aboutsummaryrefslogtreecommitdiff
path: root/Mammoth/Couscous/java/util/Optional.cs
diff options
context:
space:
mode:
authorMichael Williamson <mike@zwobble.org>2016-04-30 17:20:53 +0100
committerMichael Williamson <mike@zwobble.org>2016-04-30 17:20:53 +0100
commitec5037c01868fecaec2eba89b975f3e53aded89a (patch)
treee0d5a092419bace577a90eb29699f5be57f36078 /Mammoth/Couscous/java/util/Optional.cs
parent17d1a1f710edd8dfb92e75bcd273e04cee7c8146 (diff)
Export from java-mammoth 5f538798b147f0e76
Diffstat (limited to 'Mammoth/Couscous/java/util/Optional.cs')
-rw-r--r--Mammoth/Couscous/java/util/Optional.cs103
1 files changed, 103 insertions, 0 deletions
diff --git a/Mammoth/Couscous/java/util/Optional.cs b/Mammoth/Couscous/java/util/Optional.cs
new file mode 100644
index 0000000..f295688
--- /dev/null
+++ b/Mammoth/Couscous/java/util/Optional.cs
@@ -0,0 +1,103 @@
+using System;
+using Mammoth.Couscous.java.util.function;
+
+namespace Mammoth.Couscous.java.util
+{
+ internal interface Optional<T>
+ {
+ bool isPresent();
+ Optional<U> map<U>(Function<T, U> function);
+ Optional<U> flatMap<U>(Function<T, Optional<U>> function);
+ T orElse(T value);
+ T orElseGet(Supplier<T> supplier);
+ T orElseThrow<TException>(Supplier<TException> exceptionSupplier) where TException : Exception;
+ T get();
+ void ifPresent(Consumer<T> consumer);
+ }
+
+ internal class None<T> : Optional<T> {
+ public bool isPresent() {
+ return false;
+ }
+
+ public Optional<U> map<U>(Function<T, U> function) {
+ return new None<U>();
+ }
+
+ public Optional<U> flatMap<U>(Function<T, Optional<U>> function) {
+ return new None<U>();
+ }
+
+ public T orElse(T value) {
+ return value;
+ }
+
+ public T orElseGet(Supplier<T> supplier) {
+ return supplier.get();
+ }
+
+ public T orElseThrow<TException>(Supplier<TException> exceptionSupplier) where TException : Exception {
+ throw exceptionSupplier.get();
+ }
+
+ public T get() {
+ throw new NoSuchElementException();
+ }
+
+ public void ifPresent(Consumer<T> consumer) {
+ }
+ }
+
+ internal class Some<T> : Optional<T> {
+ private readonly T _value;
+
+ internal Some(T value) {
+ _value = value;
+ }
+
+ public bool isPresent() {
+ return true;
+ }
+
+ public Optional<U> map<U>(Function<T, U> function) {
+ return new Some<U>(function.apply(_value));
+ }
+
+ public Optional<U> flatMap<U>(Function<T, Optional<U>> function) {
+ return function.apply(_value);
+ }
+
+ public T orElse(T value) {
+ return _value;
+ }
+
+ public T orElseGet(Supplier<T> supplier) {
+ return _value;
+ }
+
+ public T orElseThrow<TException>(Supplier<TException> exceptionSupplier) where TException : Exception {
+ return _value;
+ }
+
+ public T get() {
+ return _value;
+ }
+
+ public void ifPresent(Consumer<T> consumer) {
+ consumer.accept(_value);
+ }
+ }
+
+ internal static class Optional
+ {
+ internal static Optional<T> empty<T>()
+ {
+ return new None<T>();
+ }
+
+ internal static Optional<T> of<T>(T value)
+ {
+ return new Some<T> (value);
+ }
+ }
+}