getSomes, getLefts, getRights

SandroMaglione · Mar 24, 2024 · 60290a9 · 60290a9
1 parent de6395d
commit 60290a9
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Showing 3 changed files with 33 additions and 2 deletions.
diff --git a/packages/fpdart/lib/src/either.dart b/packages/fpdart/lib/src/either.dart
@@ -38,6 +38,22 @@ sealed class Either<L, R> extends IEffect<Never, L, R> {
   ) =>
       value is R ? Right(value) : Left(onError(value));
 
+  static Iterable<R> getRights<L, R>(Iterable<Either<L, R>> iterable) sync* {
+    for (var either in iterable) {
+      if (either is Right<L, R>) {
+        yield either.value;
+      }
+    }
+  }
+
+  static Iterable<L> getLefts<L, R>(Iterable<Either<L, R>> iterable) sync* {
+    for (var either in iterable) {
+      if (either is Left<L, R>) {
+        yield either.value;
+      }
+    }
+  }
+
   R? toNullable();
   Option<R> toOption();
   Either<L, C> flatMap<C>(Either<L, C> Function(R r) f);

diff --git a/packages/fpdart/lib/src/extension/iterable_extension.dart b/packages/fpdart/lib/src/extension/iterable_extension.dart
@@ -11,7 +11,6 @@ import '../order.dart';
 /// If the [Iterable] is empty, return [None].
 /// {@endtemplate}
 
-/// Functional programming functions on a mutable dart [Iterable] using `fpdart`.
 extension FpdartOnIterable<T> on Iterable<T> {
   /// {@macro fpdart_iterable_extension_head}
   ///
@@ -407,8 +406,16 @@ extension FpdartOnIterable<T> on Iterable<T> {
       );
 }
 
-/// Functional programming functions on `Iterable<Iterable<T>>` using `fpdart`.
 extension FpdartOnIterableOfIterable<T> on Iterable<Iterable<T>> {
   /// From a `Iterable<Iterable<T>>` return a `Iterable<T>` of their concatenation.
   Iterable<T> get flatten => expand(identity);
 }
+
+extension FpdartSequenceIterableOption<R> on Iterable<Option<R>> {
+  Iterable<R> get getSomes => Option.getSomes(this);
+}
+
+extension FpdartSequenceIterableEither<L, R> on Iterable<Either<L, R>> {
+  Iterable<R> get getRights => Either.getRights(this);
+  Iterable<L> get getLefts => Either.getLefts(this);
+}
diff --git a/packages/fpdart/lib/src/option.dart b/packages/fpdart/lib/src/option.dart
@@ -29,6 +29,14 @@ sealed class Option<R> extends IEffect<Never, Never, R> {
     }
   }
 
+  static Iterable<R> getSomes<R>(Iterable<Option<R>> iterable) sync* {
+    for (var option in iterable) {
+      if (option is Some<R>) {
+        yield option.value;
+      }
+    }
+  }
+
   R? toNullable();
   Option<C> flatMap<C>(Option<C> Function(R r) f);