From e51fb7c1416ed3438d76461dddeab148dd107645 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Avi=20=D7=93?= <avi.the.coder@gmail.com>
Date: Sun, 23 Dec 2018 09:28:13 -0500
Subject: [PATCH] Add and_then methods for EitherOrBoth

---
 src/either_or_both.rs | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/src/either_or_both.rs b/src/either_or_both.rs
index f242a7846..5c5b711b6 100644
--- a/src/either_or_both.rs
+++ b/src/either_or_both.rs
@@ -132,4 +132,28 @@ impl<A, B> EitherOrBoth<A, B> {
             Both(a, b) => Both(f(a), g(b)),
         }
     }
+
+    /// Apply the function `f` on the value `b` in `Right(b)` or `Both(a, _)` variants if it is
+    /// present.
+    pub fn left_and_then<F, L>(self, f: F) -> EitherOrBoth<L, B>
+    where
+        F: FnOnce(A) -> EitherOrBoth<L, B>,
+    {
+        match self {
+            Left(a) | Both(a, _) => f(a),
+            Right(b) => Right(b),
+        }
+    }
+
+    /// Apply the function `f` on the value `a`
+    /// in `Left(a)` or `Both(a, _)` variants if it is present.
+    pub fn right_and_then<F, R>(self, f: F) -> EitherOrBoth<A, R>
+    where
+        F: FnOnce(B) -> EitherOrBoth<A, R>,
+    {
+        match self {
+            Left(a) => Left(a),
+            Right(b) | Both(_, b) => f(b),
+        }
+    }
 }