From d7741a3374a28b37fc989f7b53c8e7065a9ec3d0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ga=C3=ABl=20Depreeuw?= <gael.depreeuw@gmail.com>
Date: Sun, 17 Jun 2018 13:16:05 +0200
Subject: [PATCH] Complete chapter 30

---
 .../30-when-things-go-wrong.md                |  5 +++++
 .../src/StoppingTheParty.hs                   | 21 +++++++++++++++++++
 2 files changed, 26 insertions(+)
 create mode 100644 30-when-things-go-wrong/30-when-things-go-wrong.md
 create mode 100644 30-when-things-go-wrong/src/StoppingTheParty.hs

diff --git a/30-when-things-go-wrong/30-when-things-go-wrong.md b/30-when-things-go-wrong/30-when-things-go-wrong.md
new file mode 100644
index 0000000..b2a0d41
--- /dev/null
+++ b/30-when-things-go-wrong/30-when-things-go-wrong.md
@@ -0,0 +1,5 @@
+# 30 When things go wrong
+
+## 30.5 The unbearable imprecision of trying
+
+see [src/StoppingTheParty.hs](./src/StoppingTheParty.hs)
\ No newline at end of file
diff --git a/30-when-things-go-wrong/src/StoppingTheParty.hs b/30-when-things-go-wrong/src/StoppingTheParty.hs
new file mode 100644
index 0000000..cef2c5e
--- /dev/null
+++ b/30-when-things-go-wrong/src/StoppingTheParty.hs
@@ -0,0 +1,21 @@
+module StoppingTheParty where
+
+import Control.Concurrent(threadDelay)
+import Control.Exception
+import Control.Monad (forever)
+import System.Random (randomRIO)
+
+randomException :: IO ()
+randomException = do
+    i <- randomRIO (1, 10 :: Int)
+    if i `elem` [1..9]
+        then throwIO DivideByZero
+        else throwIO StackOverflow
+
+main :: IO ()
+main = forever $ do
+    let tryS :: IO () -> IO (Either SomeException ())
+        tryS = try
+    _ <- tryS randomException
+    putStrLn "Live to loop another day!"
+    threadDelay (1 * 1000000)
\ No newline at end of file