expandBackUntil abstract method
Expands the range to include characters back until the previous target
.
If there is an occurrence of target
in the characters preceding
the current range, the start of the the range is moved to just after
the last such occurrence.
If there is no such occurrence of target
, the end of the range is
moved to the end of source.
Returns true
if there is an occurrence of target
and false
if not.
Implementation
bool expandBackUntil(Characters target);