Pattern to look for.
The default interpretation is a regular expression, as described
in stringi::stringi-search-regex. Control options with
regex()
.
Match a fixed string (i.e. by comparing only bytes), using
fixed()
. This is fast, but approximate. Generally,
for matching human text, you'll want coll()
which
respects character matching rules for the specified locale.
Match character, word, line and sentence boundaries with
boundary()
. An empty pattern, "", is equivalent to
boundary("character")
.