https://github.com/johnlcox/motif

Scala-like pattern matching for Java 8
https://github.com/johnlcox/motif

lambda pattern-matching scala

Last synced: about 5 hours ago
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Scala-like pattern matching for Java 8

• Host: GitHub
• URL: https://github.com/johnlcox/motif
• Owner: johnlcox
• License: apache-2.0
• Created: 2015-05-21T02:09:07.000Z (over 9 years ago)
• Default Branch: master
• Last Pushed: 2018-02-07T01:57:06.000Z (over 6 years ago)
• Last Synced: 2024-04-16T11:19:57.989Z (7 months ago)
• Topics: lambda, pattern-matching, scala
• Language: Java
• Homepage: http://john.leacox.com/motif
• Size: 586 KB
• Stars: 147
• Watchers: 13
• Forks: 4
• Open Issues: 4
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
Motif

=====

A pattern matching library for Java 8. Motif provides scala-like pattern matching in Java 8.

## Examples

### FizzBuzz

```java

IntStream.range(0, 101).forEach(

    n -> System.out.println(

        match(Tuple2.of(n % 3, n % 5))

            .when(tuple2(eq(0), eq(0))).get(() -> "FizzBuzz")

            .when(tuple2(eq(0), any())).get(y -> "Fizz")

            .when(tuple2(any(), eq(0))).get(x -> "Buzz")

            .orElse(String.valueOf(n))

            .getMatch()

    )

);

```

### Optional

```java

Optional personOpt = getPerson();

match(personOpt)

    .when(some(any())).then(person -> doStuff(person))

    .when(none()).then(() -> System.out.println("Person not found"))

    .doMatch();

```

### Factorial

```java

public long factorial(long i) {

  return match(i)

      .when(eq(0)).get(() -> 1l)

      .when(any()).get(x -> x * factorial(x - 1))

      .getMatch();

}

```

### Nested Matching

```java

Optional> opt = Optional.of(Tuple2.of("first", "second"));

match(opt)

    .when(some(tuple2(eq("third"), any()))).then(b -> doStuff(b))

    .when(some(tuple2(any(), eq("second")))).then(a -> doStuff(a))

    .when(none()).then(() -> System.out.println("Tuple not found"))

    .doMatch();

```

### List Cons Matching

```java

List list = Arrays.asList("a", "b", "c", "d");

match(list)

    .when(nil()).then(() -> System.out.println("Empty List"))

    .when(headNil(eq("b"))).then(() -> System.out.println("Singleton List of 'b'"))

    .when(headNil(any())).then(head -> System.out.println("Singleton List of " + head))

    .when(headTail(any(), any())).then(

        (head, tail) -> System.out.println("head: " + head + " Remaining: " + tail))

    .doMatch();

```

## Download

Download the latest JAR via Maven:

```xml

  com.leacox.motif

  motif

  0.1

```

## License

    Copyright 2015 John Leacox

    Licensed under the Apache License, Version 2.0 (the "License");

    you may not use this file except in compliance with the License.

    You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software

    distributed under the License is distributed on an "AS IS" BASIS,

    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

    See the License for the specific language governing permissions and

    limitations under the License.