingIterable<A> nested = (DroppingIterable<A>) as;
+ while (as instanceof DroppingIterable<A> nested) {
as = nested.as;
n += nested.n;
}
diff --git a/src/main/java/com/jnape/palatable/lambda/internal/iteration/FilteringIterable.java b/src/main/java/com/jnape/palatable/lambda/internal/iteration/FilteringIterable.java
index 7accde2f..75c4879a 100644
--- a/src/main/java/com/jnape/palatable/lambda/internal/iteration/FilteringIterable.java
+++ b/src/main/java/com/jnape/palatable/lambda/internal/iteration/FilteringIterable.java
@@ -15,8 +15,7 @@ public final class FilteringIterable<A> implements Iterable<A> {
public FilteringIterable(Fn1<? super A, ? extends Boolean> predicate, Iterable<A> as) {
List<Fn1<? super A, ? extends Boolean>> predicates = new ArrayList<>(singletonList(predicate));
- while (as instanceof FilteringIterable) {
- FilteringIterable<A> nested = (FilteringIterable<A>) as;
+ while (as instanceof FilteringIterable<A> nested) {
predicates.addAll(0, nested.predicates);
as = nested.as;
}
diff --git a/src/main/java/com/jnape/palatable/lambda/internal/iteration/MappingIterable.java b/src/main/java/com/jnape/palatable/lambda/internal/iteration/MappingIterable.java
index 3d2f1ba6..548fc795 100644
--- a/src/main/java/com/jnape/palatable/lambda/internal/iteration/MappingIterable.java
+++ b/src/main/java/com/jnape/palatable/lambda/internal/iteration/MappingIterable.java
@@ -16,8 +16,7 @@ public final class MappingIterable<A, B> implements Iterable<B> {
@SuppressWarnings("unchecked")
public MappingIterable(Fn1<? super A, ? extends B> fn, Iterable<A> as) {
List<Fn1<?, ?>> mappers = new ArrayList<>(singletonList(fn));
- while (as instanceof MappingIterable<?, ?>) {
- MappingIterable<?, ?> nested = (MappingIterable<?, ?>) as;
+ while (as instanceof MappingIterable<?, ?> nested) {
as = (Iterable<A>) nested.as;
mappers.addAll(0, nested.mappers);
}
diff --git a/src/main/java/com/jnape/palatable/lambda/internal/iteration/PredicatedDroppingIterable.java b/src/main/java/com/jnape/palatable/lambda/internal/iteration/PredicatedDroppingIterable.java
index ea7b68bc..e96310b1 100644
--- a/src/main/java/com/jnape/palatable/lambda/internal/iteration/PredicatedDroppingIterable.java
+++ b/src/main/java/com/jnape/palatable/lambda/internal/iteration/PredicatedDroppingIterable.java
@@ -11,8 +11,7 @@ public final class PredicatedDroppingIterable<A> implements Iterable<A> {
public PredicatedDroppingIterable(Fn1<? super A, ? extends Boolean> predicate, Iterable<A> as) {
ImmutableQueue<Fn1<? super A, ? extends Boolean>> predicates = ImmutableQueue.singleton(predicate);
- while (as instanceof PredicatedDroppingIterable) {
- PredicatedDroppingIterable<A> nested = (PredicatedDroppingIterable<A>) as;
+ while (as instanceof PredicatedDroppingIterable<A> nested) {
as = nested.as;
predicates = nested.predicates.concat(predicates);
}
diff --git a/src/main/java/com/jnape/palatable/lambda/internal/iteration/PredicatedTakingIterable.java b/src/main/java/com/jnape/palatable/lambda/internal/iteration/PredicatedTakingIterable.java
index de9c7682..92d5a5a5 100644
--- a/src/main/java/com/jnape/palatable/lambda/internal/iteration/PredicatedTakingIterable.java
+++ b/src/main/java/com/jnape/palatable/lambda/internal/iteration/PredicatedTakingIterable.java
@@ -15,8 +15,7 @@ public final class PredicatedTakingIterable<A> implements Iterable<A> {
public PredicatedTakingIterable(Fn1<? super A, ? extends Boolean> predicate, Iterable<A> as) {
List<Fn1<? super A, ? extends Boolean>> predicates = new ArrayList<>(singletonList(predicate));
- while (as instanceof PredicatedTakingIterable) {
- PredicatedTakingIterable<A> nested = (PredicatedTakingIterable<A>) as;
+ while (as instanceof PredicatedTakingIterable<A> nested) {
predicates.addAll(0, nested.predicates);
as = nested.as;
}
diff --git a/src/main/java/com/jnape/palatable/lambda/internal/iteration/RateLimitingIterable.java b/src/main/java/com/jnape/palatable/lambda/internal/iteration/RateLimitingIterable.java
index 3a7c856d..fe5240dd 100644
--- a/src/main/java/com/jnape/palatable/lambda/internal/iteration/RateLimitingIterable.java
+++ b/src/main/java/com/jnape/palatable/lambda/internal/iteration/RateLimitingIterable.java
@@ -15,8 +15,7 @@ public final class RateLimitingIterable<A> implements Iterable<A> {
public RateLimitingIterable(Iterable<A> as, Set<Tuple3<Long, Duration, Fn0<Instant>>> rateLimits) {
Set<Tuple3<Long, Duration, Fn0<Instant>>> combinedRateLimits = new HashSet<>(rateLimits);
- if (as instanceof RateLimitingIterable) {
- RateLimitingIterable<A> inner = (RateLimitingIterable<A>) as;
+ if (as instanceof RateLimitingIterable<A> inner) {
combinedRateLimits.addAll(inner.rateLimits);
as = inner.as;
}
diff --git a/src/main/java/com/jnape/palatable/lambda/internal/iteration/ReversingIterable.java b/src/main/java/com/jnape/palatable/lambda/internal/iteration/ReversingIterable.java
index 29aff81d..46afde55 100644
--- a/src/main/java/com/jnape/palatable/lambda/internal/iteration/ReversingIterable.java
+++ b/src/main/java/com/jnape/palatable/lambda/internal/iteration/ReversingIterable.java
@@ -8,8 +8,7 @@ public final class ReversingIterable<A> implements Iterable<A> {
public ReversingIterable(Iterable<A> as) {
boolean reverse = true;
- while (as instanceof ReversingIterable) {
- ReversingIterable<A> nested = (ReversingIterable<A>) as;
+ while (as instanceof ReversingIterable<A> nested) {
as = nested.as;
reverse = !nested.reverse;
}
diff --git a/src/main/java/com/jnape/palatable/lambda/internal/iteration/SnocIterable.java b/src/main/java/com/jnape/palatable/lambda/internal/iteration/SnocIterable.java
index 9a011820..b43c994b 100644
--- a/src/main/java/com/jnape/palatable/lambda/internal/iteration/SnocIterable.java
+++ b/src/main/java/com/jnape/palatable/lambda/internal/iteration/SnocIterable.java
@@ -12,8 +12,7 @@ public final class SnocIterable<A> implements Iterable<A> {
public SnocIterable(A a, Iterable<A> as) {
Iterable<A> snocs = cons(a, Collections::emptyIterator);
- while (as instanceof SnocIterable) {
- SnocIterable<A> nested = ((SnocIterable<A>) as);
+ while (as instanceof SnocIterable<A> nested) {
as = nested.as;
snocs = concat(nested.snocs, snocs);
}
diff --git a/src/main/java/com/jnape/palatable/lambda/internal/iteration/TakingIterable.java b/src/main/java/com/jnape/palatable/lambda/internal/iteration/TakingIterable.java
index f228b596..3d153dd5 100644
--- a/src/main/java/com/jnape/palatable/lambda/internal/iteration/TakingIterable.java
+++ b/src/main/java/com/jnape/palatable/lambda/internal/iteration/TakingIterable.java
@@ -9,8 +9,7 @@ public final class TakingIterable<A> implements Iterable<A> {
private final Iterable<A> as;
public TakingIterable(int n, Iterable<A> as) {
- while (as instanceof TakingIterable) {
- TakingIterable<A> nested = (TakingIterable<A>) as;
+ while (as instanceof TakingIterable<A> nested) {
n = min(n, nested.n);
as = nested.as;
}
diff --git a/src/main/java/com/jnape/palatable/lambda/io/IO.java b/src/main/java/com/jnape/palatable/lambda/io/IO.java
index 6af4dc1b..65214986 100644
--- a/src/main/java/com/jnape/palatable/lambda/io/IO.java
+++ b/src/main/java/com/jnape/palatable/lambda/io/IO.java
@@ -430,8 +430,7 @@ private Compose(IO<?> source, Choice2<IO<?>, Fn1<Object, IO<?>>> composition) {
public A unsafePerformIO() {
Lazy<Object> lazyA = LazyRec.<IO<?>, Object>lazyRec(
(f, io) -> {
- if (io instanceof IO.Compose<?>) {
- Compose<?> compose = (Compose<?>) io;
+ if (io instanceof Compose<?> compose) {
Lazy<Object> head = f.apply(compose.source);
return compose.composition
.match(zip -> head.flatMap(x -> f.apply(zip)
@@ -450,8 +449,7 @@ public A unsafePerformIO() {
public CompletableFuture<A> unsafePerformAsyncIO(Executor executor) {
Lazy<CompletableFuture<Object>> lazyFuture = LazyRec.<IO<?>, CompletableFuture<Object>>lazyRec(
(f, io) -> {
- if (io instanceof IO.Compose<?>) {
- Compose<?> compose = (Compose<?>) io;
+ if (io instanceof Compose<?> compose) {
Lazy<CompletableFuture<Object>> head = f.apply(compose.source);
return compose.composition
.match(zip -> head.flatMap(futureX -> f.apply(zip)
From 956b1185fbfe3f3d46a72d516f9f7340294b84bd Mon Sep 17 00:00:00 2001
From: Alexander Bandukwala <7h3kk1d@gmail.com>
Date: Mon, 1 May 2023 16:50:57 -0500
Subject: [PATCH 4/5] Use collection factory calls
---
.../palatable/lambda/optics/lenses/MapLensTest.java | 12 ++----------
1 file changed, 2 insertions(+), 10 deletions(-)
diff --git a/src/test/java/com/jnape/palatable/lambda/optics/lenses/MapLensTest.java b/src/test/java/com/jnape/palatable/lambda/optics/lenses/MapLensTest.java
index 5a97e5b4..39c15b3e 100644
--- a/src/test/java/com/jnape/palatable/lambda/optics/lenses/MapLensTest.java
+++ b/src/test/java/com/jnape/palatable/lambda/optics/lenses/MapLensTest.java
@@ -176,17 +176,9 @@ public void mappingValuesWithIsoRetainsMapStructureWithMappedValues() {
assertLensLawfulness(mappingValues(iso(Integer::parseInt, Object::toString)),
asList(emptyMap(),
singletonMap("foo", "1"),
- unmodifiableMap(new HashMap<String, String>() {{
- put("foo", "1");
- put("bar", "2");
- put("baz", "3");
- }})),
+ Map.of("foo", "1", "bar", "2", "baz", "3")),
asList(emptyMap(),
singletonMap("foo", 1),
- unmodifiableMap(new HashMap<String, Integer>() {{
- put("foo", 1);
- put("bar", 2);
- put("baz", 3);
- }})));
+ Map.of("foo", 1, "bar", 2, "baz", 3)));
}
}
\ No newline at end of file
From 83c8aae92868b2013ab6f7f12d1343ce22c2ec10 Mon Sep 17 00:00:00 2001
From: Alexander Bandukwala <7h3kk1d@gmail.com>
Date: Mon, 1 May 2023 17:12:30 -0500
Subject: [PATCH 5/5] Try making maybe a sealed interface
---
.../com/jnape/palatable/lambda/adt/Maybe.java | 116 +++++++-----------
1 file changed, 41 insertions(+), 75 deletions(-)
diff --git a/src/main/java/com/jnape/palatable/lambda/adt/Maybe.java b/src/main/java/com/jnape/palatable/lambda/adt/Maybe.java
index dc559598..acb46311 100644
--- a/src/main/java/com/jnape/palatable/lambda/adt/Maybe.java
+++ b/src/main/java/com/jnape/palatable/lambda/adt/Maybe.java
@@ -18,7 +18,6 @@
import com.jnape.palatable.lambda.monad.MonadRec;
import com.jnape.palatable.lambda.traversable.Traversable;
-import java.util.Objects;
import java.util.Optional;
import static com.jnape.palatable.lambda.adt.Either.left;
@@ -38,14 +37,12 @@
* @param <A> the optional parameter type
* @see Optional
*/
-public abstract class Maybe<A> implements
+public sealed interface Maybe<A> extends
CoProduct2<Unit, A, Maybe<A>>,
MonadError<Unit, A, Maybe<?>>,
MonadRec<A, Maybe<?>>,
- Traversable<A, Maybe<?>> {
+ Traversable<A, Maybe<?>> permits Just, Nothing {
- private Maybe() {
- }
/**
* If the value is present, return it; otherwise, return the value supplied by <code>otherSupplier</code>.
@@ -53,7 +50,7 @@ private Maybe() {
* @param otherFn0 the supplier for the other value
* @return this value, or the supplied other value
*/
- public final A orElseGet(Fn0<A> otherFn0) {
+ default A orElseGet(Fn0<A> otherFn0) {
return match(__ -> otherFn0.apply(), id());
}
@@ -63,7 +60,7 @@ public final A orElseGet(Fn0<A> otherFn0) {
* @param other the other value
* @return this value, or the other value
*/
- public final A orElse(A other) {
+ default A orElse(A other) {
return orElseGet(() -> other);
}
@@ -76,7 +73,7 @@ public final A orElse(A other) {
* @return the value, if present
* @throws E the throwable, if the value is absent
*/
- public final <E extends Throwable> A orElseThrow(Fn0<? extends E> throwableSupplier) throws E {
+ default <E extends Throwable> A orElseThrow(Fn0<? extends E> throwableSupplier) throws E {
return orElseGet(fn0(() -> {
throw throwableSupplier.apply();
}));
@@ -89,7 +86,7 @@ public final <E extends Throwable> A orElseThrow(Fn0<? extends E> throwableSuppl
* @param predicate the predicate to apply to the possibly absent value
* @return maybe the present value that satisfied the predicate
*/
- public final Maybe<A> filter(Fn1<? super A, ? extends Boolean> predicate) {
+ default Maybe<A> filter(Fn1<? super A, ? extends Boolean> predicate) {
return flatMap(a -> predicate.apply(a) ? just(a) : nothing());
}
@@ -97,7 +94,7 @@ public final Maybe<A> filter(Fn1<? super A, ? extends Boolean> predicate) {
* {@inheritDoc}
*/
@Override
- public Maybe<A> throwError(Unit unit) {
+ default Maybe<A> throwError(Unit unit) {
return nothing();
}
@@ -105,7 +102,7 @@ public Maybe<A> throwError(Unit unit) {
* {@inheritDoc}
*/
@Override
- public Maybe<A> catchError(Fn1<? super Unit, ? extends Monad<A, Maybe<?>>> recoveryFn) {
+ default Maybe<A> catchError(Fn1<? super Unit, ? extends Monad<A, Maybe<?>>> recoveryFn) {
return match(recoveryFn, Maybe::just).coerce();
}
@@ -117,7 +114,7 @@ public Maybe<A> catchError(Fn1<? super Unit, ? extends Monad<A, Maybe<?>>> recov
* @param lFn0 the supplier for the left value
* @return this value wrapped in an Either.right, or an Either.left around the result of lSupplier
*/
- public final <L> Either<L, A> toEither(Fn0<L> lFn0) {
+ default <L> Either<L, A> toEither(Fn0<L> lFn0) {
return fmap(Either::<L, A>right).orElseGet(() -> left(lFn0.apply()));
}
@@ -126,7 +123,7 @@ public final <L> Either<L, A> toEither(Fn0<L> lFn0) {
*
* @return the Optional
*/
- public final Optional<A> toOptional() {
+ default Optional<A> toOptional() {
return fmap(Optional::of).orElseGet(Optional::empty);
}
@@ -138,7 +135,7 @@ public final Optional<A> toOptional() {
* @return Just b
*/
@Override
- public final <B> Maybe<B> pure(B b) {
+ default <B> Maybe<B> pure(B b) {
return just(b);
}
@@ -149,7 +146,7 @@ public final <B> Maybe<B> pure(B b) {
* {@link Maybe#nothing}.
*/
@Override
- public final <B> Maybe<B> fmap(Fn1<? super A, ? extends B> fn) {
+ default <B> Maybe<B> fmap(Fn1<? super A, ? extends B> fn) {
return MonadError.super.<B>fmap(fn).coerce();
}
@@ -157,7 +154,7 @@ public final <B> Maybe<B> fmap(Fn1<? super A, ? extends B> fn) {
* {@inheritDoc}
*/
@Override
- public final <B> Maybe<B> zip(Applicative<Fn1<? super A, ? extends B>, Maybe<?>> appFn) {
+ default <B> Maybe<B> zip(Applicative<Fn1<? super A, ? extends B>, Maybe<?>> appFn) {
return MonadError.super.zip(appFn).coerce();
}
@@ -169,7 +166,7 @@ public final <B> Maybe<B> zip(Applicative<Fn1<? super A, ? extends B>, Maybe<?>>
* @return the zipped {@link Maybe}
*/
@Override
- public <B> Lazy<Maybe<B>> lazyZip(Lazy<? extends Applicative<Fn1<? super A, ? extends B>, Maybe<?>>> lazyAppFn) {
+ default <B> Lazy<Maybe<B>> lazyZip(Lazy<? extends Applicative<Fn1<? super A, ? extends B>, Maybe<?>>> lazyAppFn) {
return match(constantly(lazy(nothing())),
a -> lazyAppFn.fmap(maybeF -> maybeF.<B>fmap(f -> f.apply(a)).coerce()));
}
@@ -178,7 +175,7 @@ public <B> Lazy<Maybe<B>> lazyZip(Lazy<? extends Applicative<Fn1<? super A, ? ex
* {@inheritDoc}
*/
@Override
- public final <B> Maybe<B> discardL(Applicative<B, Maybe<?>> appB) {
+ default <B> Maybe<B> discardL(Applicative<B, Maybe<?>> appB) {
return MonadError.super.discardL(appB).coerce();
}
@@ -186,7 +183,7 @@ public final <B> Maybe<B> discardL(Applicative<B, Maybe<?>> appB) {
* {@inheritDoc}
*/
@Override
- public final <B> Maybe<A> discardR(Applicative<B, Maybe<?>> appB) {
+ default <B> Maybe<A> discardR(Applicative<B, Maybe<?>> appB) {
return MonadError.super.discardR(appB).coerce();
}
@@ -195,7 +192,7 @@ public final <B> Maybe<A> discardR(Applicative<B, Maybe<?>> appB) {
*/
@SuppressWarnings("RedundantTypeArguments")
@Override
- public final <B> Maybe<B> flatMap(Fn1<? super A, ? extends Monad<B, Maybe<?>>> f) {
+ default <B> Maybe<B> flatMap(Fn1<? super A, ? extends Monad<B, Maybe<?>>> f) {
return match(constantly(nothing()), f.fmap(Monad<B, Maybe<?>>::coerce));
}
@@ -203,7 +200,7 @@ public final <B> Maybe<B> flatMap(Fn1<? super A, ? extends Monad<B, Maybe<?>>> f
* {@inheritDoc}
*/
@Override
- public <B> Maybe<B> trampolineM(Fn1<? super A, ? extends MonadRec<RecursiveResult<A, B>, Maybe<?>>> fn) {
+ default <B> Maybe<B> trampolineM(Fn1<? super A, ? extends MonadRec<RecursiveResult<A, B>, Maybe<?>>> fn) {
return match(constantly(nothing()), trampoline(a -> fn.apply(a).<Maybe<RecursiveResult<A, B>>>coerce()
.match(constantly(terminate(nothing())),
aOrB -> aOrB.fmap(Maybe::just))));
@@ -213,7 +210,7 @@ public <B> Maybe<B> trampolineM(Fn1<? super A, ? extends MonadRec<RecursiveResul
* {@inheritDoc}
*/
@Override
- public <B> Choice3<Unit, A, B> diverge() {
+ default <B> Choice3<Unit, A, B> diverge() {
return match(Choice3::a, Choice3::b);
}
@@ -221,7 +218,7 @@ public <B> Choice3<Unit, A, B> diverge() {
* {@inheritDoc}
*/
@Override
- public Tuple2<Maybe<Unit>, Maybe<A>> project() {
+ default Tuple2<Maybe<Unit>, Maybe<A>> project() {
return CoProduct2.super.project().into(HList::tuple);
}
@@ -229,7 +226,7 @@ public Tuple2<Maybe<Unit>, Maybe<A>> project() {
* {@inheritDoc}
*/
@Override
- public Choice2<A, Unit> invert() {
+ default Choice2<A, Unit> invert() {
return match(Choice2::b, Choice2::a);
}
@@ -241,13 +238,13 @@ public Choice2<A, Unit> invert() {
* @deprecated in favor of {@link Maybe#match(Fn1, Fn1) matching} into an {@link IO} and explicitly running it
*/
@Deprecated
- public final Maybe<A> peek(Fn1<? super A, ? extends IO<?>> effect) {
+ default Maybe<A> peek(Fn1<? super A, ? extends IO<?>> effect) {
return match(constantly(io(this)), a -> effect.apply(a).fmap(constantly(this))).unsafePerformIO();
}
@Override
@SuppressWarnings("unchecked")
- public final <B, App extends Applicative<?, App>, TravB extends Traversable<B, Maybe<?>>,
+ default <B, App extends Applicative<?, App>, TravB extends Traversable<B, Maybe<?>>,
AppTrav extends Applicative<TravB, App>> AppTrav traverse(Fn1<? super A, ? extends Applicative<B, App>> fn,
Fn1<? super TravB, ? extends AppTrav> pure) {
return match(__ -> pure.apply((TravB) Maybe.<B>nothing()), a -> (AppTrav) fn.apply(a).fmap(Maybe::just));
@@ -261,7 +258,7 @@ AppTrav extends Applicative<TravB, App>> AppTrav traverse(Fn1<? super A, ? exten
* @param <A> the potential right value
* @return "Just" the right value, or nothing
*/
- public static <A> Maybe<A> fromEither(Either<?, A> either) {
+ static <A> Maybe<A> fromEither(Either<?, A> either) {
return either.toMaybe();
}
@@ -272,7 +269,7 @@ public static <A> Maybe<A> fromEither(Either<?, A> either) {
* @param <A> the optional parameter type
* @return the equivalent Maybe instance
*/
- public static <A> Maybe<A> fromOptional(Optional<? extends A> optional) {
+ static <A> Maybe<A> fromOptional(Optional<? extends A> optional) {
return optional.map(Maybe::<A>just).orElse(Maybe.nothing());
}
@@ -284,7 +281,7 @@ public static <A> Maybe<A> fromOptional(Optional<? extends A> optional) {
* @param <A> the value parameter type
* @return "Just" the value, or nothing
*/
- public static <A> Maybe<A> maybe(A a) {
+ static <A> Maybe<A> maybe(A a) {
return a == null ? nothing() : just(a);
}
@@ -297,7 +294,7 @@ public static <A> Maybe<A> maybe(A a) {
* @return "Just" the value
* @throws NullPointerException if a is null
*/
- public static <A> Maybe<A> just(A a) {
+ static <A> Maybe<A> just(A a) {
if (a == null)
throw new NullPointerException();
return new Just<>(a);
@@ -310,7 +307,7 @@ public static <A> Maybe<A> just(A a) {
* @return nothing
*/
@SuppressWarnings("unchecked")
- public static <A> Maybe<A> nothing() {
+ static <A> Maybe<A> nothing() {
return (Maybe<A>) Nothing.INSTANCE;
}
@@ -319,53 +316,22 @@ public static <A> Maybe<A> nothing() {
*
* @return the {@link Pure} instance
*/
- public static Pure<Maybe<?>> pureMaybe() {
+ static Pure<Maybe<?>> pureMaybe() {
return Maybe::just;
}
+}
+record Nothing<A>() implements Maybe<A> {
+ static final Nothing<?> INSTANCE = new Nothing<>();
- private static final class Nothing<A> extends Maybe<A> {
- private static final Nothing<?> INSTANCE = new Nothing<>();
-
- private Nothing() {
- }
-
- @Override
- public <R> R match(Fn1<? super Unit, ? extends R> aFn, Fn1<? super A, ? extends R> bFn) {
- return aFn.apply(UNIT);
- }
-
- @Override
- public String toString() {
- return "Nothing";
- }
+ @Override
+ public <R> R match(Fn1<? super Unit, ? extends R> aFn, Fn1<? super A, ? extends R> bFn) {
+ return aFn.apply(UNIT);
}
+}
- private static final class Just<A> extends Maybe<A> {
-
- private final A a;
-
- private Just(A a) {
- this.a = a;
- }
-
- @Override
- public <R> R match(Fn1<? super Unit, ? extends R> aFn, Fn1<? super A, ? extends R> bFn) {
- return bFn.apply(a);
- }
-
- @Override
- public boolean equals(Object other) {
- return other instanceof Just && Objects.equals(this.a, ((Just) other).a);
- }
-
- @Override
- public int hashCode() {
- return Objects.hash(a);
- }
-
- @Override
- public String toString() {
- return "Just " + a;
- }
+record Just<A>(A a) implements Maybe<A> {
+ @Override
+ public <R> R match(Fn1<? super Unit, ? extends R> aFn, Fn1<? super A, ? extends R> bFn) {
+ return bFn.apply(a);
}
-}
+}
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