val</span>&nbsp;read_line&nbsp;:&nbsp;unit&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;string<br>
&nbsp;&nbsp;<span class="keyword">val</span>&nbsp;read_int&nbsp;:&nbsp;unit&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;int<br>
&nbsp;&nbsp;<span class="keyword">val</span>&nbsp;read_float&nbsp;:&nbsp;unit&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;float<br>
&nbsp;&nbsp;<span class="keyword">type</span>&nbsp;open_flag&nbsp;=<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="constructor">Open_