EntityDecl(p, name$, isparm, value$, base$, sysid$, pubid$, notation$)
isparm argument will be True
if the entity is a parameter entity, False otherwise. For internal entities, e.g.
(<!ENTITY foo "bar">) |
value$ will be a string and sysid$, pubid$, and notation$ will be Nil. The
value$ string can be Nil, as well as an empty string, which is a valid value.
For external entities, value$ will be Nil and sysid$ will be a string. The
pubid$ argument will be Nil unless a public identifier was provided. The notation$
argument will have a string value only for unparsed entity declarations.
The base$ parameter will be set to whatever has been set with parser:SetBase().
If not set, it will be Nil.
True if the entity is a parameter entity