Class FusePathPlusTailAlternationUnionTransform

java.lang.Object

org.eclipse.rdf4j.queryrender.sparql.ir.util.transform.BaseTransform

org.eclipse.rdf4j.queryrender.sparql.ir.util.transform.FusePathPlusTailAlternationUnionTransform

public class FusePathPlusTailAlternationUnionTransform
extends BaseTransform

Fuse a path triple followed by a UNION of two single-step tail triples into a single path with an alternation tail. Shape: - Input: PT: ?s P ?mid . UNION of two branches that each connect ?mid to the same end variable via constant predicates in opposite directions (forward/inverse), optionally GRAPH-wrapped with the same graph ref. - Output: ?s P/(p|^p) ?end . Notes: - Does not fuse across UNIONs marked as new scope (explicit user UNIONs). - Requires the bridge variable (?mid) to be an _anon_path_* var so we never eliminate user-visible vars.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	FusePathPlusTailAlternationUnionTransform.BranchTriple
static final class	FusePathPlusTailAlternationUnionTransform.TripleJoin

Field Summary

Fields inherited from class BaseTransform

ANON_PATH_INVERSE_PREFIX, ANON_PATH_PREFIX

Method Summary

Modifier and Type	Method	Description
static IrBGP	apply(IrBGP bgp, TupleExprIRRenderer r)
static FusePathPlusTailAlternationUnionTransform.TripleJoin	classifyTailJoin(FusePathPlusTailAlternationUnionTransform.BranchTriple bt, Var midVar, TupleExprIRRenderer r)
static boolean	compatibleGraphs(Var a, Var b)
static FusePathPlusTailAlternationUnionTransform.BranchTriple	getSingleBranchSp(IrBGP branch)

Methods inherited from class BaseTransform

bgpWithLines, branchHasAnonPathBridge, copyAllExcept, fuseAdjacentPtThenPt, fuseAdjacentSpThenPt, fuseAltInverseTailBGP, fusePtSpPtSequence, invertNegatedPropertySet, iri, isAnonPathInverseVar, isAnonPathVar, isConstantIriPredicate, joinPathWithLaterSp, mergeNpsMembers, normalizeCompactNps, orientBareNpsForNext, rewriteContainers, sameVar, sameVarOrValue, unionBranchesAllHaveAnonPathBridge, unionBranchesShareAnonPathVarWithAllowedRoleMapping, unionBranchesShareCommonAnonPathVarName, unionIsExplicitAndAllBranchesScoped, varOrValue

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

apply

public static IrBGP apply(IrBGP bgp,
 TupleExprIRRenderer r)

compatibleGraphs

public static boolean compatibleGraphs(Var a,
 Var b)

classifyTailJoin

public static FusePathPlusTailAlternationUnionTransform.TripleJoin classifyTailJoin(FusePathPlusTailAlternationUnionTransform.BranchTriple bt,
 Var midVar,
 TupleExprIRRenderer r)

getSingleBranchSp

public static FusePathPlusTailAlternationUnionTransform.BranchTriple getSingleBranchSp(IrBGP branch)