X-Git-Url: http://matita.cs.unibo.it/gitweb/?p=helm.git;a=blobdiff_plain;f=helm%2FDEVEL%2Fpxp%2Fpxp%2Fdoc%2FEXTENSIONS;fp=helm%2FDEVEL%2Fpxp%2Fpxp%2Fdoc%2FEXTENSIONS;h=0000000000000000000000000000000000000000;hp=a956839100f38965981f356a472d399d578288a9;hb=3ef089a4c58fbe429dd539af6215991ecbe11ee2;hpb=1c7fb836e2af4f2f3d18afd0396701f2094265ff diff --git a/helm/DEVEL/pxp/pxp/doc/EXTENSIONS b/helm/DEVEL/pxp/pxp/doc/EXTENSIONS deleted file mode 100644 index a95683910..000000000 --- a/helm/DEVEL/pxp/pxp/doc/EXTENSIONS +++ /dev/null @@ -1,50 +0,0 @@ -****************************************************************************** -Extensions of the XML specification -****************************************************************************** - - -============================================================================== -This document -============================================================================== - -This parser has some options extending the XML specification. Here, the options -are explained. - -============================================================================== -Optional declarations instead of mandatory declarations -============================================================================== - -The XML spec demands that elements, notations, and attributes must be declared. -However, there are sometimes situations where a different rule would be better: -If there is a declaration, the actual instance of the element type, notation -reference or attribute must match the pattern of the declaration; but if the -declaration is missing, a reasonable default declaration should be assumed. - -I have an example that seems to be typical: The inclusion of HTML into a meta -language. Imagine you have defined some type of "generator" or other tool -working with HTML fragments, and your document contains two types of elements: -The generating elements (with a name like "gen:xxx"), and the object elements -which are HTML. As HTML is still evolving, you do not want to declare the HTML -elements; the HTML fragments should be treated as well-formed XML fragments. In -contrast to this, the elements of the generator should be declared and -validated because you can more easily detect errors. - -The following two processing instructions can be included into the DTD: - -- - - - References to unknown element types and notations no longer cause an error. - The element may contain everything, but it must be still well-formed. It may - have arbitrary attributes, and every attribute is treated as an #IMPLIED - CDATA attribute. - -- - - - References to unknown attributes inside one of the enumerated elements no - longer cause an error. Such an attribute is treated as an #IMPLIED CDATA - attribute. - If there are several "optional-attribute-declarations" PIs, they are all - interpreted (implicitly merged). -