Class SimpleSolutionManager

java.lang.Object

fr.inria.rules.integraal.query_evaluation.conjunction.backtrack.SimpleSolutionManager

All Implemented Interfaces:

SolutionManager

public final class SimpleSolutionManager
extends Object
implements SolutionManager

SimpleSolutionManager

Lean, allocation‑friendly implementation of SolutionManager.

Key points:

• In‑place fusion via mergeInPlace – zero temporary objects on the hot path.
• For each depth we keep only: the candidate spliterator and truly new variables (those not bound at any shallower level) so rollback work is minimal.
• A global boundVariables set tracks which variables are already present to compute the fresh set in O(n).

Author:

Guillaume Perution-Kihli

Constructor Summary

Constructors

Constructor	Description
SimpleSolutionManager()	Creates a solution manager with an empty initial substitution.
SimpleSolutionManager(Substitution prefix)	Creates a solution manager with the supplied initial substitution.

Method Summary

Modifier and Type	Method	Description
void	add(int level, Spliterator<Substitution> substitutions, Collection<Variable> newVariables)	Register the spliterator that will supply substitutions for level together with the list of variables that those substitutions can bind for the first time.
Substitution	copyCurrentSolution()	Returns a stable snapshot of the current solution.
SolutionManager	deepCopy()	Creates an independent copy of this solution manager.
Substitution	getCurrentSolution()	Returns the substitution that is currently valid at all explored levels.
Spliterator<Substitution>	getSpliterator(int level)	Returns the spliterator registered for a level.
boolean	next(int level)	Advance the iterator at level so the next candidate substitution (if any) is merged into the global solution.
void	pruneOtherIterators(int level)	Prunes every stored iterator except the selected level.
void	replaceSpliterator(int level, Spliterator<Substitution> newSpliterator)	Replaces the spliterator registered for a level.
String	toString()

Methods inherited from class Object

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

Constructor Details

SimpleSolutionManager

public SimpleSolutionManager()

Creates a solution manager with an empty initial substitution.

SimpleSolutionManager

public SimpleSolutionManager(Substitution prefix)

Creates a solution manager with the supplied initial substitution.

Parameters:

prefix - the substitution that must always remain in the current solution

Method Details

getCurrentSolution

public Substitution getCurrentSolution()

Description copied from interface: SolutionManager

Returns the substitution that is currently valid at all explored levels.

Live view: subsequent calls to SolutionManager.next(int) may mutate and/or invalidate the content. Clone it with SolutionManager.copyCurrentSolution() if you need to keep a stable version.

Specified by:

getCurrentSolution in interface SolutionManager

Returns:

the current live substitution

copyCurrentSolution

public Substitution copyCurrentSolution()

Description copied from interface: SolutionManager

Returns a stable snapshot of the current solution.

Specified by:

copyCurrentSolution in interface SolutionManager

Returns:

a defensive copy of the current solution (safe to keep).

next

public boolean next(int level)

Description copied from interface: SolutionManager

Advance the iterator at level so the next candidate substitution (if any) is merged into the global solution.

Specified by:

next in interface SolutionManager

Parameters:

level - depth in the search tree (0‑based)

Returns:

true if a compatible substitution exists, false otherwise.

add

public void add(int level,
 Spliterator<Substitution> substitutions,
 Collection<Variable> newVariables)

Description copied from interface: SolutionManager

Register the spliterator that will supply substitutions for level together with the
list of variables that those substitutions can bind for the first time.

Specified by:

add in interface SolutionManager

Parameters:

level - depth in the search tree (0-based)

substitutions - the substitutions available at that level

newVariables - the variables that may become bound at that level

getSpliterator

public Spliterator<Substitution> getSpliterator(int level)

Description copied from interface: SolutionManager

Returns the spliterator registered for a level.

Specified by:

getSpliterator in interface SolutionManager

Parameters:

level - depth in the search tree (0-based)

Returns:

the spliterator associated with level, or null.

replaceSpliterator

public void replaceSpliterator(int level,
 Spliterator<Substitution> newSpliterator)

Description copied from interface: SolutionManager

Replaces the spliterator registered for a level. Replace the spliterator stored for level.

Specified by:

replaceSpliterator in interface SolutionManager

Parameters:

level - depth in the search tree (0-based)

newSpliterator - the replacement spliterator

pruneOtherIterators

public void pruneOtherIterators(int level)

Description copied from interface: SolutionManager

Prunes every stored iterator except the selected level. Remove (or empty) every level that is not equal to level.

Specified by:

pruneOtherIterators in interface SolutionManager

Parameters:

level - the level to keep

deepCopy

public SolutionManager deepCopy()

Description copied from interface: SolutionManager

Creates an independent copy of this solution manager.

Specified by:

deepCopy in interface SolutionManager

Returns:

an independent copy of this manager so that another branch can evolve in parallel without interference.

toString

public String toString()

Overrides:

toString in class Object