+-- |'Scheme' represents an URI scheme.
+type Scheme = CIAscii
+
+-- |'Host' represents an IP address or a host name in an URI
+-- authority.
+type Host = CI Text
+
+-- |'PathSegment' represents an URI path segment, split by slashes and
+-- percent-decoded.
+type PathSegment = ByteString
+
+-- |'PathSegments' is a list of URI path segments.
+type PathSegments = [PathSegment]
+