function
Returns: the alternative URI
export string function map-uri via value entity-resolver resolver from value string uri
Function map-uri attempts to map one URI to another, as specified by the resolver. If
the resolver does not specify a replacement URI, this function will throw resolution-failure .
The function is used by read-entity , which falls back to the original URI if map-uri fails
with resolution-failure . Through read-entity , map-uri is also indirectly invoked by
external-entity-resolver , external-entities-resolved , and parse-entity . It thus provides a
central place to override the entire behaviour of the default entity-resolver .