sp;char&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;bool<br>
&nbsp;&nbsp;<span class="keyword">val</span>&nbsp;uppercase&nbsp;:&nbsp;string&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;string<br>
&nbsp;&nbsp;<span class="keyword">val</span>&nbsp;lowercase&nbsp;:&nbsp;string&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;string<br>
&nbsp;&nbsp;<span class="keyword">val</span>&nbsp;capitalize&nbsp;:&nbsp;string&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;string<br>
&nbsp;&nbsp;<span class="key