Searches forward for
Any match is returned by setting
match_start to the first character of the match and
match_end to the first character
after the match. The search will not continue past
limit. Note that a search is a linear or O(n) operation, so you may wish to use
limit to avoid locking up your UI on large buffers.
match_start will never be set to a `GtkTextIter` located before this, even if there is a
match_end after or at this.
start of search
a search string
flags affecting how the search is done
return location for start of match
return location for end of match
location of last possible
whether a match was found