Importing a module in haskell makes the code not compile : <p>I wrote the following haskell code for test. It compiles fine with <code>ghc</code> (version 8.0.2), and prints 20, as expected.</p>

<pre class="lang-hs prettyprint-override"><code>f x = x * 2

main = print $ f 10
</code></pre>

<p>But when I import <code>Char</code> module like this:</p>

<pre class="lang-hs prettyprint-override"><code>module Data.Char

f x = x * 2

main = print $ f 10
</code></pre>

<p>it gives me this error: <code>test.hs:3:1: error: parse error on input ‘f’</code>.</p>

<p>Does haskell change the environment when a module is imported? What is the difference and am I importing the module wrong?</p>
