🚀 go-pugleaf

gtoal@tardis.computer-science.edinburgh.ac.uk writes:
|
|   I've hacked my lex parser to push back the expansion of an entity
|   ref onto the incoming text stream, so it is reparsed.  A cheap technique
|   but works OK.  Means you can have infinite recursion though if you're
|   not careful...

Remember that the only way to get "<" into a document, when followed
by a valid name start character (a-zA-Z) is to define an entity which
expands to "<", e.g. <!ENTITY lang "<" -- left angle bracket>.

If you place an "entity end" signal at the end of the expansion, it
would appear to be right, except in the cases where the entity
refereces an external entity.

lex doesn't quite cut it.  Better to write an entity manager, and
provide an interface with the following three primitives:

	-- define entity	<!ENTITY ...>
	-- invoke entity	&name; %name;
	-- read character

after syntax checking, the ENTITY markup declaration could be pushed
to the entity manger's define entity function.  Whenever a syntac-
tically legal entity reference is parsed or named, the requestor
(parser or application) calls the entity manager's invoke entity
function and reads characters until Entity end ocurs.

Putting both entity manager and parser in the same control path is
probably a bad idea due to their conceptual independence, and the fact
that even the application may need to reference entities.

--
Erik Naggum             Professional Programmer            +47-2-836-863
Naggum Software             Electronic Text             <erik@naggum.no>
0118 OSLO, NORWAY       Computer Communications        <enag@ifi.uio.no>