Availability::- use_module(library(url)).(can be autoloaded) 
 [det]url_iri(+Encoded, 
-Decoded)
[det]url_iri(-Encoded, 
+Decoded)Convert between a URL, encoding in US-ASCII and an IRI. An IRI is a 
fully expanded Unicode string. Unicode strings are first encoded into 
UTF-8, after which %-encoding takes place.
[det]url_iri(+Encoded, 
-Decoded)
[det]url_iri(-Encoded, 
+Decoded)Convert between a URL, encoding in US-ASCII and an IRI. An IRI is a 
fully expanded Unicode string. Unicode strings are first encoded into 
UTF-8, after which %-encoding takes place.