From: Samir Benmendil <me@rmz.io>
Date: Sun, 14 Jan 2018 16:26:47 +0000 (+0000)
Subject: Use do to parse numbers
X-Git-Url: https://git.rmz.io/my-scheme.git/commitdiff_plain/dc35484a906c23592e0170f051d74265ed2e8b46?ds=sidebyside

Use do to parse numbers

This is not necessarily better than the `liftM` method (probably isn't).
---

diff --git a/app/Main.hs b/app/Main.hs
index 58017c5..87b94aa 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -34,7 +34,10 @@ parseAtom = do
                 _    -> Atom atom
 
 parseNumber :: Parser LispVal
-parseNumber = liftM (Number . read) $ many1 digit
+parseNumber = do
+    ds <- many1 digit
+    let a = read ds
+    return $ Number a
 
 parseExpr :: Parser LispVal
 parseExpr = parseString