Examples with FunctionIterator com.sri.ai.util.collect.FunctionIterator used on opensource projects

Example 1 with FunctionIterator

use of com.sri.ai.util.collect.FunctionIterator in project aic-expresso by aic-sri-international.

the class AbstractSingleVariableNumericConstraintFeasibilityRegionStepSolver method makeUpperBoundsAndStrictness.

/** 
	 * A method setting {@link #upperBoundsIncludingImplicitOnes} and {@link #fromUpperBoundsIncludingImplicitOnesToStrictness}
	 * from constraint and variable's type.
	 * @param context
	 */
protected void makeUpperBoundsAndStrictness(Context context) {
    AbstractSingleVariableConstraint abstractSingleVariableConstraint = (AbstractSingleVariableConstraint) constraint;
    FunctionIterator<Expression, Pair<Expression, Boolean>> upperBoundsFromPositiveNormalizedAtomsIterator = functionIterator(predicateIterator(abstractSingleVariableConstraint.getPositiveNormalizedAtoms(), e -> e.hasFunctor(LESS_THAN)), // strict
    e -> processExplicitUpperBoundAndStrictnessPair(e.get(1), true, context));
    FunctionIterator<Expression, Pair<Expression, Boolean>> upperBoundsFromNegativeNormalizedAtomsIterator = functionIterator(predicateIterator(abstractSingleVariableConstraint.getNegativeNormalizedAtoms(), // not (X > Y) <=> X <= Y, so Y is a non-strict upper bound
    e -> e.hasFunctor(GREATER_THAN)), // non-strict
    e -> processExplicitUpperBoundAndStrictnessPair(e.get(1), false, context));
    Pair<Expression, Boolean> typeUpperBound = getTypeUpperBoundAndStrictness(context);
    Iterator<Pair<Expression, Boolean>> upperBoundsAndStrictnessIterator = new NestedIterator<>(upperBoundsFromPositiveNormalizedAtomsIterator, upperBoundsFromNegativeNormalizedAtomsIterator, typeUpperBound);
    upperBoundsIncludingImplicitOnes = arrayList();
    fromUpperBoundsIncludingImplicitOnesToStrictness = map();
    for (Pair<Expression, Boolean> boundAndStrictness : in(upperBoundsAndStrictnessIterator)) {
        Expression bound = boundAndStrictness.first;
        upperBoundsIncludingImplicitOnes.add(bound);
        Boolean strictness = boundAndStrictness.second;
        Boolean previousStrictness = fromUpperBoundsIncludingImplicitOnesToStrictness.get(bound);
        if (previousStrictness == null || (!previousStrictness && strictness)) {
            // if no strictness information so far, store current one; otherwise, only need to change it if previous occurrences were non-strict and this one is strict
            fromUpperBoundsIncludingImplicitOnesToStrictness.put(bound, strictness);
        }
    }
}

Example 2 with FunctionIterator

use of com.sri.ai.util.collect.FunctionIterator in project aic-expresso by aic-sri-international.

the class SatisfiabilityOfSingleVariableEqualityConstraintStepSolver method getPropagatedCNFBesidesPropagatedLiterals.

@Override
protected Iterable<Iterable<Expression>> getPropagatedCNFBesidesPropagatedLiterals(Context context) {
    if (!variableIsBoundToUniquelyNamedConstant(context)) {
        // the following logic only holds if the variable is not bound to a uniquely named constants,
        // since that eliminates all disequalities to other uniquely named constants as redundant
        long variableDomainSize = getConstraint().getVariableTypeSize(context);
        if (variableDomainSize >= 0 && getConstraint().numberOfDisequals() >= variableDomainSize) {
            // the following procedure can be very expensive but the condition above will rarely be satisfied
            ArrayList<Expression> variableDisequals = getVariableDisequals(context);
            Set<Expression> uniquelyNamedConstantDisequals = getUniquelyNamedConstantDisequals(context);
            Expression typeExpression = GrinderUtil.getTypeExpression(getConstraint().getVariable(), context);
            Type type = context.getType(typeExpression);
            ArrayList<Expression> remainingUniquelyNamedConstants = arrayListFrom(new PredicateIterator<>(type.iterator(), c -> !uniquelyNamedConstantDisequals.contains(c)));
            CartesianProductIterator<ArrayList<Expression>> subsetOfVariableDisequalsAndRemainingConstantsPermutationIterator = new CartesianProductIterator<ArrayList<Expression>>(() -> new SubsetsOfKIterator<Expression>(variableDisequals, remainingUniquelyNamedConstants.size()), () -> new PermutationIterator<Expression>(remainingUniquelyNamedConstants));
            FunctionIterator<ArrayList<ArrayList<Expression>>, Iterable<Expression>> clausesIterator = FunctionIterator.make(subsetOfVariableDisequalsAndRemainingConstantsPermutationIterator, (ArrayList<ArrayList<Expression>> subsetAndPermutation) -> clauseNegatingAssignmentOfSubsetOfVariablesToParticularPermutationOfRemainingConstants(subsetAndPermutation));
            Iterable<Iterable<Expression>> clauses = in(clausesIterator);
            return clauses;
        }
    }
    // otherwise, nothing is implied.
    return list();
}

Example 3 with FunctionIterator

use of com.sri.ai.util.collect.FunctionIterator in project aic-expresso by aic-sri-international.

the class DefaultCompoundSyntaxTree method toStringWithoutCaching.

@Override
public String toStringWithoutCaching() {
    String rootTreeString = getRootTree().toString();
    if (!(getRootTree() instanceof SyntaxLeaf)) {
        rootTreeString = "(" + rootTreeString + ")";
    }
    Iterator stringOfSubTrees = new FunctionIterator<SyntaxTree, String>(new ToStringWithoutCaching(), getImmediateSubTrees());
    return rootTreeString + "(" + Util.join(", ", stringOfSubTrees) + ")";
}

Example 4 with FunctionIterator

use of com.sri.ai.util.collect.FunctionIterator in project aic-expresso by aic-sri-international.

the class AbstractSingleVariableNumericConstraintFeasibilityRegionStepSolver method getDisequals.

protected ArrayList<Expression> getDisequals() {
    if (disequals == null) {
        AbstractSingleVariableConstraint abstractSingleVariableConstraint = (AbstractSingleVariableConstraint) constraint;
        Iterator<Expression> disequalsIterator = functionIterator(predicateIterator(abstractSingleVariableConstraint.getNegativeNormalizedAtoms(), // negative equality is disequality
        e -> e.hasFunctor(FunctorConstants.EQUALITY)), e -> e.get(1));
        disequals = arrayListFrom(disequalsIterator);
    }
    return disequals;
}

Example 5 with FunctionIterator

use of com.sri.ai.util.collect.FunctionIterator in project aic-expresso by aic-sri-international.

the class AbstractSingleVariableNumericConstraintFeasibilityRegionStepSolver method getEquals.

protected ArrayList<Expression> getEquals() {
    if (equals == null) {
        AbstractSingleVariableConstraint abstractSingleVariableConstraint = (AbstractSingleVariableConstraint) constraint;
        Iterator<Expression> equalsIterator = functionIterator(predicateIterator(abstractSingleVariableConstraint.getPositiveNormalizedAtoms(), e -> e.hasFunctor(EQUALITY)), e -> e.get(1));
        equals = arrayListFrom(equalsIterator);
    }
    return equals;
}