<dependency>
<groupId>io.vavr</groupId>
<artifactId>vavr</artifactId>
<version>0.11.0</version>
</dependency>implementation 'io.vavr:vavr:0.11.0'Features
Why Vavr?
Write expressive, type-safe functional code in Java.
Collections
Immutable Collections
No more stream().collect() pipelines. Operate on values directly.
List<String> names = persons
.filter(p -> p.age > 12)
.map(Person::getName);Control Flow
Pattern Matching
Decompose values structurally.
Number num = Match(opt).of(
Case($Some($()), v -> 1.0d),
Case($None(), 0)
);Error Handling
Try Monad
Functional success and failure.
R result = Try(() -> mightFail())
.recover(x -> ...)
.getOrElse(defaultValue);Expressions
For Comprehension
Lazy evaluated collection expressions that yield values.
Iterator<String> result =
For(persons.filter(Person::hasAddress), p ->
For(p.addresses).yield(a ->
p.name + "," + a.street
)
);Types
Option
Serializable alternative to Optional.
class Person implements Serializable {
final Option<String> title;
final String name;
}Interop
Java Compatible
Seamlessly convert back and forth.
java.util.List<Integer> result =
iterator.map(String::length)
.asJava();Ecosystem
Modules
Additional modules complementing Vavr's core.