From: Samir Benmendil <me@rmz.io>
Date: Sun, 14 Jan 2018 16:55:02 +0000 (+0000)
Subject: Using the "bind" operator
X-Git-Url: https://git.rmz.io/my-scheme.git/commitdiff_plain/537e327f072fb094316845a5e3105f4fbb1aa385

Using the "bind" operator

The `do..` block seems easier
---

diff --git a/app/Main.hs b/app/Main.hs
index 87b94aa..88ae7f7 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -34,10 +34,9 @@ parseAtom = do
                 _    -> Atom atom
 
 parseNumber :: Parser LispVal
-parseNumber = do
-    ds <- many1 digit
-    let a = read ds
-    return $ Number a
+parseNumber = many1 digit >>= \ ds ->
+              let a = read ds
+              in return $ Number a
 
 parseExpr :: Parser LispVal
 parseExpr = parseString