category-theory-presentation/categories/30_How/030_Haskell_Kinds.html
2013-02-28 16:49:12 +01:00

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<h2 id="haskell-kinds">Haskell Kinds</h2>
<p>In Haskell some types can take type variable(s). Typically: <code>[a]</code>.</p>
<p>Types have <em>kinds</em>; The kind is to type what type is to function. Kind are the types for types (so meta).</p>
<pre><code>Int, Char :: *
[], Maybe :: * -&gt; *
(,) :: * -&gt; * -&gt; *
[Int], Maybe Char, Maybe [Int] :: *</code></pre>