=proto
void duk_trim(duk_context *ctx, int index);

=stack
[ ... str! ... ] -> [ ... trimmed_str! ... ]

=summary
<p>Trim string at <code>index</code>.  If the value at <code>index</code> is not a
string or the index is invalid, throws an error.</p>

<p>Trimming removes white space characters from the beginning and
end the end of the string.  The result is an empty string if the string
consists entirely of white space characters.
The set of characters considered to be white space is defined by the
<a href="http://www.ecma-international.org/ecma-262/5.1/#sec-9.3.1">StrWhiteSpace</a>
production, which contains both
<a href="http://www.ecma-international.org/ecma-262/5.1/#sec-7.2">WhiteSpace</a> and
<a href="http://www.ecma-international.org/ecma-262/5.1/#sec-7.3">LineTerminator</a> characters.
The trimming behavior matches those of
<a href="http://www.ecma-international.org/ecma-262/5.1/#sec-15.5.4.20">String.prototype.trim()</a>,
<a href="http://www.ecma-international.org/ecma-262/5.1/#sec-15.1.2.2">parseInt()</a>, and
<a href="http://www.ecma-international.org/ecma-262/5.1/#sec-15.1.2.3">parseFloat()</a>.
</p>

=example
duk_trim(ctx, -3);

=tags
stack
string

=fixme
Return const char *?