collapseToFirst abstract method
Collapses to the first occurrence of target
in the current range.
If there is an occurrence of target
in the characters of the current
range, then the new range contains exactly the characters of the
first such occurrence.
If there is no such occurrence, the range is not changed.
Returns true
if there is an occurrence of target
and false
if not.
Implementation
bool collapseToFirst(Characters target);