Bug #2882
closed
QuickCompare for numerics fails if whitespace is present
Category:
XPath conformance
Applies to branch:
9.7, trunk
Fix Committed on Branch:
9.7, trunk
Fixed in Maintenance Release:
Description
Reported by Wolfgang May on the saxon-help list at SourceForge:
I have an XML case where numeric values are not always perfectly formatted.
As far as I understand, numeric comparisons in XPath filters should nevertheless
work - but they don't (saxon 9.7.0.7).
Small Example:
let $ex :=
<bla><n>10</n>
<n>123</n>
<n> 1234 </n>
<n>
1234
</n>
<n>12345</n>
</bla>
return
$ex[n>1000]
- Status changed from New to In Progress
- Applies to branch 9.8 added
- Fix Committed on Branch 9.7, 9.8 added
I have committed a fix on the 9.7 and 9.8 branches that fixes the problem.
The strategy being used is to avoid converting the string to a number if possible. Assuming positive numbers without leading zeroes:
(a) if the numbers are unequal lengths then the shorter one is smaller
(b) if the first digit differs then this determines the comparison
If the numbers are the same length and share the same first digit, then the code reverts to the "slow path" of converting the string to a number; and if there is no decimal point then this fails in the event that the string contains spaces.
While looking at this I noticed that the quick-compare code is used for generalComparisons but not for valueComparisons, which is unfortunate since many generalComparisons are optimized into a valueComparison. So I'll leave the bug open as a reminder to take a look at this.
- Status changed from In Progress to Resolved
On the 9.8 branch I have made further changes so that the quickCompare optimization is now used for ValueComparisons as well as GeneralComparisons, if sufficient type information is available statically to determine that this is appropriate.
- % Done changed from 0 to 100
Bug fix applied in the Saxon 9.7.0.8 maintenance release.
- Status changed from Resolved to Closed
- Fixed in Maintenance Release 9.7.0.8 added
- Applies to branch trunk added
- Applies to branch deleted (
9.8)
- Fix Committed on Branch trunk added
- Fix Committed on Branch deleted (
9.8)
Please register to edit this issue
Also available in: Atom
PDF
.