Pattern matching in quanteda using the valuetype argument.
the type of pattern matching: "glob" for
"glob"-style wildcard expressions; "regex" for regular expressions;
or "fixed" for exact matching. See valuetype for details.
Pattern matching in in quanteda uses "glob"-style pattern matching as the default, because this is simpler than regular expression matching while addressing most users' needs. It is also has the advantage of being identical to fixed pattern matching when the wildcard characters (`*` and `?`) are not used. Finally, most dictionary formats use glob matching.
"glob""glob"-style wildcard expressions, the quanteda default.
The implementation used in quanteda uses `*` to match any number of any
characters including none, and `?` to match any single character. See also
glob2rx and References below.
"regex"Regular expression matching.
"fixed"Fixed (literal) pattern matching.
glob2rx,
glob pattern matching (Wikipedia),
stringi-search-regex, stringi-search-fixed