Validation

StringKit-FP validators are practical, common-syntax checks. They are useful for early user feedback, but they are not complete RFC implementations and do not prove a remote resource exists.

ValidatorGood exampleBad exampleWhat it does not prove
IsValidEmailada@example.comada@examplethat the mailbox exists
IsValidURLhttps://example.comnot a urlthat the URL is reachable or safe
IsValidIPv4192.168.0.1256.0.0.1that a host is available
IsValidIPv62001:db8::12001:::1that an address is routed
IsValidDate2026-08-22 with yyyy-mm-dd2026-02-30every literal separator in the format

The email recipe and IP recipe are compiled examples. Treat a passing result as one input rule among any business, security, or verification steps your application requires.