blank_regexp re produces a blank function from the regexp re (following the Str syntax). There is an important limitation rega- rding regular expressions containing the newline character '\n', due to the fact that the Str module only matches on strings (and not on an abstract notion of buffer). Such regular expressions can only be used if they are idempotent.

regexp ?name re g is a grammar that parses the input according to the regular expression re, and returns a value built by applying the function g to a function of type int -> string that returns the substring matched by the n-th match group of the regexp re (as in the Str module). The optional name argument is used to refer to the regular expression in error messages.