From c9cc0b0f2239e8d39abca471f04157e6900adb0e Mon Sep 17 00:00:00 2001
From: Matei Adriel <rafaeladriel11@gmail.com>
Date: Thu, 19 Dec 2019 14:34:48 +0200
Subject: [PATCH] typescript(option): feat: added a "flat" helper
Signed-off-by: prescientmoon <git@moonythm.dev>
---
typescript/option/README.md | 2 +-
typescript/option/src/helpers.ts | 6 +++++-
2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/typescript/option/README.md b/typescript/option/README.md
index 7aefdc9..7c24f01 100644
--- a/typescript/option/README.md
+++ b/typescript/option/README.md
@@ -16,7 +16,7 @@ npm install @adrielus/option
Curently there are no docs, but all functions have the same type definition as the ones from [fsharp](https://msdn.microsoft.com/en-us/visualfsharpdocs/conceptual/core.option-module-%5Bfsharp%5D) (except the ones from my package are not curreied)
-There are also a few original helpers (match, and withDefault), but I'ts pretty easy to guess what those do
+There are also a few original helpers (match, flat and withDefault), but I'ts pretty easy to guess what those do
# Contributing
diff --git a/typescript/option/src/helpers.ts b/typescript/option/src/helpers.ts
index 7e4017c..2351ffc 100644
--- a/typescript/option/src/helpers.ts
+++ b/typescript/option/src/helpers.ts
@@ -1,7 +1,7 @@
import { Option, Some, None } from './types'
import { Binder, Folder, Mapper, Predicate, BackFolder } from './internalTypes'
import { always, identity } from './internalHelperts'
-import Internals, { SomeClass } from './internals'
+import Internals, { SomeClass, isOption } from './internals'
export const isSome = <T>(option: Option<T>) =>
option instanceof Internals.SomeClass
@@ -89,3 +89,7 @@ export const toNullable = <T>(option: Option<T>) => {
export const withDefault = <T>(_default: T, option: Option<T>) => {
return match(option, identity, always(_default))
}
+
+export const flat = <T>(option: Option<Option<T>>) => {
+ return bind(inner => (isSome(inner) ? flat(inner) : inner), option)
+}