fspublicsuffix's Introduction

FsPublicSuffix

Parse and separate Fully Qualified Domain Names accurately, using the Public Suffix List.

Usage

The interesting part of this library is the FullyQualifiedDomainName record type and the two parsing methods available:

FullyQualifiedDomainName.TryParse: safely parse the input string into a FQDN (returns an option)
FullyQualifiedDomainName.Parse : unsafe version of TryParse, throws an exception if the input string cannot be parsed

Here's a simple F# Interactive session that demonstrates how you can use this library:

> #load "nuget: FsPublicSuffix"
> open FsPublicSuffix

> FullyQualifiedDomainName.TryParse "www.google.co.uk"
val it : FullyQualifiedDomainName option = Some { TopLevelDomain = "co.uk"
                                                  Domain = "google"
                                                  SubDomain = Some "www" }

You can also pass full URLs as input:

> let fqdn = FullyQualifiedDomainName.Parse "https://www.youtube.com/feed/subscriptions"
val fqdn : FullyQualifiedDomainName = { TopLevelDomain = "com"
                                        Domain = "youtube"
                                        SubDomain = Some "www" }

There are two other available members:

// get the FQDN of the parsed record
fqdn.FQDN // www.youtube.com

// get the registrable domain
fqdn.Registrable // youtube.com

Here's a few more quick examples:

// non-existent TLDs are not accepted
FullyQualifiedDomainName.TryParse "google.nope" // None

// domains that cannot be registered are not accepted
FullyQualifiedDomainName.TryParse "co.uk" // None
FullyQualifiedDomainName.TryParse "uk.com" // None

// IDN and punycode are also supported
FullyQualifiedDomainName.TryParse "ουτοπία.δπθ.gr" // Some { ... }
FullyQualifiedDomainName.TryParse "xn--pxaix.gr" // Some { ... }