From 047cc81f4f1448e182244b92848897dcf3ea77fc Mon Sep 17 00:00:00 2001
From: Rob Rix <rob.rix@github.com>
Date: Thu, 16 Jun 2016 17:34:36 -0400
Subject: [PATCH] IsField specifies a setter.

---
 src/Data/Record.hs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/Data/Record.hs b/src/Data/Record.hs
index ebbc76ebd..f4dff20ce 100644
--- a/src/Data/Record.hs
+++ b/src/Data/Record.hs
@@ -42,6 +42,7 @@ class HasField (fields :: [*]) (field :: *) where
 
 class IsField field where
   getValue :: field -> ValueOf field
+  setValue :: ValueOf field -> field
 
 
 -- Instances
@@ -66,3 +67,4 @@ type instance ValueOf ((:=>) tag value) = value
 
 instance IsField (tag :=> value) where
   getValue = unField
+  setValue = field