> # Parsing failure
> cat(evaluate_and_highlight("1 + "))
<div class='input'>NA</div><div class='output co'>#&gt; <span class='error'>Error: &lt;text&gt;:2:0: unexpected end of input</span>
#&gt; <span class='error'>1: 1 + </span>
#&gt; <span class='error'>   ^</span></div>

> # Basic ouput
> cat(evaluate_and_highlight("# comment"))
<div class='input'><span class='co'># comment</span></div>

> cat(evaluate_and_highlight("message('x')"))
<div class='input'><span class='fu'><a href='https://rdrr.io/r/base/message.html'>message</a></span><span class='op'>(</span><span class='st'>'x'</span><span class='op'>)</span></div><div class='output co'>#&gt; <span class='message'>x</span></div>

> cat(evaluate_and_highlight("warning('x')"))
<div class='input'><span class='kw'><a href='https://rdrr.io/r/base/warning.html'>warning</a></span><span class='op'>(</span><span class='st'>'x'</span><span class='op'>)</span></div><div class='output co'>#&gt; <span class='warning'>Warning: x</span></div>

> cat(evaluate_and_highlight("stop('x', call. = FALSE)"))
<div class='input'><span class='kw'><a href='https://rdrr.io/r/base/stop.html'>stop</a></span><span class='op'>(</span><span class='st'>'x'</span>, call. <span class='op'>=</span> <span class='cn'>FALSE</span><span class='op'>)</span></div><div class='output co'>#&gt; <span class='error'>Error: x</span></div>

> # Plots
> fig_save <- (function(plot, id) list(path = paste0(id, ".png"), width = 10,
+ height = 10))
> f1 <- (function() plot(1))
> f2 <- (function() lines(0:2, 0:2))
> cat(evaluate_and_highlight("f1()\nf2()", fig_save = fig_save, env = environment()))
<div class='input'><span class='fu'>f1</span><span class='op'>(</span><span class='op'>)</span>
</div><div class='input'><span class='fu'>f2</span><span class='op'>(</span><span class='op'>)</span></div><div class='img'><img src='1.png' alt='' width='10' height='10' /></div>

