Searches for matches to argument "regex" within each element
of a string column.
- regex regular expression
- ignore_case if ignore_case == 1, matching is case insensitive
- invert if invert == 1, identifies elements that do not match the regex
- output_logical if output_logical == 1, result will be a logical vector, otherwise returns matching positions
String representation of this Ast object in the Rapids language. For
AstPrimitives this is the name of the function; for
AstParameters this is either the name of the variable, or the
value of the numeric constant that the parameter represents. For more
complicated constructs such as AstExec or AstFunction
this method should return those objects as a Rapids string.