diff options
Diffstat (limited to 'javaparser-symbol-solver-core/src/main/java/com/github/javaparser/symbolsolver/resolution/typeinference/ConstraintFormulaSet.java')
-rw-r--r-- | javaparser-symbol-solver-core/src/main/java/com/github/javaparser/symbolsolver/resolution/typeinference/ConstraintFormulaSet.java | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/javaparser-symbol-solver-core/src/main/java/com/github/javaparser/symbolsolver/resolution/typeinference/ConstraintFormulaSet.java b/javaparser-symbol-solver-core/src/main/java/com/github/javaparser/symbolsolver/resolution/typeinference/ConstraintFormulaSet.java new file mode 100644 index 000000000..bca6e12e4 --- /dev/null +++ b/javaparser-symbol-solver-core/src/main/java/com/github/javaparser/symbolsolver/resolution/typeinference/ConstraintFormulaSet.java @@ -0,0 +1,53 @@ +package com.github.javaparser.symbolsolver.resolution.typeinference; + +import com.github.javaparser.symbolsolver.model.resolution.TypeSolver; + +import java.util.LinkedList; +import java.util.List; + +/** + * @author Federico Tomassetti + */ +public class ConstraintFormulaSet { + private List<ConstraintFormula> constraintFormulas; + + public ConstraintFormulaSet withConstraint(ConstraintFormula constraintFormula) { + ConstraintFormulaSet newInstance = new ConstraintFormulaSet(); + newInstance.constraintFormulas.addAll(this.constraintFormulas); + newInstance.constraintFormulas.add(constraintFormula); + return newInstance; + } + + private static final ConstraintFormulaSet EMPTY = new ConstraintFormulaSet(); + + public static ConstraintFormulaSet empty() { + return EMPTY; + } + + private ConstraintFormulaSet() { + constraintFormulas = new LinkedList<>(); + } + + /** + * Takes a compatibility assertion about an expression or type, called a constraint formula, and reduces it to a + * set of bounds on inference variables. Often, a constraint formula reduces to other constraint formulas, + * which must be recursively reduced. A procedure is followed to identify these additional constraint formulas and, + * ultimately, to express via a bound set the conditions under which the choices for inferred types would render + * each constraint formula true. + */ + public BoundSet reduce(TypeSolver typeSolver) { + List<ConstraintFormula> constraints = new LinkedList<>(constraintFormulas); + BoundSet boundSet = BoundSet.empty(); + while (constraints.size() > 0) { + ConstraintFormula constraintFormula = constraints.remove(0); + ConstraintFormula.ReductionResult reductionResult = constraintFormula.reduce(boundSet); + constraints.addAll(reductionResult.getConstraintFormulas()); + boundSet.incorporate(reductionResult.getBoundSet(), typeSolver); + } + return boundSet; + } + + public boolean isEmpty() { + return constraintFormulas.isEmpty(); + } +} |