From 88e70febbe69067778242364d2398f897d725fe6 Mon Sep 17 00:00:00 2001 From: Alexander Bandukwala <7h3kk1d@gmail.com> Date: Fri, 31 Mar 2023 17:38:21 -0500 Subject: [PATCH 1/3] Switch chat badge to point to palatable discord --- README.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/README.md b/README.md index a1d7400b..11afcbe3 100644 --- a/README.md +++ b/README.md @@ -2,7 +2,7 @@ ====== [![Actions Status](https://github.com/palatable/lambda/workflows/Java%20CI/badge.svg)](https://github.com/palatable/lambda/actions) [![Lambda](https://img.shields.io/maven-central/v/com.jnape.palatable/lambda.svg)](http://search.maven.org/#search%7Cga%7C1%7Ccom.jnape.palatable.lambda) -[![Join the chat at https://gitter.im/palatable/lambda](https://badges.gitter.im/palatable/lambda.svg)](https://gitter.im/palatable/lambda?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge) +[![Join the chat on Discord](https://dcbadge.vercel.app/api/server/wR7k8RAKM5)](https://discord.gg/wR7k8RAKM5) [![Floobits Status](https://floobits.com/jnape/lambda.svg)](https://floobits.com/jnape/lambda/redirect) Functional patterns for Java From e4831180484a9b7eca8a7cbacff5dc1c3b0ed2ca Mon Sep 17 00:00:00 2001 From: Alexander Bandukwala <7h3kk1d@gmail.com> Date: Fri, 31 Mar 2023 17:49:49 -0500 Subject: [PATCH 2/3] Fix height of discord badge --- README.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/README.md b/README.md index 11afcbe3..7d84c629 100644 --- a/README.md +++ b/README.md @@ -2,7 +2,7 @@ ====== [![Actions Status](https://github.com/palatable/lambda/workflows/Java%20CI/badge.svg)](https://github.com/palatable/lambda/actions) [![Lambda](https://img.shields.io/maven-central/v/com.jnape.palatable/lambda.svg)](http://search.maven.org/#search%7Cga%7C1%7Ccom.jnape.palatable.lambda) -[![Join the chat on Discord](https://dcbadge.vercel.app/api/server/wR7k8RAKM5)](https://discord.gg/wR7k8RAKM5) +[Join the chat on Discord](https://discord.gg/wR7k8RAKM5) [![Floobits Status](https://floobits.com/jnape/lambda.svg)](https://floobits.com/jnape/lambda/redirect) Functional patterns for Java From c1d2193ebdbbac8b0b31bec9bdcbfbd5820858ff Mon Sep 17 00:00:00 2001 From: Alexander Bandukwala <7h3kk1d@gmail.com> Date: Thu, 20 Apr 2023 21:36:44 -0500 Subject: [PATCH 3/3] FoldRight fixes for Monoid/Semigroup - Semigroup::foldRight had parameters flipped - Monoid::foldRight was accumulating the accumulator from the left. This has been fixed but the identity is now being used as a starting accumulator. Otherwise, the evaluation order is unchanged. - Changed ExplainFold parameter name since accumulator can be in either position --- .../java/com/jnape/palatable/lambda/monoid/Monoid.java | 2 +- .../com/jnape/palatable/lambda/semigroup/Semigroup.java | 2 +- .../lambda/functions/builtin/fn3/FoldRightTest.java | 2 +- .../com/jnape/palatable/lambda/monoid/MonoidTest.java | 9 +++++++++ .../jnape/palatable/lambda/semigroup/SemigroupTest.java | 9 +++++---- src/test/java/testsupport/functions/ExplainFold.java | 2 +- 6 files changed, 18 insertions(+), 8 deletions(-) diff --git a/src/main/java/com/jnape/palatable/lambda/monoid/Monoid.java b/src/main/java/com/jnape/palatable/lambda/monoid/Monoid.java index 8ecf8377..59f4ce1c 100644 --- a/src/main/java/com/jnape/palatable/lambda/monoid/Monoid.java +++ b/src/main/java/com/jnape/palatable/lambda/monoid/Monoid.java @@ -82,7 +82,7 @@ default A foldLeft(A a, Iterable as) { */ @Override default Lazy foldRight(A a, Iterable as) { - return lazy(() -> flip().foldMap(id(), reverse(cons(a, as)))); + return lazy(() -> flip().foldMap(id(), cons(a, reverse(as)))); } /** diff --git a/src/main/java/com/jnape/palatable/lambda/semigroup/Semigroup.java b/src/main/java/com/jnape/palatable/lambda/semigroup/Semigroup.java index a061328c..d4cc1e6b 100644 --- a/src/main/java/com/jnape/palatable/lambda/semigroup/Semigroup.java +++ b/src/main/java/com/jnape/palatable/lambda/semigroup/Semigroup.java @@ -39,7 +39,7 @@ default A foldLeft(A a, Iterable as) { * @see FoldRight */ default Lazy foldRight(A a, Iterable as) { - return FoldRight.foldRight((y, lazyX) -> lazyX.fmap(x -> apply(x, y)), lazy(a), as); + return FoldRight.foldRight((y, lazyX) -> lazyX.fmap(x -> apply(y, x)), lazy(a), as); } /** diff --git a/src/test/java/com/jnape/palatable/lambda/functions/builtin/fn3/FoldRightTest.java b/src/test/java/com/jnape/palatable/lambda/functions/builtin/fn3/FoldRightTest.java index 912ee9b4..62f6d43c 100644 --- a/src/test/java/com/jnape/palatable/lambda/functions/builtin/fn3/FoldRightTest.java +++ b/src/test/java/com/jnape/palatable/lambda/functions/builtin/fn3/FoldRightTest.java @@ -29,7 +29,7 @@ public Fn1, Iterable> createTestSubject() { @Test public void foldRightAccumulatesRightToLeft() { - assertThat(foldRight((a, lazyB) -> lazyB.fmap(b -> explainFold().apply(a, b)), + assertThat(foldRight((a, lazyAcc) -> lazyAcc.fmap(acc -> explainFold().apply(a, acc)), lazy("5"), asList("1", "2", "3", "4")) .value(), diff --git a/src/test/java/com/jnape/palatable/lambda/monoid/MonoidTest.java b/src/test/java/com/jnape/palatable/lambda/monoid/MonoidTest.java index 87cfced3..135d8719 100644 --- a/src/test/java/com/jnape/palatable/lambda/monoid/MonoidTest.java +++ b/src/test/java/com/jnape/palatable/lambda/monoid/MonoidTest.java @@ -1,6 +1,7 @@ package com.jnape.palatable.lambda.monoid; import com.jnape.palatable.lambda.adt.Maybe; +import com.jnape.palatable.lambda.functor.builtin.Lazy; import org.junit.Test; import java.util.List; @@ -10,6 +11,7 @@ import static com.jnape.palatable.lambda.monoid.Monoid.monoid; import static java.util.Arrays.asList; import static org.junit.Assert.assertEquals; +import static testsupport.functions.ExplainFold.explainFold; public class MonoidTest { @@ -25,6 +27,13 @@ public void reduceRight() { assertEquals((Integer) 6, sum.reduceRight(asList(1, 2, 3))); } + @Test + public void foldRight() { + Lazy lazyString = monoid(explainFold()::apply, "0") + .foldRight("4", asList("1", "2", "3")); + assertEquals("(1 + (2 + (3 + (4 + 0))))", lazyString.value()); + } + @Test public void foldMap() { Monoid sum = monoid(Integer::sum, 0); diff --git a/src/test/java/com/jnape/palatable/lambda/semigroup/SemigroupTest.java b/src/test/java/com/jnape/palatable/lambda/semigroup/SemigroupTest.java index 3291b6b1..712c09e0 100644 --- a/src/test/java/com/jnape/palatable/lambda/semigroup/SemigroupTest.java +++ b/src/test/java/com/jnape/palatable/lambda/semigroup/SemigroupTest.java @@ -4,18 +4,19 @@ import static java.util.Arrays.asList; import static org.junit.Assert.assertEquals; +import static testsupport.functions.ExplainFold.explainFold; public class SemigroupTest { @Test public void foldLeft() { - Semigroup sum = (x, y) -> x + y; - assertEquals((Integer) 6, sum.foldLeft(0, asList(1, 2, 3))); + Semigroup foldFn = explainFold()::apply; + assertEquals("(((0 + 1) + 2) + 3)", foldFn.foldLeft("0", asList("1", "2", "3"))); } @Test public void foldRight() { - Semigroup sum = (x, y) -> x + y; - assertEquals((Integer) 6, sum.foldRight(0, asList(1, 2, 3)).value()); + Semigroup foldFn = explainFold()::apply; + assertEquals("(1 + (2 + (3 + 0)))", foldFn.foldRight("0", asList("1", "2", "3")).value()); } } \ No newline at end of file diff --git a/src/test/java/testsupport/functions/ExplainFold.java b/src/test/java/testsupport/functions/ExplainFold.java index d59a2378..ba5c2952 100644 --- a/src/test/java/testsupport/functions/ExplainFold.java +++ b/src/test/java/testsupport/functions/ExplainFold.java @@ -7,6 +7,6 @@ public class ExplainFold { public static Fn2 explainFold() { - return (acc, x) -> format("(%s + %s)", acc, x); + return (x, y) -> format("(%s + %s)", x, y); } }