13 lines
688 B
HTML
13 lines
688 B
HTML
<h2 id="natural-transformation-examples-34">Natural Transformation Examples (3/4)</h2>
|
|
<pre><code class="haskell small">toMaybe :: [a] -> Maybe a
|
|
toMaybe [] = Nothing
|
|
toMaybe (x:xs) = Just x</pre>
|
|
</code>
|
|
<p><code>toMaybe</code> is a natural transformation. It is also a morphism from <code>[]</code> to <code>Maybe</code> in the Category of \(\Hask\) endofunctors.</p>
|
|
<img style="float:left;width:30%" src="categories/img/mp/nattrans-list-maybe.png" alt="natural transformation commutative diagram"/>
|
|
<figure style="float:right;width:60%">
|
|
<img style="width:40%" src="categories/img/mp/list-maybe-endofunctor-morphism.png" alt="natural transformation commutative diagram"/>
|
|
</figure>
|
|
|
|
|