=</span> <span class="st">"/path/foo.R"</span>,</span>
<span>    start <span class="op">=</span> <span class="fl">10</span>, end <span class="op">=</span> <span class="fl">20</span>, <span class="va">...</span><span class="op">)</span></span></code></pre></div>
<p>Assuming you are editing <code>foo.R</code> very offen and the line numbers that you want to run change from time to time, you can add tags in the R script and specifying <code>start</code> and <code>end</code> by those tags. In following example 