<span class="hljs-attribute">first_quote_symbol</span> = <span class="hljs-string">"'"</span> . <span class="hljs-attribute">second_quote_symbol</span> = <span class="hljs-string">'"'</span> . <span class="hljs-comment">(* escaped_quote_symbol tests backticks, which does not interfere * with backslashes. It has precedent in some language * specifications. *)</span> <span class="hljs-attribute">escaped_quote_symbol</span> = <span class="hljs-string">`\`</span> ( first_quote_symbol | second_quote_symbol ) .