[GitHub] jena issue #345: JENA-1468: Retain variables in op (table)
Github user afs commented on the issue: https://github.com/apache/jena/pull/345 Use new operation `TableEmpty.isTableEmpty` to test whether a data structure is the empty table, not rely on the contents. Thus a table of no rows but with declared variables, keeps the variables in the algebra. ---
[GitHub] jena issue #345: JENA-1468: Retain variables in op (table)
Github user rvesse commented on the issue: https://github.com/apache/jena/pull/345 Does https://github.com/apache/jena/blob/cc038809fb622779933831011909714e22ef494c/jena-arq/src/main/java/org/apache/jena/sparql/algebra/optimize/TransformPromoteTableEmpty.java#L160 need to change to use the new test? ---
[GitHub] jena issue #345: JENA-1468: Retain variables in op (table)
Github user afs commented on the issue:
https://github.com/apache/jena/pull/345
It does not need to change. It will behave as before.
The changes here differentiate between a table that is of class
`TableEmpty`, using function `TableEmpty.isTableEmpty`, and a table that
evaluates to empty (no rows) using method `Table.isEmpty`. Previously, there
was only the latter method.
`VALUES ?foo {}` creates algebra `TableN` with declared variable `?foo` and
no rows. It printed (incorrectly) as `(table empty)` but internally it was a
`TableN` and method `isEmpty` is true (no rows).
Now it prints as `(table (vars ?foo))`. There is no change to the data
structure in the algebra.
The difference is on conversion to a string, and on `.equals`, then only if
read in again because it was not round-tripping the data structure, even if it
evaluated to the same thing. Declared variables make no difference to the value
of a table and that follows the SPARQL 1.1 spec exactly.
As it makes no eval difference, we haven't noticed before.
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[GitHub] jena issue #345: JENA-1468: Retain variables in op (table)
Github user RickMoynihan commented on the issue: https://github.com/apache/jena/pull/345 @afs This is fantastic thank you so much! I've checked out the branch from your repo, built a local version and can confirm it fixes the issue for us. Do you have any idea when this will be merged and a `3.7.0` release of JENA released? ---
[GitHub] jena issue #345: JENA-1468: Retain variables in op (table)
Github user afs commented on the issue: https://github.com/apache/jena/pull/345 @RickMoynihan : thanks for looking at it. Merge : soon, because you provide independent checking. It will then be in the daily development build but that is not a formal release. Release : this depends on people-time, and realistically, we can't make solid timelines. We do run "releasable master" means that the master branch is releasable most of the time so the dev builds are realistic. The general project hope is every 3-4 months, though we had an out-of-step release at 3.6.0. That is not a commitment though! ---
[GitHub] jena issue #345: JENA-1468: Retain variables in op (table)
Github user RickMoynihan commented on the issue: https://github.com/apache/jena/pull/345 Thanks for the info @afs, was really just checking incase there was a release planned in the next week or so. Looks like I'll be deploying an internal build to our private artifact bucket then :-) ---
[GitHub] jena issue #345: JENA-1468: Retain variables in op (table)
Github user rvesse commented on the issue: https://github.com/apache/jena/pull/345 @afs Thanks for the more detailed explanation +1 to merge ---
