class REXML::Parsers::XPathParser
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
- AXIS
-
| Step | (AXIS_NAME '::' | '@' | '') AxisSpecifier NodeTest Predicate | '.' | '..' AbbreviatedStep | RelativeLocationPath '/' Step | RelativeLocationPath '//' Step
- LITERAL
- LOCAL_NAME_WILDCARD
- NODE_TYPE
- NT
- NUMBER
- PI
- 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
| ('*' | NCNAME ':' '*' | QNAME) NameTest | '*' ':' NCNAME NameTest since XPath 2.0 | NODE_TYPE '(' ')' NodeType | PI '(' LITERAL ')' PI | '[' expr ']' Predicate
- QNAME
- VARIABLE_REFERENCE
|
VARIABLE_REFERENCE
| ‘(’ expr ‘)’ |LITERAL
|NUMBER
|FunctionCall
Public Instance Methods
# File rexml-3.2.5/lib/rexml/parsers/xpathparser.rb, line 41 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
# File rexml-3.2.5/lib/rexml/parsers/xpathparser.rb, line 99 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
# File rexml-3.2.5/lib/rexml/parsers/xpathparser.rb, line 15 def namespaces=( namespaces ) Functions::namespace_context = namespaces @namespaces = namespaces end
# File rexml-3.2.5/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 = [] rest = OrExpr(path, parsed) if rest unless rest.strip.empty? raise ParseException.new("Garbage component exists at the end: " + "<#{rest}>: <#{path}>") end end parsed end
# File rexml-3.2.5/lib/rexml/parsers/xpathparser.rb, line 35 def predicate path parsed = [] Predicate( "[#{path}]", parsed ) parsed end
# File rexml-3.2.5/lib/rexml/parsers/xpathparser.rb, line 138 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
Private Instance Methods
| AdditiveExpr
(‘+’ | ‘-’) MultiplicativeExpr
| MultiplicativeExpr
# File rexml-3.2.5/lib/rexml/parsers/xpathparser.rb, line 455 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
| AndExpr
S ‘and’ S EqualityExpr
| EqualityExpr
# File rexml-3.2.5/lib/rexml/parsers/xpathparser.rb, line 388 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
| EqualityExpr
(‘=’ | ‘!=’) RelationalExpr
| RelationalExpr
# File rexml-3.2.5/lib/rexml/parsers/xpathparser.rb, line 407 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
| FilterExpr
Predicate
| PrimaryExpr
# File rexml-3.2.5/lib/rexml/parsers/xpathparser.rb, line 558 def FilterExpr path, parsed n = [] path_before_primary_expr = path path = PrimaryExpr(path, n) return path_before_primary_expr if path == path_before_primary_expr path = Predicate(path, n) parsed.concat(n) path end
| FUNCTION_NAME ‘(’ ( expr ( ‘,’ expr )* )? ‘)’
# File rexml-3.2.5/lib/rexml/parsers/xpathparser.rb, line 613 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
| RelativeLocationPath | '/' RelativeLocationPath? | '//' RelativeLocationPath
# File rexml-3.2.5/lib/rexml/parsers/xpathparser.rb, line 193 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
| MultiplicativeExpr
(‘*’ | S (‘div’ | ‘mod’) S) UnaryExpr
| UnaryExpr
# File rexml-3.2.5/lib/rexml/parsers/xpathparser.rb, line 478 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
# File rexml-3.2.5/lib/rexml/parsers/xpathparser.rb, line 293 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 = $' else 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
| OrExpr
S ‘or’ S AndExpr
| AndExpr
# File rexml-3.2.5/lib/rexml/parsers/xpathparser.rb, line 369 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
| LocationPath
| FilterExpr
(‘/’ | ‘//’) RelativeLocationPath
# File rexml-3.2.5/lib/rexml/parsers/xpathparser.rb, line 540 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
Filters the supplied nodeset on the predicate(s)
# File rexml-3.2.5/lib/rexml/parsers/xpathparser.rb, line 345 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
# File rexml-3.2.5/lib/rexml/parsers/xpathparser.rb, line 576 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
| RelationalExpr
(‘<’ | ‘>’ | ‘<=’ | ‘>=’) AdditiveExpr
| AdditiveExpr
# File rexml-3.2.5/lib/rexml/parsers/xpathparser.rb, line 430 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
# File rexml-3.2.5/lib/rexml/parsers/xpathparser.rb, line 217 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 path_before_axis_specifier = path parsed_not_abberviated = [] if path[0] == ?@ parsed_not_abberviated << :attribute path = path[1..-1] # Goto Nodetest elsif path =~ AXIS parsed_not_abberviated << $1.tr('-','_').intern path = $' # Goto Nodetest else parsed_not_abberviated << :child end path_before_node_test = path path = NodeTest(path, parsed_not_abberviated) if path == path_before_node_test return path_before_axis_specifier end path = Predicate(path, parsed_not_abberviated) parsed.concat(parsed_not_abberviated) 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
| UnionExpr
‘|’ PathExpr
| PathExpr
# File rexml-3.2.5/lib/rexml/parsers/xpathparser.rb, line 521 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
get_group
( ‘[foo]bar’ ) -> [‘bar’, ‘[foo]’]
# File rexml-3.2.5/lib/rexml/parsers/xpathparser.rb, line 626 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
# File rexml-3.2.5/lib/rexml/parsers/xpathparser.rb, line 644 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