Whether the search is case sensitive.
Search by regular expressions with #GtkSourceSearchSettings:search-text as the pattern.
A search string, or %NULL if the search is disabled. If the regular expression search is enabled, #GtkSourceSearchSettings:search-text is the pattern.
For a forward search, continue at the beginning of the buffer if no search occurrence is found. For a backward search, continue at the end of the buffer.
If %TRUE, a search match must start and end a word. The match can span multiple words.