-  uri_encoded(+Component, +Value, -Encoded:atom) is det
- uri_encoded(+Component, -Value:atom, +Encoded) is det
- Encoded is the URI encoding for Value. When encoding
(Value->Encoded), Component specifies the URI component where the
value is used. It is one of query_value,fragment,pathorsegment. Besides alphanumerical characters, the following
characters are passed verbatim (the set is split in logical groups
according to RFC3986).
- query_value, fragment
- 
"-._~" | "!$'()*,;" | "@" | "/?"
- path
- 
"-._~" | "!$&'()*,;=" | "@" | "/"
- segment
- 
"-._~" | "!$&'()*,;=" | "@"