REXML::Parsers::XPathParser

Class

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!

Constants

LITERAL

No documentation available

AXIS

RelativeLocationPath

|                                                    Step
  | (AXIS_NAME '::' | '@' | '')                     AxisSpecifier
    NodeTest
      Predicate
  | '.' | '..'                                      AbbreviatedStep
|  RelativeLocationPath '/' Step
| RelativeLocationPath '//' Step

PREFIX_WILDCARD

Returns a 1-1 map of the nodeset
The contents of the resulting array are either:
  true/false, if a positive match
  String, if a name match

NodeTest

| ('*' | NCNAME ':' '*' | QNAME)                NameTest
| '*' ':' NCNAME                                NameTest since XPath 2.0
| NODE_TYPE '(' ')'                             NodeType
| PI '(' LITERAL ')'                            PI
  | '[' expr ']'                                Predicate

LOCAL_NAME_WILDCARD

No documentation available

QNAME

No documentation available

NODE_TYPE

No documentation available

PI

No documentation available

VARIABLE_REFERENCE

NUMBER

No documentation available

NT

No documentation available

Instance Methods

AdditiveExpr(path, parsed)

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 443
def AdditiveExpr path, parsed
  n = []
  rest = MultiplicativeExpr( path, n )
  if rest != path
    while rest =~ /^\s*(\+|-)\s*/
      if $1[0] == ?+
        n = [ :plus, n, [] ]
      else
        n = [ :minus, n, [] ]
      end
      rest = MultiplicativeExpr( $', n[-1] )
    end
  end
  if parsed.size == 0 and n.size != 0
    parsed.replace(n)
  elsif n.size > 0
    parsed << n
  end
  rest
end

| AdditiveExpr (‘+’ | ‘-’) MultiplicativeExpr | MultiplicativeExpr

AndExpr(path, parsed)

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 376
def AndExpr path, parsed
  n = []
  rest = EqualityExpr( path, n )
  if rest != path
    while rest =~ /^\s*( and )/
      n = [ :and, n, [] ]
      rest = EqualityExpr( $', n[-1] )
    end
  end
  if parsed.size == 0 and n.size != 0
    parsed.replace(n)
  elsif n.size > 0
    parsed << n
  end
  rest
end

| AndExpr S ‘and’ S EqualityExpr | EqualityExpr

EqualityExpr(path, parsed)

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 395
def EqualityExpr path, parsed
  n = []
  rest = RelationalExpr( path, n )
  if rest != path
    while rest =~ /^\s*(!?=)\s*/
      if $1[0] == ?!
        n = [ :neq, n, [] ]
      else
        n = [ :eq, n, [] ]
      end
      rest = RelationalExpr( $', n[-1] )
    end
  end
  if parsed.size == 0 and n.size != 0
    parsed.replace(n)
  elsif n.size > 0
    parsed << n
  end
  rest
end

| EqualityExpr (‘=’ | ‘!=’) RelationalExpr | RelationalExpr

FilterExpr(path, parsed)

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 546
def FilterExpr path, parsed
  n = []
  path = PrimaryExpr( path, n )
  path = Predicate(path, n)
  parsed.concat(n)
  path
end

| FilterExpr Predicate | PrimaryExpr

FunctionCall(rest, parsed)

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 599
def FunctionCall rest, parsed
  path, arguments = parse_args(rest)
  argset = []
  for argument in arguments
    args = []
    OrExpr( argument, args )
    argset << args
  end
  parsed << argset
  path
end

| FUNCTION_NAME ‘(’ ( expr ( ‘,’ expr )* )? ‘)’

LocationPath(path, parsed)

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 187
def LocationPath path, parsed
  path = path.lstrip
  if path[0] == ?/
    parsed << :document
    if path[1] == ?/
      parsed << :descendant_or_self
      parsed << :node
      path = path[2..-1]
    else
      path = path[1..-1]
    end
  end
  return RelativeLocationPath( path, parsed ) if path.size > 0
end

LocationPath

| RelativeLocationPath
| '/' RelativeLocationPath?
| '//' RelativeLocationPath

MultiplicativeExpr(path, parsed)

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 466
def MultiplicativeExpr path, parsed
  n = []
  rest = UnaryExpr( path, n )
  if rest != path
    while rest =~ /^\s*(\*| div | mod )\s*/
      if $1[0] == ?*
        n = [ :mult, n, [] ]
      elsif $1.include?( "div" )
        n = [ :div, n, [] ]
      else
        n = [ :mod, n, [] ]
      end
      rest = UnaryExpr( $', n[-1] )
    end
  end
  if parsed.size == 0 and n.size != 0
    parsed.replace(n)
  elsif n.size > 0
    parsed << n
  end
  rest
end

| MultiplicativeExpr (‘*’ | S (‘div’ | ‘mod’) S) UnaryExpr | UnaryExpr

NodeTest(path, parsed)

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 283
def NodeTest path, parsed
  original_path = path
  path = path.lstrip
  case path
  when PREFIX_WILDCARD
    prefix = nil
    name = $1
    path = $'
    parsed << :qname
    parsed << prefix
    parsed << name
  when /^\*/
    path = $'
    parsed << :any
  when NODE_TYPE
    type = $1
    path = $'
    parsed << type.tr('-', '_').intern
  when PI
    path = $'
    literal = nil
    if path !~ /^\s*\)/
      path =~ LITERAL
      literal = $1
      path = $'
      raise ParseException.new("Missing ')' after processing instruction") if path[0] != ?)
      path = path[1..-1]
    end
    parsed << :processing_instruction
    parsed << (literal || '')
  when LOCAL_NAME_WILDCARD
    prefix = $1
    path = $'
    parsed << :namespace
    parsed << prefix
  when QNAME
    prefix = $1
    name = $2
    path = $'
    prefix = "" unless prefix
    parsed << :qname
    parsed << prefix
    parsed << name
  else
    path = original_path
  end
  return path
end

No documentation available

OrExpr(path, parsed)

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 357
def OrExpr path, parsed
  n = []
  rest = AndExpr( path, n )
  if rest != path
    while rest =~ /^\s*( or )/
      n = [ :or, n, [] ]
      rest = AndExpr( $', n[-1] )
    end
  end
  if parsed.size == 0 and n.size != 0
    parsed.replace(n)
  elsif n.size > 0
    parsed << n
  end
  rest
end

| OrExpr S ‘or’ S AndExpr | AndExpr

PathExpr(path, parsed)

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 528
def PathExpr path, parsed
  path = path.lstrip
  n = []
  rest = FilterExpr( path, n )
  if rest != path
    if rest and rest[0] == ?/
      rest = RelativeLocationPath(rest, n)
      parsed.concat(n)
      return rest
    end
  end
  rest = LocationPath(rest, n) if rest =~ /\A[\/\.\@\[\w*]/
  parsed.concat(n)
  return rest
end

| LocationPath | FilterExpr (‘/’ | ‘//’) RelativeLocationPath

Predicate(path, parsed)

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 333
def Predicate path, parsed
  original_path = path
  path = path.lstrip
  return original_path unless path[0] == ?[
  predicates = []
  while path[0] == ?[
    path, expr = get_group(path)
    predicates << expr[1..-2] if expr
  end
  predicates.each{ |pred|
    preds = []
    parsed << :predicate
    parsed << preds
    OrExpr(pred, preds)
  }
  path
end

Filters the supplied nodeset on the predicate(s)

PrimaryExpr(path, parsed)

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 562
def PrimaryExpr path, parsed
  case path
  when VARIABLE_REFERENCE
    varname = $1
    path = $'
    parsed << :variable
    parsed << varname
    #arry << @variables[ varname ]
  when /^(\w[-\w]*)(?:\()/
    fname = $1
    tmp = $'
    return path if fname =~ NT
    path = tmp
    parsed << :function
    parsed << fname
    path = FunctionCall(path, parsed)
  when NUMBER
    varname = $1.nil? ? $2 : $1
    path = $'
    parsed << :literal
    parsed << (varname.include?('.') ? varname.to_f : varname.to_i)
  when LITERAL
    varname = $1.nil? ? $2 : $1
    path = $'
    parsed << :literal
    parsed << varname
  when /^\(/                                               #/
    path, contents = get_group(path)
    contents = contents[1..-2]
    n = []
    OrExpr( contents, n )
    parsed.concat(n)
  end
  path
end

No documentation available

RelationalExpr(path, parsed)

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 418
def RelationalExpr path, parsed
  n = []
  rest = AdditiveExpr( path, n )
  if rest != path
    while rest =~ /^\s*([<>]=?)\s*/
      if $1[0] == ?<
        sym = "lt"
      else
        sym = "gt"
      end
      sym << "eq" if $1[-1] == ?=
      n = [ sym.intern, n, [] ]
      rest = AdditiveExpr( $', n[-1] )
    end
  end
  if parsed.size == 0 and n.size != 0
    parsed.replace(n)
  elsif n.size > 0
    parsed << n
  end
  rest
end

RelativeLocationPath(path, parsed)

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 211
def RelativeLocationPath path, parsed
  loop do
    original_path = path
    path = path.lstrip

    return original_path if path.empty?

    # (axis or @ or <child::>) nodetest predicate  >
    # OR                                          >  / Step
    # (. or ..)                                    >
    if path[0] == ?.
      if path[1] == ?.
        parsed << :parent
        parsed << :node
        path = path[2..-1]
      else
        parsed << :self
        parsed << :node
        path = path[1..-1]
      end
    else
      if path[0] == ?@
        parsed << :attribute
        path = path[1..-1]
        # Goto Nodetest
      elsif path =~ AXIS
        parsed << $1.tr('-','_').intern
        path = $'
        # Goto Nodetest
      else
        parsed << :child
      end

      n = []
      path = NodeTest( path, n)

      path = Predicate( path, n )

      parsed.concat(n)
    end

    original_path = path
    path = path.lstrip
    return original_path if path.empty?

    return original_path if path[0] != ?/

    if path[1] == ?/
      parsed << :descendant_or_self
      parsed << :node
      path = path[2..-1]
    else
      path = path[1..-1]
    end
  end
end

No documentation available

UnaryExpr(path, parsed)

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 491
def UnaryExpr path, parsed
  path =~ /^(\-*)/
  path = $'
  if $1 and (($1.size % 2) != 0)
    mult = -1
  else
    mult = 1
  end
  parsed << :neg if mult < 0

  n = []
  path = UnionExpr( path, n )
  parsed.concat( n )
  path
end

| ‘-’ UnaryExpr | UnionExpr

UnionExpr(path, parsed)

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 509
def UnionExpr path, parsed
  n = []
  rest = PathExpr( path, n )
  if rest != path
    while rest =~ /^\s*(\|)\s*/
      n = [ :union, n, [] ]
      rest = PathExpr( $', n[-1] )
    end
  end
  if parsed.size == 0 and n.size != 0
    parsed.replace( n )
  elsif n.size > 0
    parsed << n
  end
  rest
end

| UnionExpr ‘|’ PathExpr | PathExpr

abbreviate( path )

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 35
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

No documentation available

expand( path )

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 93
def expand( path )
  path = path.kind_of?(String) ? parse( path ) : path
  string = ""
  document = false
  while path.size > 0
    op = path.shift
    case op
    when :node
      string << "node()"
    when :attribute, :child, :following, :following_sibling,
          :ancestor, :ancestor_or_self, :descendant, :descendant_or_self,
          :namespace, :preceding, :preceding_sibling, :self, :parent
      string << "/" unless string.size == 0
      string << op.to_s.tr("_", "-")
      string << "::"
    when :any
      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| expand(x) }
      string << ']'
    when :document
      document = true
    else
      string << "/" unless string.size == 0
      string << "UNKNOWN("
      string << op.inspect
      string << ")"
    end
  end
  string = "/"+string if document
  return string
end

No documentation available

get_group(string)

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 612
def get_group string
  ind = 0
  depth = 0
  st = string[0,1]
  en = (st == "(" ? ")" : "]")
  begin
    case string[ind,1]
    when st
      depth += 1
    when en
      depth -= 1
    end
    ind += 1
  end while depth > 0 and ind < string.length
  return nil unless depth==0
  [string[ind..-1], string[0..ind-1]]
end

get_group( ‘[foo]bar’ ) -> [‘bar’, ‘[foo]’]

namespaces=( namespaces )

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 15
def namespaces=( namespaces )
  Functions::namespace_context = namespaces
  @namespaces = namespaces
end

No documentation available

parse(path)

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 20
def parse path
  path = path.dup
  path.gsub!(/([\(\[])\s+/, '\1') # Strip ignorable spaces
  path.gsub!( /\s+([\]\)])/, '\1')
  parsed = []
  OrExpr(path, parsed)
  parsed
end

No documentation available

parse_args( string )

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 630
def parse_args( string )
  arguments = []
  ind = 0
  inquot = false
  inapos = false
  depth = 1
  begin
    case string[ind]
    when ?"
      inquot = !inquot unless inapos
    when ?'
      inapos = !inapos unless inquot
    else
      unless inquot or inapos
        case string[ind]
        when ?(
          depth += 1
          if depth == 1
            string = string[1..-1]
            ind -= 1
          end
        when ?)
          depth -= 1
          if depth == 0
            s = string[0,ind].strip
            arguments << s unless s == ""
            string = string[ind+1..-1]
          end
        when ?,
          if depth == 1
            s = string[0,ind].strip
            arguments << s unless s == ""
            string = string[ind+1..-1]
            ind = -1
          end
        end
      end
    end
    ind += 1
  end while depth > 0 and ind < string.length
  return nil unless depth==0
  [string,arguments]
end

No documentation available

predicate(path)

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 29
def predicate path
  parsed = []
  Predicate( "[#{path}]", parsed )
  parsed
end

No documentation available

predicate_to_string( path ) { |path| ... }

lib/rexml/parsers/xpathparser.rb View on GitHub

          
            # File tmp/rubies/ruby-2.7.6/lib/rexml/parsers/xpathparser.rb, line 132
def predicate_to_string( path, &block )
  string = ""
  case path[0]
  when :and, :or, :mult, :plus, :minus, :neq, :eq, :lt, :gt, :lteq, :gteq, :div, :mod, :union
    op = path.shift
    case op
    when :eq
      op = "="
    when :lt
      op = "<"
    when :gt
      op = ">"
    when :lteq
      op = "<="
    when :gteq
      op = ">="
    when :neq
      op = "!="
    when :union
      op = "|"
    end
    left = predicate_to_string( path.shift, &block )
    right = predicate_to_string( path.shift, &block )
    string << " "
    string << left
    string << " "
    string << op.to_s
    string << " "
    string << right
    string << " "
  when :function
    path.shift
    name = path.shift
    string << name
    string << "( "
    string << predicate_to_string( path.shift, &block )
    string << " )"
  when :literal
    path.shift
    string << " "
    string << path.shift.inspect
    string << " "
  else
    string << " "
    string << yield( path )
    string << " "
  end
  return string.squeeze(" ")
end

No documentation available