qr"..." delimiters) normalizes the expression -- re-orders the contents as in your examples.</p>

<p>And my attempts to requote (using <c>\"

##</code><code>##

|abd| matches |(?^u:a[bc]d)|: yes
|acd| matches |(?^u:a[bc]d)|: yes
|abcd| matches |(?^u:a[bc]d)|: no
|a[bc]d| matches |(?^u:a[bc]d)|: no