From a874a79970383f8b50713e4f59f9b069a54e8fdb Mon Sep 17 00:00:00 2001
From: Pete Johanson <peter@peterjohanson.com>
Date: Mon, 30 Oct 2017 19:41:37 -0400
Subject: [PATCH] Add Option.bindLens function.

---
 src/Freya.Core/Prelude.fs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/Freya.Core/Prelude.fs b/src/Freya.Core/Prelude.fs
index 9555c4b..6b6ecf5 100644
--- a/src/Freya.Core/Prelude.fs
+++ b/src/Freya.Core/Prelude.fs
@@ -109,6 +109,9 @@ module Option =
     let mapLens (l: Lens<'a,'b>) : Prism<'a option,'b> =
         Option.map (fst l), snd l >> Option.map
 
+    let bindLens (p : Lens<'a, 'b option>) : Lens<'a option, 'b option> =
+        Option.bind (fst p), snd p >> Option.map
+
 // Constants
 
 /// Literal constants for the values of keys within the OWIN environment,
@@ -309,4 +312,4 @@ module Constants =
         let [<Literal>] ClientCloseStatus = "websocket.ClientCloseStatus"
 
         [<CompiledName ("ClientCloseDescription")>]
-        let [<Literal>] ClientCloseDescription = "websocket.ClientCloseDescription"
\ No newline at end of file
+        let [<Literal>] ClientCloseDescription = "websocket.ClientCloseDescription"