"oops"

darcs-hash:124414697b6eca4a749814989db32489946b1315

Fixed xnum parsing / unparsing.
Fixed comparison operators.
Added lang() function.
Node sets returned by EVALUATE and EVALUATE-COMPILED now are automatically sorted
using document order by default.
Fixed following:: axis (again).
Fixed NODE-TEST-NAME for namespace nodes.
Numbers in XPath expressions are now never parsed into SINGLE-FLOAT.
Added SORT-NODE-SET function.

darcs-hash:f11136c9917dee6bd41d96f3e8950db389c78b55

darcs-hash:d40b75c09b911dc74c448e12734de19df206bb38

darcs-hash:d3828b9c30d4ea787fb181678a3db979fbd16f09

A new function EVALUATE is provided that...
  - automatically parses XPath strings.
  - also accepts sexps in the syntax (xpath (sexp-goes-here)).  (The special
    marker XPATH in the CAR is needed to distinguish literal strings from XPath
    strings.)
  - and accepts pre-compiled closures.  Users who want to use this function
    with a customized environment must pass precompiled closures.

For the first two cases, the environment is defined lexically using the
new macro WITH-NAMESPACES.

The context argument to ALL-NODES can be either...
  - an actual context
  - or any other node understood by the XPath protocol, and will then
    be turned into a trivial context automatically

A compiler macro on EVALUATE allows pre-compilation of closures at fasl
load time.  (Macrolet tricks propagate the information from WITH-NAMESPACES
into the compiler macro.  Thanks to chandler on #lisp for the tip.)

darcs-hash:88c7a7985b99372e14071fb9eb8da0bc97d0b054

darcs-hash:2d8860ef9e911e6597859b4fa6ea89a4138523bc

functions.lisp
        - new function XPATH:UNION for the | operator
          (not a keyword because not technically an XPath function)

lexer.lisp
	Lots of fixes.

node-tests.lisp
	- NODE-TEST-NAME
	  Added the namespace URI as an optional second argument.
	- NODE-TEST-NAMESPACE
	  New, checks only the namespace and not the local name.
	- NODE-TEST-PROCESSING-INSTRUCTION
	  Added the name to check as an optional argument.

types.lisp
	- CONTEXT-VARIABLE-VALUE
	  New generic function looking up variable values during
	  evaluation.
	- ENVIRONMENT
	  New struct, basically a compilation-time context.
	- ENVIRONMENT-FIND-NAMESPACE
	  New generic function for prefix -> uri lookups
	- ENVIRONMENT-FIND-FUNCTION
	  New generic function for (local-name uri) -> function lookups.
	- ENVIRONMENT-VALIDATE-VARIABLE
	  New generic function that returns true if the variable is
	  declared.
	- TEST-ENVIRONMENT
	  An environment that pretends to know about every namespace,
	  function, and variable. For use only in parser tests.

xpath.lisp

	- MAKE-LOCATION-STEP
	  Now accepts the list of predicates instead of just one
	  predicate.
	- COMPILE-PREDICATES
	  helper function for make-location-step
 	- DECODE-QNAME, FIND-NAMESPACE
	  New
	- COMPILE-XPATH
	    * New second argument `environment'.
	    * For function calls, check if the function name is a string
	      rather than a symbol, and if so, look it up in the enviroment.
	    * New: variables
	    * New: filters
	- COMPILE-VARIABLE
	  New
	- COMPILE-NODE-TEST
	  Split qnames.  And allow lists as node-tests to handle
	  :namespace, named :processing-instruction, and pre-parsed :qname
	- COMPILE-LOCATION-STEP
	    * New second argument `environment'.
	    * Accept multiple predicates.
	- COMPILE-PATH
	  New second argument `environment'.
	- COMPILE-FILTER-PATH
	  New

axis.lisp
	- new axis :namespace
	- new axis :following-sibling
	- new axis :preceding-sibling
	- new axis :following
	- new axis :preceding
	- new axis :ancestor-or-self
	and
	- pseudo axis :root  -- FIXME: is this right?

darcs-hash:828be75c0208ef166e480cfe33eb83b3ac57f285

darcs-hash:b96e13c8d54121d1fbfffc220ff442053e425942