def abbreviate( path )
path = path.kind_of?(String) ? parse( path ) : path
string = ""
document = false
while path.size > 0
op = path.shift
case op
when :node
when :attribute
string << "/" if string.size > 0
string << "@"
when :child
string << "/" if string.size > 0
when :descendant_or_self
string << "/"
when :self
string << "."
when :parent
string << ".."
when :any
string << "*"
when :text
string << "text()"
when :following, :following_sibling,
:ancestor, :ancestor_or_self, :descendant,
:namespace, :preceding, :preceding_sibling
string << "/" unless string.size == 0
string << op.to_s.tr("_", "-")
string << "::"
when :qname
prefix = path.shift
name = path.shift
string << prefix+":" if prefix.size > 0
string << name
when :predicate
string << '['
string << predicate_to_string( path.shift ) {|x| abbreviate( x ) }
string << ']'
when :document
document = true
when :function
string << path.shift
string << "( "
string << predicate_to_string( path.shift[0] ) {|x| abbreviate( x )}
string << " )"
when :literal
string << %Q{ "#{path.shift}" }
else
string << "/" unless string.size == 0
string << "UNKNOWN("
string << op.inspect
string << ")"
end
end
string = "/"+string if document
return string
end