grep: factor out function that prints matched line with labels
Prepares for formatter support.
grep: refactor loop that yields matched text with label
As preparation for formatter support, this and the next patch split
linestate.__iter__() into two functions, line scanner and displayer.
New code uses regexp.search(str, pos) in place of regexp.search(substr),
which appears to fix a bug of highlighting.
Added signature for changeset
ccd436f7db6d
Added tag 3.9.1 for changeset
ccd436f7db6d