]> >> I don't know of any libraries for this purpose. I will warn anyone >> making one that it's easy for simple regex matching to evaluate the >> whole stream, and then fail to match. >> > > Or worse, never terminate. E.g., > > stream_match "a*b" (Stream.from (fun _ -> Some 'a')) > I do not see the problem in either case. If you has to match a long string you must be ready to fail. And if you are dealing with infinite data structures you must be ready not to terminate. At least these arguments did not prevent OCaml developers from implementing neither Stream nor, for example, Lexing.from_function, which definitely may be used to reproduce these malicious cases :) Best regards, DB.