From 19f30f33ccfbc401872e142fcf42e3ac32a5b26c Mon Sep 17 00:00:00 2001
From: Timothy Clem <timothy.clem@gmail.com>
Date: Wed, 6 Jun 2018 16:17:44 -0700
Subject: [PATCH] Pull port and host from environment

---
 semantic.cabal      |  1 +
 src/Semantic/Env.hs | 15 +++++++++++++++
 2 files changed, 16 insertions(+)
 create mode 100644 src/Semantic/Env.hs

diff --git a/semantic.cabal b/semantic.cabal
index e524d64bb..590d106f9 100644
--- a/semantic.cabal
+++ b/semantic.cabal
@@ -153,6 +153,7 @@ library
                      , Semantic.CLI
                      , Semantic.Diff
                      , Semantic.Distribute
+                     , Semantic.Env
                      , Semantic.Graph
                      , Semantic.IO
                      , Semantic.Log
diff --git a/src/Semantic/Env.hs b/src/Semantic/Env.hs
new file mode 100644
index 000000000..7c93f6788
--- /dev/null
+++ b/src/Semantic/Env.hs
@@ -0,0 +1,15 @@
+module Semantic.Env where
+
+import Control.Monad.IO.Class
+import Prologue
+import System.Environment
+import Text.Read (readMaybe)
+
+envLookupHost :: MonadIO io => String -> String -> io String
+envLookupHost defaultHost k = liftIO $ fromMaybe defaultHost <$> lookupEnv k
+
+envLookupPort :: MonadIO io => Int -> String -> io Int
+envLookupPort defaultPort k = liftIO $ parsePort <$> lookupEnv k
+  where parsePort x | Just s <- x
+                    , Just p <- readMaybe s = p
+                    | otherwise = defaultPort