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DTD for extended pointer syntax tree (XPS-tree).
Please tell me if this
rings a bell.
The root of any XPS tree is an <xps>. In the DTD the <bridge> is
defined such that several example xps trees can be shown and parsed
in single document instance.
The DTD defines element for nodes in the XPS-tree. An element has
element content or data content; elements are never mixed with data.
If data content, the data is the value of the value property
(expressed through CONREF attributes).
Other attributes declare additional properties.
Implied attributes are NULL (empty string, i.e. no value specified).
Lexical types are defined on all attribute values through primitives and
literals. Lextype primitives:
character : any character
Regular= (.)
nonspace : any character except space
Regular= (^\s)
digit : any of '1234567890'
Regular= (\d)
name : any name in accordance with SGML declaration
Regular= ([a-zA-z0-9_.]+)
regexp : regular expression
Regular= ((.)*)
number : ('+' | '-')?, digit+
Regular= ([+-]?[01234567890]+)
numtoken : digit+, name
Regular= ([0123456789]+[a-zA-z0-9_.]+)
sqlit : ("'", character*, "'")
Regular= ("(.)*")
dqlit : ('"', character*, '"')
Regular= ('(.)*')
literal : sqlit | dqlit
Regular= ('(.)*')|("(.)*")
(implied) : Implied by governing notation
(none) : No lexical type specifications implied
Trees for patterns created out of regular expressions are decribed
in a pattern-DTD (for pattern-trees) (not supplied in this web mirror).
-->
<!--
Preamble:
Bridge element, and character data entities.
-->
<!ELEMENT bridge O O (xps*)>
<!ENTITY % characters SYSTEM "G:\ENT\PUBENT.ALL">
%characters;
<!--
Predefined navigation: Identity and root element: HERE ROOT
Examples: (here)
-->
<!ENTITY % predef "root | here">
<!ELEMENT (%predef) - O EMPTY>
<!--
nodes that directly perform a global search: ID REF
Examples: (here)
-->
<!ELEMENT id - O (#PCDATA)>
<!ATTLIST id value CDATA #CONREF
-- Reference by elements ID value
Lextype: name -->
<!ELEMENT ref - O (#PCDATA)>
<!ATTLIST ref value CDATA #CONREF
-- Canonical reference
Lextype: nonspace+ -->
<!--
Navigators are nodes that navigate into context: CHILD DESCENDANT
ANCESTOR PREVIOUS FOLLOWING NEXT.
These require a number of steps, each next step to be relative to the
previous location or navigation result.
Examples: (here)
-->
<!ELEMENT navigator - O (step)+
-- i.e. navigators step though immediate context
though 1..n steps -->
<!ATTLIST navigator dir CDATA #REQUIRED
-- lextype: 'CHILD' | 'DESCENDANT' | 'ANCESTOR' |
'PREVIOUS' | 'FOLLOWING' | 'NEXT'
-->
<!--
nodes that acces textual content of a component: PATTERN, TOKEN, STR
Examples: (here)
-->
<!ELEMENT pattern - O (#PCDATA)>
<!ATTLIST pattern value CDATA #CONREF
-- Match by regular expression
Lextype: regexp+
--
pattern CDATA #IMPLIED
-- describes .pattern property, i.e. <pattern> created
by parsing (Self value).
Lextype: (none)
-->
<!ENTITY % textaddr "token | str"
-- Match by absolute position
-->
<!ELEMENT (%textaddr) - O (number,number?)
-- i.e. 1 or 2 numbers, specifying (offset : length) -->
<!--
Location expressions in foreign notations: FOREIGN HYQ
Examples: (here)
-->
<!ENTITY % other "foreign | hyq"
-- i.e. other pointer language expressions:
FOREIGN parms, HYQ parms
-->
<!ELEMENT foreign - O (parm*)>
<!ELEMENT parm - O (#PCDATA)
-- lextype: (implied)
Each parm within a <foreign> hold the (bracketed)
parameter text for the unspecified foreign notation
-->
<!ELEMENT hyq - O (#PCDATA)>
<!ATTLIST hyq value CDATA #CONREF
-- lextype: (implied)
-->
<!--
nodes that imply a location action ('location terms')
-->
<!ENTITY % locterm " %predef | id | ref | navigator | pattern |
%textaddr | space | %other | ditto "
-- i.e. location terms -->
<!--
An expression in the extended pointer syntax is parsed into a
xps tree rooted in an <xps>, and consisting of location terms.
This is called the 'ladder' in TEI XPS.
-->
<!ELEMENT xps - O (%locterm)+ >
<!ATTLIST xps result CDATA #IMPLIED
-- informal description of xps result
Lextype: (none)
-->
<!--
A list of numbers
-->
<!ELEMENT numbers - O (number)+>
<!ELEMENT number - O (#PCDATA)>
<!ATTLIST number value CDATA #CONREF
-- lextype: number
-->
<!--
Node for addressing a section of an object in a foreign notation: SPACE
Examples: (here)
-->
<!ENTITY % pointpair "(numbers, numbers?)">
<!ELEMENT space - O (%pointpair)
-- i.e. the locations of each dimension along a
Cathesian coordinate space as named in attribute
-->
<!ATTLIST space name CDATA #REQUIRED
-- lextype: character*
i.e. name of dimension used in external data entity
-->
<!--
Node for addressing the recorded result of previous XPS query: DITTO
Examples: (here)
-->
<!ELEMENT ditto - O EMPTY
-- the current xps node. within xps element type,
valid only in TO attribute -->
<!--
Single step within navigation: criterium for selecting node.
-->
<!ELEMENT step - O (avspec*) >
<!ATTLIST step instance CDATA #REQUIRED
-- lextype: number | 'ALL'--
element CDATA #IMPLIED
-- lextype: name | '#CDATA' | '*' | regexp -->
<!--
Attribute name and attribute value to be matched on current node
See <step>.
-->
<!ELEMENT avspec - O (#PCDATA)>
<!ATTLIST avspec name CDATA #REQUIRED
-- lextype: name | '*' | regexp
--
value CDATA #CONREF
-- lextype: literal | name | number | numtoken |
'#IMPLIED' | '*' | regexp
-->