Fresh start

1 files changed, 703 insertions, 0 deletions

diff --git a/jni/ruby/lib/rexml/xpath_parser.rb b/jni/ruby/lib/rexml/xpath_parser.rb
new file mode 100644
index 0000000..ef49a32
--- /dev/null
+++ b/jni/ruby/lib/rexml/xpath_parser.rb
@@ -0,0 +1,703 @@
+require 'rexml/namespace'
+require 'rexml/xmltokens'
+require 'rexml/attribute'
+require 'rexml/syncenumerator'
+require 'rexml/parsers/xpathparser'
+
+class Object
+  # provides a unified +clone+ operation, for REXML::XPathParser
+  # to use across multiple Object types
+  def dclone
+    clone
+  end
+end
+class Symbol
+  # provides a unified +clone+ operation, for REXML::XPathParser
+  # to use across multiple Object types
+  def dclone ; self ; end
+end
+class Fixnum
+  # provides a unified +clone+ operation, for REXML::XPathParser
+  # to use across multiple Object types
+  def dclone ; self ; end
+end
+class Float
+  # provides a unified +clone+ operation, for REXML::XPathParser
+  # to use across multiple Object types
+  def dclone ; self ; end
+end
+class Array
+  # provides a unified +clone+ operation, for REXML::XPathParser
+  # to use across multiple Object+ types
+  def dclone
+    klone = self.clone
+    klone.clear
+    self.each{|v| klone << v.dclone}
+    klone
+  end
+end
+
+module REXML
+  # You don't want to use this class.  Really.  Use XPath, which is a wrapper
+  # for this class.  Believe me.  You don't want to poke around in here.
+  # There is strange, dark magic at work in this code.  Beware.  Go back!  Go
+  # back while you still can!
+  class XPathParser
+    include XMLTokens
+    LITERAL    = /^'([^']*)'|^"([^"]*)"/u
+
+    def initialize( )
+      @parser = REXML::Parsers::XPathParser.new
+      @namespaces = nil
+      @variables = {}
+    end
+
+    def namespaces=( namespaces={} )
+      Functions::namespace_context = namespaces
+      @namespaces = namespaces
+    end
+
+    def variables=( vars={} )
+      Functions::variables = vars
+      @variables = vars
+    end
+
+    def parse path, nodeset
+      path_stack = @parser.parse( path )
+      match( path_stack, nodeset )
+    end
+
+    def get_first path, nodeset
+      path_stack = @parser.parse( path )
+      first( path_stack, nodeset )
+    end
+
+    def predicate path, nodeset
+      path_stack = @parser.parse( path )
+      expr( path_stack, nodeset )
+    end
+
+    def []=( variable_name, value )
+      @variables[ variable_name ] = value
+    end
+
+
+    # Performs a depth-first (document order) XPath search, and returns the
+    # first match.  This is the fastest, lightest way to return a single result.
+    #
+    # FIXME: This method is incomplete!
+    def first( path_stack, node )
+      return nil if path.size == 0
+
+      case path[0]
+      when :document
+        # do nothing
+        return first( path[1..-1], node )
+      when :child
+        for c in node.children
+          r = first( path[1..-1], c )
+          return r if r
+        end
+      when :qname
+        name = path[2]
+        if node.name == name
+          return node if path.size == 3
+          return first( path[3..-1], node )
+        else
+          return nil
+        end
+      when :descendant_or_self
+        r = first( path[1..-1], node )
+        return r if r
+        for c in node.children
+          r = first( path, c )
+          return r if r
+        end
+      when :node
+        return first( path[1..-1], node )
+      when :any
+        return first( path[1..-1], node )
+      end
+      return nil
+    end
+
+
+    def match( path_stack, nodeset )
+      r = expr( path_stack, nodeset )
+      r
+    end
+
+    private
+
+
+    # Returns a String namespace for a node, given a prefix
+    # The rules are:
+    #
+    #  1. Use the supplied namespace mapping first.
+    #  2. If no mapping was supplied, use the context node to look up the namespace
+    def get_namespace( node, prefix )
+      if @namespaces
+        return @namespaces[prefix] || ''
+      else
+        return node.namespace( prefix ) if node.node_type == :element
+        return ''
+      end
+    end
+
+
+    # Expr takes a stack of path elements and a set of nodes (either a Parent
+    # or an Array and returns an Array of matching nodes
+    ALL = [ :attribute, :element, :text, :processing_instruction, :comment ]
+    ELEMENTS = [ :element ]
+    def expr( path_stack, nodeset, context=nil )
+      node_types = ELEMENTS
+      return nodeset if path_stack.length == 0 || nodeset.length == 0
+      while path_stack.length > 0
+        if nodeset.length == 0
+          path_stack.clear
+          return []
+        end
+        case (op = path_stack.shift)
+        when :document
+          nodeset = [ nodeset[0].root_node ]
+
+        when :qname
+          prefix = path_stack.shift
+          name = path_stack.shift
+          nodeset.delete_if do |node|
+            # FIXME: This DOUBLES the time XPath searches take
+            ns = get_namespace( node, prefix )
+            if node.node_type == :element
+              if node.name == name
+              end
+            end
+            !(node.node_type == :element and
+              node.name == name and
+              node.namespace == ns )
+          end
+          node_types = ELEMENTS
+
+        when :any
+          nodeset.delete_if { |node| !node_types.include?(node.node_type) }
+
+        when :self
+          # This space left intentionally blank
+
+        when :processing_instruction
+          target = path_stack.shift
+          nodeset.delete_if do |node|
+            (node.node_type != :processing_instruction) or
+            ( target!='' and ( node.target != target ) )
+          end
+
+        when :text
+          nodeset.delete_if { |node| node.node_type != :text }
+
+        when :comment
+          nodeset.delete_if { |node| node.node_type != :comment }
+
+        when :node
+          # This space left intentionally blank
+          node_types = ALL
+
+        when :child
+          new_nodeset = []
+          nt = nil
+          nodeset.each do |node|
+            nt = node.node_type
+            new_nodeset += node.children if nt == :element or nt == :document
+          end
+          nodeset = new_nodeset
+          node_types = ELEMENTS
+
+        when :literal
+          return path_stack.shift
+
+        when :attribute
+          new_nodeset = []
+          case path_stack.shift
+          when :qname
+            prefix = path_stack.shift
+            name = path_stack.shift
+            for element in nodeset
+              if element.node_type == :element
+                attrib = element.attribute( name, get_namespace(element, prefix) )
+                new_nodeset << attrib if attrib
+              end
+            end
+          when :any
+            for element in nodeset
+              if element.node_type == :element
+                new_nodeset += element.attributes.to_a
+              end
+            end
+          end
+          nodeset = new_nodeset
+
+        when :parent
+          nodeset = nodeset.collect{|n| n.parent}.compact
+          #nodeset = expr(path_stack.dclone, nodeset.collect{|n| n.parent}.compact)
+          node_types = ELEMENTS
+
+        when :ancestor
+          new_nodeset = []
+          nodeset.each do |node|
+            while node.parent
+              node = node.parent
+              new_nodeset << node unless new_nodeset.include? node
+            end
+          end
+          nodeset = new_nodeset
+          node_types = ELEMENTS
+
+        when :ancestor_or_self
+          new_nodeset = []
+          nodeset.each do |node|
+            if node.node_type == :element
+              new_nodeset << node
+              while ( node.parent )
+                node = node.parent
+                new_nodeset << node unless new_nodeset.include? node
+              end
+            end
+          end
+          nodeset = new_nodeset
+          node_types = ELEMENTS
+
+        when :predicate
+          new_nodeset = []
+          subcontext = { :size => nodeset.size }
+          pred = path_stack.shift
+          nodeset.each_with_index { |node, index|
+            subcontext[ :node ] = node
+            subcontext[ :index ] = index+1
+            pc = pred.dclone
+            result = expr( pc, [node], subcontext )
+            result = result[0] if result.kind_of? Array and result.length == 1
+            if result.kind_of? Numeric
+              new_nodeset << node if result == (index+1)
+            elsif result.instance_of? Array
+              if result.size > 0 and result.inject(false) {|k,s| s or k}
+                new_nodeset << node if result.size > 0
+              end
+            else
+              new_nodeset << node if result
+            end
+          }
+          nodeset = new_nodeset
+=begin
+          predicate = path_stack.shift
+          ns = nodeset.clone
+          result = expr( predicate, ns )
+          if result.kind_of? Array
+            nodeset = result.zip(ns).collect{|m,n| n if m}.compact
+          else
+            nodeset = result ? nodeset : []
+          end
+=end
+
+        when :descendant_or_self
+          rv = descendant_or_self( path_stack, nodeset )
+          path_stack.clear
+          nodeset = rv
+          node_types = ELEMENTS
+
+        when :descendant
+          results = []
+          nt = nil
+          nodeset.each do |node|
+            nt = node.node_type
+            results += expr( path_stack.dclone.unshift( :descendant_or_self ),
+              node.children ) if nt == :element or nt == :document
+          end
+          nodeset = results
+          node_types = ELEMENTS
+
+        when :following_sibling
+          results = []
+          nodeset.each do |node|
+            next if node.parent.nil?
+            all_siblings = node.parent.children
+            current_index = all_siblings.index( node )
+            following_siblings = all_siblings[ current_index+1 .. -1 ]
+            results += expr( path_stack.dclone, following_siblings )
+          end
+          nodeset = results
+
+        when :preceding_sibling
+          results = []
+          nodeset.each do |node|
+            next if node.parent.nil?
+            all_siblings = node.parent.children
+            current_index = all_siblings.index( node )
+            preceding_siblings = all_siblings[ 0, current_index ].reverse
+            results += preceding_siblings
+          end
+          nodeset = results
+          node_types = ELEMENTS
+
+        when :preceding
+          new_nodeset = []
+          nodeset.each do |node|
+            new_nodeset += preceding( node )
+          end
+          nodeset = new_nodeset
+          node_types = ELEMENTS
+
+        when :following
+          new_nodeset = []
+          nodeset.each do |node|
+            new_nodeset += following( node )
+          end
+          nodeset = new_nodeset
+          node_types = ELEMENTS
+
+        when :namespace
+          new_nodeset = []
+          prefix = path_stack.shift
+          nodeset.each do |node|
+            if (node.node_type == :element or node.node_type == :attribute)
+              if @namespaces
+                namespaces = @namespaces
+              elsif (node.node_type == :element)
+                namespaces = node.namespaces
+              else
+                namespaces = node.element.namesapces
+              end
+              if (node.namespace == namespaces[prefix])
+                new_nodeset << node
+              end
+            end
+          end
+          nodeset = new_nodeset
+
+        when :variable
+          var_name = path_stack.shift
+          return @variables[ var_name ]
+
+        # :and, :or, :eq, :neq, :lt, :lteq, :gt, :gteq
+        # TODO: Special case for :or and :and -- not evaluate the right
+        # operand if the left alone determines result (i.e. is true for
+        # :or and false for :and).
+        when :eq, :neq, :lt, :lteq, :gt, :gteq, :or
+          left = expr( path_stack.shift, nodeset.dup, context )
+          right = expr( path_stack.shift, nodeset.dup, context )
+          res = equality_relational_compare( left, op, right )
+          return res
+
+        when :and
+          left = expr( path_stack.shift, nodeset.dup, context )
+          return [] unless left
+          if left.respond_to?(:inject) and !left.inject(false) {|a,b| a | b}
+            return []
+          end
+          right = expr( path_stack.shift, nodeset.dup, context )
+          res = equality_relational_compare( left, op, right )
+          return res
+
+        when :div
+          left = Functions::number(expr(path_stack.shift, nodeset, context)).to_f
+          right = Functions::number(expr(path_stack.shift, nodeset, context)).to_f
+          return (left / right)
+
+        when :mod
+          left = Functions::number(expr(path_stack.shift, nodeset, context )).to_f
+          right = Functions::number(expr(path_stack.shift, nodeset, context )).to_f
+          return (left % right)
+
+        when :mult
+          left = Functions::number(expr(path_stack.shift, nodeset, context )).to_f
+          right = Functions::number(expr(path_stack.shift, nodeset, context )).to_f
+          return (left * right)
+
+        when :plus
+          left = Functions::number(expr(path_stack.shift, nodeset, context )).to_f
+          right = Functions::number(expr(path_stack.shift, nodeset, context )).to_f
+          return (left + right)
+
+        when :minus
+          left = Functions::number(expr(path_stack.shift, nodeset, context )).to_f
+          right = Functions::number(expr(path_stack.shift, nodeset, context )).to_f
+          return (left - right)
+
+        when :union
+          left = expr( path_stack.shift, nodeset, context )
+          right = expr( path_stack.shift, nodeset, context )
+          return (left | right)
+
+        when :neg
+          res = expr( path_stack, nodeset, context )
+          return -(res.to_f)
+
+        when :not
+        when :function
+          func_name = path_stack.shift.tr('-','_')
+          arguments = path_stack.shift
+          subcontext = context ? nil : { :size => nodeset.size }
+
+          res = []
+          cont = context
+          nodeset.each_with_index { |n, i|
+            if subcontext
+              subcontext[:node]  = n
+              subcontext[:index] = i
+              cont = subcontext
+            end
+            arg_clone = arguments.dclone
+            args = arg_clone.collect { |arg|
+              expr( arg, [n], cont )
+            }
+            Functions.context = cont
+            res << Functions.send( func_name, *args )
+          }
+          return res
+
+        end
+      end # while
+      return nodeset
+    end
+
+
+    ##########################################################
+    # FIXME
+    # The next two methods are BAD MOJO!
+    # This is my achilles heel.  If anybody thinks of a better
+    # way of doing this, be my guest.  This really sucks, but
+    # it is a wonder it works at all.
+    # ########################################################
+
+    def descendant_or_self( path_stack, nodeset )
+      rs = []
+      d_o_s( path_stack, nodeset, rs )
+      document_order(rs.flatten.compact)
+      #rs.flatten.compact
+    end
+
+    def d_o_s( p, ns, r )
+      nt = nil
+      ns.each_index do |i|
+        n = ns[i]
+        x = expr( p.dclone, [ n ] )
+        nt = n.node_type
+        d_o_s( p, n.children, x ) if nt == :element or nt == :document and n.children.size > 0
+        r.concat(x) if x.size > 0
+      end
+    end
+
+
+    # Reorders an array of nodes so that they are in document order
+    # It tries to do this efficiently.
+    #
+    # FIXME: I need to get rid of this, but the issue is that most of the XPath
+    # interpreter functions as a filter, which means that we lose context going
+    # in and out of function calls.  If I knew what the index of the nodes was,
+    # I wouldn't have to do this.  Maybe add a document IDX for each node?
+    # Problems with mutable documents.  Or, rewrite everything.
+    def document_order( array_of_nodes )
+      new_arry = []
+      array_of_nodes.each { |node|
+        node_idx = []
+        np = node.node_type == :attribute ? node.element : node
+        while np.parent and np.parent.node_type == :element
+          node_idx << np.parent.index( np )
+          np = np.parent
+        end
+        new_arry << [ node_idx.reverse, node ]
+      }
+      new_arry.sort{ |s1, s2| s1[0] <=> s2[0] }.collect{ |s| s[1] }
+    end
+
+
+    def recurse( nodeset, &block )
+      for node in nodeset
+        yield node
+        recurse( node, &block ) if node.node_type == :element
+      end
+    end
+
+
+
+    # Builds a nodeset of all of the preceding nodes of the supplied node,
+    # in reverse document order
+    # preceding:: includes every element in the document that precedes this node,
+    # except for ancestors
+    def preceding( node )
+      ancestors = []
+      p = node.parent
+      while p
+        ancestors << p
+        p = p.parent
+      end
+
+      acc = []
+      p = preceding_node_of( node )
+      while p
+        if ancestors.include? p
+          ancestors.delete(p)
+        else
+          acc << p
+        end
+        p = preceding_node_of( p )
+      end
+      acc
+    end
+
+    def preceding_node_of( node )
+      psn = node.previous_sibling_node
+      if psn.nil?
+        if node.parent.nil? or node.parent.class == Document
+          return nil
+        end
+        return node.parent
+        #psn = preceding_node_of( node.parent )
+      end
+      while psn and psn.kind_of? Element and psn.children.size > 0
+        psn = psn.children[-1]
+      end
+      psn
+    end
+
+    def following( node )
+      acc = []
+      p = next_sibling_node( node )
+      while p
+        acc << p
+        p = following_node_of( p )
+      end
+      acc
+    end
+
+    def following_node_of( node )
+      if node.kind_of? Element and node.children.size > 0
+        return node.children[0]
+      end
+      return next_sibling_node(node)
+    end
+
+    def next_sibling_node(node)
+      psn = node.next_sibling_node
+      while psn.nil?
+        if node.parent.nil? or node.parent.class == Document
+          return nil
+        end
+        node = node.parent
+        psn = node.next_sibling_node
+      end
+      return psn
+    end
+
+    def norm b
+      case b
+      when true, false
+        return b
+      when 'true', 'false'
+        return Functions::boolean( b )
+      when /^\d+(\.\d+)?$/
+        return Functions::number( b )
+      else
+        return Functions::string( b )
+      end
+    end
+
+    def equality_relational_compare( set1, op, set2 )
+      if set1.kind_of? Array and set2.kind_of? Array
+        if set1.size == 1 and set2.size == 1
+          set1 = set1[0]
+          set2 = set2[0]
+        elsif set1.size == 0 or set2.size == 0
+          nd = set1.size==0 ? set2 : set1
+          rv = nd.collect { |il| compare( il, op, nil ) }
+          return rv
+        else
+          res = []
+          SyncEnumerator.new( set1, set2 ).each { |i1, i2|
+            i1 = norm( i1 )
+            i2 = norm( i2 )
+            res << compare( i1, op, i2 )
+          }
+          return res
+        end
+      end
+      # If one is nodeset and other is number, compare number to each item
+      # in nodeset s.t. number op number(string(item))
+      # If one is nodeset and other is string, compare string to each item
+      # in nodeset s.t. string op string(item)
+      # If one is nodeset and other is boolean, compare boolean to each item
+      # in nodeset s.t. boolean op boolean(item)
+      if set1.kind_of? Array or set2.kind_of? Array
+        if set1.kind_of? Array
+          a = set1
+          b = set2
+        else
+          a = set2
+          b = set1
+        end
+
+        case b
+        when true, false
+          return a.collect {|v| compare( Functions::boolean(v), op, b ) }
+        when Numeric
+          return a.collect {|v| compare( Functions::number(v), op, b )}
+        when /^\d+(\.\d+)?$/
+          b = Functions::number( b )
+          return a.collect {|v| compare( Functions::number(v), op, b )}
+        else
+          b = Functions::string( b )
+          return a.collect { |v| compare( Functions::string(v), op, b ) }
+        end
+      else
+        # If neither is nodeset,
+        #   If op is = or !=
+        #     If either boolean, convert to boolean
+        #     If either number, convert to number
+        #     Else, convert to string
+        #   Else
+        #     Convert both to numbers and compare
+        s1 = set1.to_s
+        s2 = set2.to_s
+        if s1 == 'true' or s1 == 'false' or s2 == 'true' or s2 == 'false'
+          set1 = Functions::boolean( set1 )
+          set2 = Functions::boolean( set2 )
+        else
+          if op == :eq or op == :neq
+            if s1 =~ /^\d+(\.\d+)?$/ or s2 =~ /^\d+(\.\d+)?$/
+              set1 = Functions::number( s1 )
+              set2 = Functions::number( s2 )
+            else
+              set1 = Functions::string( set1 )
+              set2 = Functions::string( set2 )
+            end
+          else
+            set1 = Functions::number( set1 )
+            set2 = Functions::number( set2 )
+          end
+        end
+        return compare( set1, op, set2 )
+      end
+      return false
+    end
+
+    def compare a, op, b
+      case op
+      when :eq
+        a == b
+      when :neq
+        a != b
+      when :lt
+        a < b
+      when :lteq
+        a <= b
+      when :gt
+        a > b
+      when :gteq
+        a >= b
+      when :and
+        a and b
+      when :or
+        a or b
+      else
+        false
+      end
+    end
+  end
+end