private static void DecodeName(Axis node, StringBuilder expr) {
string name = node.Name;
if (name == null || name.Length == 0) {
expr.Append(s_Star);
}
else {
string prefix = node.Prefix;
if (prefix != null && prefix.Length > 0) {
expr.Append(prefix);
expr.Append(s_Colon);
}
expr.Append(name);
}
}
private static void DecodeNodeTest(Axis node, StringBuilder expr) {
switch (node.Type) {
case XPathNodeType.Element:
case XPathNodeType.Attribute:
DecodeName(node, expr);
break;
case XPathNodeType.Text:
expr.Append(s_Text);
break;
case XPathNodeType.ProcessingInstruction:
expr.Append(s_ProcessingInstruction);
expr.Append(s_LParens);
string name = node.Name;
if (name != null && name.Length > 0)
expr.Append(name);
expr.Append(s_RParens);
break;
case XPathNodeType.Comment:
expr.Append(s_Comment);
break;
case XPathNodeType.All:
expr.Append(s_Node);
break;
default:
Debug.Fail("Unexpected node type in axis");
break;
}
}
//>> NodeTest ::= NameTest | 'comment ()' | 'text ()' | 'node ()' | 'processing-instruction (' Literal ? ')'
private AstNode ParseNodeTest(AstNode qyInput, Axis.AxisType axisType, XPathNodeType nodeType) {
string nodeName, nodePrefix;
switch (this.scanner.Kind) {
case XPathScanner.LexKind.Name :
if (this.scanner.CanBeFunction && IsNodeType(this.scanner)) {
nodePrefix = string.Empty;
nodeName = string.Empty;
nodeType = (
this.scanner.Name == "comment" ? XPathNodeType.Comment :
this.scanner.Name == "text" ? XPathNodeType.Text :
this.scanner.Name == "node" ? XPathNodeType.All :
this.scanner.Name == "processing-instruction" ? XPathNodeType.ProcessingInstruction :
/* default: */ XPathNodeType.Root
);
Debug.Assert(nodeType != XPathNodeType.Root);
NextLex();
PassToken(XPathScanner.LexKind.LParens);
if (nodeType == XPathNodeType.ProcessingInstruction) {
if (this.scanner.Kind != XPathScanner.LexKind.RParens) { //>> 'processing-instruction (' Literal ')'
CheckToken(XPathScanner.LexKind.String);
nodeName = this.scanner.StringValue;
NextLex();
}
}
PassToken(XPathScanner.LexKind.RParens);
}
else {
nodePrefix = this.scanner.Prefix;
nodeName = this.scanner.Name;
NextLex();
if (nodeName == "*") {
nodeName = string.Empty;
}
}
break;
case XPathScanner.LexKind.Star :
nodePrefix = string.Empty;
nodeName = string.Empty;
NextLex();
break;
default :
throw new XPathException(Res.Xp_NodeSetExpected, this.scanner.SourceText);
}
return new Axis(axisType, qyInput, nodePrefix, nodeName, nodeType);
}
//>> LocationPathPattern ::= '/' | RelativePathPattern | '//' RelativePathPattern | '/' RelativePathPattern
//>> | IdKeyPattern (('/' | '//') RelativePathPattern)?
private AstNode ParseLocationPathPattern(AstNode qyInput) {
AstNode opnd = null;
switch (this.scanner.Kind) {
case XPathScanner.LexKind.Slash :
NextLex();
opnd = new Root();
if (this.scanner.Kind == XPathScanner.LexKind.Eof || this.scanner.Kind == XPathScanner.LexKind.Union) {
return opnd;
}
break;
case XPathScanner.LexKind.SlashSlash :
NextLex();
opnd = new Axis(Axis.AxisType.DescendantOrSelf, new Root());
break;
case XPathScanner.LexKind.Name :
if (this.scanner.CanBeFunction) {
opnd = ParseIdKeyPattern(qyInput);
if (opnd != null) {
switch (this.scanner.Kind) {
case XPathScanner.LexKind.Slash :
NextLex();
break;
case XPathScanner.LexKind.SlashSlash :
NextLex();
opnd = new Axis(Axis.AxisType.DescendantOrSelf, opnd);
break;
default :
return opnd;
}
}
}
break;
}
return ParseRelativePathPattern(opnd);
}
// depending on axis.Name & axis.Prefix, i will set the axis._urn;
// also, record urn from prefix during this
// 4 different types of element or attribute (with @ before it) combinations:
// (1) a:b (2) b (3) * (4) a:*
// i will check xpath to be strictly conformed from these forms
// for (1) & (4) i will have URN set properly
// for (2) the URN is null
// for (3) the URN is empty
private void SetURN (Axis axis, XmlNamespaceManager nsmgr) {
if (axis.Prefix != String.Empty) { // (1) (4)
XmlNameTable nameTable = nsmgr.NameTable;
if (nameTable != null) {
axis._urn = nsmgr.LookupNamespace(nsmgr.NameTable.Get(axis.Prefix));
}
else {
axis._urn = nsmgr.LookupNamespace(axis.Prefix);
}
// axis._urn = prefix == null ? null : nsmgr.LookupNamespace(prefix);
// wrong prefix, throw exceptions
if (axis._urn == null) {
throw new XmlSchemaException(Res.Sch_UnresolvedPrefix, axis.Prefix);
}
}
else if (axis.Name != String.Empty) { // (2)
axis._urn = null;
}
else { // (3)
axis._urn = "";
}
}
//>> Step ::= '.' | '..' | ( AxisName '::' | '@' )? NodeTest Predicate*
private AstNode ParseStep(AstNode qyInput) {
AstNode opnd;
if (XPathScanner.LexKind.Dot == this.scanner.Kind) { //>> '.'
NextLex();
opnd = new Axis(Axis.AxisType.Self, qyInput);
}
else if (XPathScanner.LexKind.DotDot == this.scanner.Kind) { //>> '..'
NextLex();
opnd = new Axis(Axis.AxisType.Parent, qyInput);
}
else { //>> ( AxisName '::' | '@' )? NodeTest Predicate*
Axis.AxisType axisType = Axis.AxisType.Child;
switch (this.scanner.Kind) {
case XPathScanner.LexKind.At: //>> '@'
axisType = Axis.AxisType.Attribute;
NextLex();
break;
case XPathScanner.LexKind.Axe: //>> AxisName '::'
axisType = GetAxis(this.scanner);
NextLex();
break;
}
XPathNodeType nodeType = (
axisType == Axis.AxisType.Attribute ? XPathNodeType.Attribute :
// axisType == Axis.AxisType.Namespace ? XPathNodeType.Namespace : // No Idea why it's this way but othervise Axes doesn't work
/* default: */ XPathNodeType.Element
);
opnd = ParseNodeTest(qyInput, axisType, nodeType);
while (XPathScanner.LexKind.LBracket == this.scanner.Kind) {
opnd = new Filter(opnd, ParsePredicate(opnd));
}
}
return opnd;
}
private static bool IsDescendantOrSelf(Axis ast) {
return ((ast.TypeOfAxis == Axis.AxisType.DescendantOrSelf) && (ast.Type == XPathNodeType.All) && (ast.abbrAxis));
}
private IQuery ProcessNode(AstNode root, IQuery qyInput,int parent,
Axis.AxisType parentaxis, ref bool cache, ref bool position) {
IQuery result = null;
if (root == null)
return null;
switch (root.TypeOfAst) {
case AstNode.QueryType.Axis:
filterCount = 0;
firstInput = null;
Axis axis = (Axis)root;
if (axis.TypeOfAxis == Axis.AxisType.Descendant || axis.TypeOfAxis ==
Axis.AxisType.DescendantOrSelf)
if (_smart > 0) {
result = ProcessAxis(
axis,
ProcessNode(axis.Input,
qyInput,Smart_D,
axis.TypeOfAxis, ref cache, ref position),
parent, parentaxis);
break;
}
_smart++;
result = ProcessAxis(
axis,
ProcessNode(axis.Input,
qyInput,Regular_D,
axis.TypeOfAxis, ref cache, ref position),
parent, parentaxis);
_smart--;
break;
case AstNode.QueryType.Operator:
_smart = 2;
result = ProcessOperator((Operator)root, null, ref cache, ref position);
break;
case AstNode.QueryType.Filter:
_smart = 2;
result = ProcessFilter((Filter)root, ref cache, ref position);
break;
case AstNode.QueryType.ConstantOperand:
result = ProcessOperand((Operand)root);
break;
case AstNode.QueryType.Variable:
result = ProcessVariable((Variable)root);
break;
case AstNode.QueryType.Function:
result = ProcessFunction(
(System.Xml.XPath.Function)root,
qyInput, ref cache, ref position);
break;
case AstNode.QueryType.Group:
_smart = 2;
result = new GroupQuery(ProcessNode(
((System.Xml.XPath.Group)root).GroupNode,
qyInput,Regular_D,
Axis.AxisType.None,
ref cache, ref position));
break;
case AstNode.QueryType.Root:
result = new AbsoluteQuery();
break;
default:
Debug.Assert(false, "Unknown QueryType encountered!!");
break;
}
return result;
}
// this part is for parsing restricted xpath from grammar
private static bool IsNameTest(Axis ast) {
// Type = Element, abbrAxis = false
// all are the same, has child:: or not
return ((ast.TypeOfAxis == Axis.AxisType.Child) && (ast.Type == XPathNodeType.Element));
}
internal static bool IsAttribute(Axis ast) {
return ((ast.TypeOfAxis == Axis.AxisType.Attribute) && (ast.Type == XPathNodeType.Attribute));
}
// recursive here
internal static DoubleLinkAxis ConvertTree (Axis axis) {
if (axis == null) {
return null;
}
return ( new DoubleLinkAxis (axis, ConvertTree ((Axis) (axis.Input))));
}
//constructor
internal DoubleLinkAxis (Axis axis, DoubleLinkAxis inputaxis) {
this.next = null;
this._input = inputaxis;
this._urn = axis.URN;
this._prefix = axis.Prefix;
this._name = axis.Name;
this._nodetype = axis.Type;
this._axistype = axis.TypeOfAxis;
this.abbrAxis = axis.abbrAxis;
if (inputaxis != null) {
inputaxis.Next = this;
}
}
//constructor
// I can't recrusively call constructor -- "No overload for method 'Axis' takes '0' arguments"
// or assign value to 'this' -- "Cannot assign to '<this>' because it is read-only"
//constructor
internal DoubleLinkAxis ( Axis input,
Axis next,
String urn,
String prefix,
String name,
XPathNodeType nodetype,
AxisType axistype,
bool abbrAxis ) {
this._input = input;
this.next = next;
this._urn = urn;
this._prefix = prefix;
this._name = name;
this._nodetype = nodetype;
this._axistype = axistype;
this.abbrAxis = abbrAxis;
}
private static void DecodeAxis(Axis node, StringBuilder expr) {
string axis = String.Empty;
switch (node.TypeOfAxis) {
case Axis.AxisType.Ancestor: axis = s_Ancestor; break;
case Axis.AxisType.AncestorOrSelf: axis = s_AncestorOrSelf; break;
case Axis.AxisType.Attribute: axis = s_Attribute; break;
case Axis.AxisType.Child: break;
case Axis.AxisType.Descendant: axis = s_Descendant; break;
case Axis.AxisType.DescendantOrSelf: if (node.abbrAxis) {
return;
}
axis = s_DescendantOrSelf; break;
case Axis.AxisType.Following: axis = s_Following; break;
case Axis.AxisType.FollowingSibling: axis = s_FollowingSibling; break;
case Axis.AxisType.Namespace: axis = s_Namespace; break;
case Axis.AxisType.Parent: axis = s_Parent; break;
case Axis.AxisType.Preceding: axis = s_Preceding; break;
case Axis.AxisType.PrecedingSibling: axis = s_PrecedingSibling; break;
case Axis.AxisType.Self: axis = s_Self; break;
case Axis.AxisType.None: break;
default:
Debug.Fail("Unexpected Type Of Axis");
break;
}
expr.Append(axis);
DecodeNodeTest(node, expr);
}
internal static bool IsSelf(Axis ast) {
return ((ast.TypeOfAxis == Axis.AxisType.Self) && (ast.Type == XPathNodeType.All) && (ast.abbrAxis));
}
private static void ComposeAxis(Axis node, StringBuilder expr) {
if (node.Input != null) {
ComposeExpression(node.Input, expr);
if (node.Input.TypeOfAst == AstNode.QueryType.Axis) {
expr.Append(s_Slash);
}
}
DecodeAxis(node, expr);
}
private IQuery ProcessAxis(Axis root , IQuery qyInput, int parent, Axis.AxisType parentaxis) {
IQuery result = null;
String URN = String.Empty;
if ( root.Prefix.Length > 0) {
_hasPrefix = true;
}
hasReverseAxis = false;
switch (root.TypeOfAxis) {
case Axis.AxisType.Ancestor:
result = new XPathAncestorQuery( qyInput , false, root.Name, root.Prefix, URN, root.Type );
_specialAxis = hasReverseAxis = true;
break;
case Axis.AxisType.AncestorOrSelf:
result = new XPathAncestorQuery( qyInput, true, root.Name, root.Prefix, URN, root.Type );
_specialAxis = hasReverseAxis = true;
break;
case Axis.AxisType.Child:
if (_slashslash){
result = new XPathDescendantQuery( qyInput, false, root.Name, root.Prefix, URN, root.Type, abbrAxis);
if (_specialAxis || (qyInput != null && (int)qyInput.getName() > (int) Querytype.Self)) {
result = new CacheQuery(result);
}
_slashslash = false;
_specialAxis = true;
break;
}
if (_specialAxis || (qyInput != null && (int)qyInput.getName() > (int) Querytype.Self))
result = new CacheChildrenQuery( qyInput, root.Name, root.Prefix, URN, root.Type );
else
result = new ChildrenQuery( qyInput, root.Name, root.Prefix, URN, root.Type );
break;
case Axis.AxisType.Parent:
result = new ParentQuery( qyInput, root.Name, root.Prefix, URN, root.Type );
break;
case Axis.AxisType.Descendant:
switch (parent) {
case Smart_D :
result = new SmartXPathDescendantQuery( qyInput, false, root.Name, root.Prefix, URN, root.Type);
break;
case Regular_D :
result = new XPathDescendantQuery(qyInput, false, root.Name, root.Prefix, URN, root.Type);
if (_specialAxis || (qyInput != null && (int)qyInput.getName() > (int) Querytype.Self))
result = new CacheQuery(result);
_specialAxis = true;
break;
}
break;
case Axis.AxisType.DescendantOrSelf:
switch (parent) {
case Smart_D :
result = new SmartXPathDescendantQuery(qyInput, true, root.Name, root.Prefix, URN, root.Type, root.abbrAxis);
break;
case Regular_D :
if ( _smart <= 1 || root.Type != XPathNodeType.All ||
parentaxis != Axis.AxisType.Child) {
result = new XPathDescendantQuery(
qyInput,
true,
root.Name,
root.Prefix,
URN,
root.Type,
root.abbrAxis);
if (_specialAxis || (qyInput != null && (int)qyInput.getName() > (int) Querytype.Self))
result = new CacheQuery(result);
_specialAxis = true;
}
else
{
_slashslash = true;
abbrAxis = root.abbrAxis;
result = qyInput;
}
break;
}
break;
case Axis.AxisType.Preceding:
result = new PrecedingQuery(
qyInput,
root.Name,
root.Prefix,
URN,
root.Type);
_specialAxis = hasReverseAxis = true;
break;
case Axis.AxisType.Following :
result = new FollowingQuery(
qyInput,
root.Name,
root.Prefix,
URN,
root.Type);
_specialAxis = true;
break;
case Axis.AxisType.FollowingSibling :
result = new FollSiblingQuery(
qyInput,
root.Name,
root.Prefix,
URN,
root.Type);
if (_specialAxis || (qyInput != null && (int)qyInput.getName() > (int) Querytype.Self)) {
result = new DocumentOrderQuery(result);
}
break;
case Axis.AxisType.PrecedingSibling :
result = new PreSiblingQuery(
qyInput,
root.Name,
root.Prefix,
URN,
root.Type);
hasReverseAxis = true;
break;
case Axis.AxisType.Attribute:
result = new AttributeQuery(
qyInput,
root.Name,
root.Prefix,
URN,
root.Type);
break;
case Axis.AxisType.Self:
result = new XPathSelfQuery(
qyInput,
root.Name,
root.Prefix,
URN,
root.Type);
break;
case Axis.AxisType.Namespace:
if (
(root.Type == XPathNodeType.All || root.Type == XPathNodeType.Element || root.Type == XPathNodeType.Attribute) &&
root.Prefix == string.Empty
) {
result = new NamespaceQuery(qyInput, root.Name, root.Prefix, URN, root.Type);
}
else {
result = new EmptyNamespaceQuery();
}
break;
default:
throw new XPathException(Res.Xp_NotSupported, _query);
}
return result;
}
