docs/ure: Document some more supported regex operators.
@@ -20,14 +20,19 @@ Supported operators are:
including negated sets (e.g. ``[^a-c]``).
``'^'``
+ Match the start of the string.
``'$'``
+ Match the end of the string.
``'?'``
+ Match zero or one of the previous entity.
``'*'``
+ Match zero or more of the previous entity.
``'+'``
+ Match one or more of the previous entity.
``'??'``
@@ -36,6 +41,7 @@ Supported operators are:
``'+?'``
``'|'``
+ Match either the LHS or the RHS of this operator.
``'(...)'``
Grouping. Each group is capturing (a substring it captures can be accessed
