From 64cbae483000868797b8e4d50efc70a9e2873f69 Mon Sep 17 00:00:00 2001
From: Matei Adriel <rafaeladriel11@gmail.com>
Date: Thu, 19 Dec 2019 20:42:23 +0200
Subject: [PATCH] typescript(option): docs: started working on the docs

Signed-off-by: prescientmoon <git@moonythm.dev>
---
 typescript/option/README.md    |   4 +-
 typescript/option/docs/main.md | 190 +++++++++++++++++++++++++++++++++
 2 files changed, 191 insertions(+), 3 deletions(-)
 create mode 100644 typescript/option/docs/main.md

diff --git a/typescript/option/README.md b/typescript/option/README.md
index 7c24f01..734f94d 100644
--- a/typescript/option/README.md
+++ b/typescript/option/README.md
@@ -14,9 +14,7 @@ npm install @adrielus/option
 
 ## Usage
 
-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, flat and withDefault), but I'ts pretty easy to guess what those do
+For detailed usage read [the docs](docs/main.md)
 
 # Contributing
 
diff --git a/typescript/option/docs/main.md b/typescript/option/docs/main.md
new file mode 100644
index 0000000..3e0d141
--- /dev/null
+++ b/typescript/option/docs/main.md
@@ -0,0 +1,190 @@
+# Documentation
+
+## Table of contents:
+
+### General:
+
+-   [Option](#Option)
+-   [Some](#Some)
+-   [None](#None)
+
+### Helpers:
+
+-   [bind](#Bind)
+-   [count](#Count)
+-   [exists](#Exists)
+-   [filter](#Filter)
+-   [fold](#Fold)
+-   [foldback](#Foldback)
+-   [forall](#Forall)
+
+# General
+
+## Option
+
+Data type holding an optional value (can be either None or Some(x))
+
+### Signature
+
+```ts
+type Option<T> = Internals.SomeClass<T> | Internals.NoneClass
+```
+
+## None
+
+Value holding nothing
+
+### Signature
+
+```ts
+const None: Internals.NoneClass
+```
+
+## Some
+
+Creates an Option instance holding a value
+
+### Signature
+
+```ts
+const Some: <T>(v: T) => Internals.SomeClass<T>
+```
+
+### Usage
+
+```ts
+import { Some } from '@adrielus/option'
+
+Some(x) // Some(x)
+```
+
+# Helpers
+
+## Bind
+
+Invokes a function on an optional value that itself yields an option.
+
+### Signature
+
+```ts
+const bind: <T, U>(binder: Mapper<T, Option<U>>, option: Option<T>) => Option<U>
+```
+
+### Usage
+
+```ts
+import { Some, None, bind } from '@adrielus/option'
+
+const half = (x: number) => (x % 2 ? None : Some(x / 2))
+
+bind(half, Some(14)) // Some(7)
+bind(half, Some(13)) // None
+bind(half, None) // None
+```
+
+## Count
+
+Returns a zero if the option is None, a one otherwise.
+
+### Signature:
+
+```ts
+const count: <T>(option: Option<T>) => number
+```
+
+### Usage
+
+```ts
+import { Some, None, count } from '@adrielus/option'
+
+count(Some(x)) // 1
+count(None) // 0
+```
+
+## Exists
+
+Returns false if the option is None, otherwise it returns the result of applying the predicate to the option value.
+
+### Signature
+
+```ts
+const exists: <T>(predicate: Mapper<T, boolean>, option: Option<T>) => boolean
+```
+
+### Usage
+
+```ts
+import { Some, None, exists } from '@adrielus/option'
+
+exists(() => true, None) // false
+exists(() => true, Some(x)) // true
+exists(() => false, Some(x)) // false
+```
+
+## Filter
+
+Invokes a function on an optional value that itself yields an option.
+
+### Signature:
+
+```ts
+const filter: <T>(predicate: Mapper<T, boolean>, option: Option<T>) => NoneClass
+```
+
+### Usage
+
+```ts
+import { Some, None, filter } from '@adrielus/option'
+
+filter(() => true, None) // None
+filter(() => true, Some(x)) // Some(x)
+filter(() => false, Some(x)) // None
+```
+
+## Fold
+
+A function to update the state data when given a value from an option.
+
+### Signature
+
+```ts
+const fold: <T, U>(folder: Folder<T, U>, initial: U, option: Option<T>) => U
+```
+
+### Usage
+
+```ts
+import { Some, None, fold } from '@adrielus/option'
+
+const add = (a: number, b: number) => a + b
+
+fold(add, x, None) // x
+fold(add, x, Some(y)) // x + y
+```
+
+## Foldback
+
+A function to update the state data when given a value from an option.
+
+### Signature
+
+```ts
+const foldback: <T, U>(
+    folder: BackFolder<T, U>,
+    option: Option<T>,
+    initial: U
+) => U
+```
+
+### Usage
+
+```ts
+import { Some, None, foldback } from '@adrielus/option'
+
+const add = (a: number, b: number) => a + b
+
+foldback(add, None, x) // x
+foldback(add, Some(y), x) // x + y
+```
+
+**_This is still work in progress, right now only covering about 60% of the library. Contributions are welcome_**