santiagopg 2002/09/17 07:20:59
Modified: java/src/org/apache/xalan/xsltc/compiler xpath.cup
Log:
Additional optimizations in expansion of '//'.
Revision Changes Path
1.43 +45 -10
xml-xalan/java/src/org/apache/xalan/xsltc/compiler/xpath.cup
Index: xpath.cup
===================================================================
RCS file:
/home/cvs/xml-xalan/java/src/org/apache/xalan/xsltc/compiler/xpath.cup,v
retrieving revision 1.42
retrieving revision 1.43
diff -u -r1.42 -r1.43
--- xpath.cup 16 Sep 2002 19:40:28 -0000 1.42
+++ xpath.cup 17 Sep 2002 14:20:59 -0000 1.43
@@ -70,6 +70,7 @@
import java.io.StringReader;
import java_cup.runtime.*;
+import org.apache.xalan.xsltc.DOM;
import org.apache.xalan.xsltc.dom.Axis;
import org.apache.xalan.xsltc.runtime.Operators;
import org.apache.xalan.xsltc.compiler.util.ErrorMsg;
@@ -229,6 +230,16 @@
return rlp;
}
}
+
+ /**
+ * Returns true if the axis applies to elements only. The axes
+ * child, attribute, namespace, descendant result in non-empty
+ * nodesets only if the context node is of type element.
+ */
+ public boolean isElementAxis(int axis) {
+ return (axis == Axis.CHILD || axis == Axis.ATTRIBUTE ||
+ axis == Axis.NAMESPACE || axis == Axis.DESCENDANT);
+ }
:}
terminal SLASH, DOT, LBRACK, RBRACK, VBAR, LPAREN, RPAREN, STAR, COMMA;
@@ -513,12 +524,22 @@
| FilterExpr:fexp DSLASH RelativeLocationPath:rlp
{:
- // Expand '//' into '/descendant-or-self::node()/'
- Step step = new Step(Axis.DESCENDANTORSELF, NodeTest.ANODE, null);
+ //
+ // Expand '//' into '/descendant-or-self::node()/' or
+ // into /descendant-or-self::*/
+ //
+ int nodeType = DOM.NO_TYPE;
+ if (rlp instanceof Step &&
+ parser.isElementAxis(((Step) rlp).getAxis()))
+ {
+ nodeType = DOM.ELEMENT;
+ }
+ final Step step = new Step(Axis.DESCENDANTORSELF, nodeType, null);
FilterParentPath fpp = new FilterParentPath(fexp, step);
fpp = new FilterParentPath(fpp, rlp);
- if (!(fexp instanceof KeyCall))
+ if (fexp instanceof KeyCall == false) {
fpp.setDescendantAxis();
+ }
RESULT = fpp;
:};
@@ -580,13 +601,15 @@
else {
// Expand './/step' -> 'descendant-or-self::*/step'
if (rlp instanceof Step &&
((Step)rlp).isAbbreviatedDot()) {
- Step left = new Step(Axis.DESCENDANTORSELF, -1, null);
+ Step left = new Step(Axis.DESCENDANTORSELF,
+ DOM.ELEMENT, null);
RESULT = new ParentLocationPath(left, right);
}
else {
// Expand 'rlp//step' ->
'rlp/descendant-or-self::*/step'
RelativeLocationPath left = (RelativeLocationPath)rlp;
- Step mid = new Step(Axis.DESCENDANTORSELF, -1, null);
+ Step mid = new Step(Axis.DESCENDANTORSELF,
+ DOM.ELEMENT, null);
ParentLocationPath ppl = new ParentLocationPath(mid,
right);
RESULT = new ParentLocationPath(left, ppl);
}
@@ -595,14 +618,16 @@
else if ((axis == Axis.ATTRIBUTE) || (type ==
NodeTest.ATTRIBUTE)) {
// Expand 'rlp//step' -> 'rlp/descendant-or-self::*/step'
RelativeLocationPath left = (RelativeLocationPath)rlp;
- Step middle = new Step(Axis.DESCENDANTORSELF, -1, null);
+ Step middle = new Step(Axis.DESCENDANTORSELF,
+ DOM.ELEMENT, null);
ParentLocationPath ppl = new ParentLocationPath(middle,
right);
RESULT = new ParentLocationPath(left, ppl);
}
else {
// Expand 'rlp//step' -> 'rlp/descendant-or-self::node()/step'
RelativeLocationPath left = (RelativeLocationPath)rlp;
- Step middle = new Step(Axis.DESCENDANTORSELF, -1, null);
+ Step middle = new Step(Axis.DESCENDANTORSELF,
+ DOM.NO_TYPE, null);
ParentLocationPath ppl = new ParentLocationPath(middle,
right);
RESULT = new ParentLocationPath(left, ppl);
}
@@ -611,8 +636,18 @@
AbbreviatedAbsoluteLocationPath ::= DSLASH RelativeLocationPath:rlp
{:
- final Step step = new Step(Axis.DESCENDANTORSELF, -1, null);
- RESULT = new AbsoluteLocationPath(parser.insertStep(step,
+ //
+ // Expand '//' into '/descendant-or-self::node()/' or
+ // into /descendant-or-self::*/
+ //
+ int nodeType = DOM.NO_TYPE;
+ if (rlp instanceof Step &&
+ parser.isElementAxis(((Step) rlp).getAxis()))
+ {
+ nodeType = DOM.ELEMENT;
+ }
+ final Step step = new Step(Axis.DESCENDANTORSELF, nodeType, null);
+ RESULT = new AbsoluteLocationPath(parser.insertStep(step,
(RelativeLocationPath) rlp));
:};
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