| /******************************************************************************* |
| * Copyright (c) 2013, 2015 GK Software AG. |
| * |
| * This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License 2.0 |
| * which accompanies this distribution, and is available at |
| * https://www.eclipse.org/legal/epl-2.0/ |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| * Contributors: |
| * Stephan Herrmann - initial API and implementation |
| * Lars Vogel <Lars.Vogel@vogella.com> - Contributions for |
| * Bug 473178 |
| *******************************************************************************/ |
| package org.eclipse.jdt.internal.compiler.lookup; |
| |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.LinkedHashSet; |
| import java.util.List; |
| import java.util.Set; |
| |
| /** |
| * Implementation of 18.1.2 in JLS8 |
| */ |
| abstract class ConstraintFormula extends ReductionResult { |
| |
| static final List<InferenceVariable> EMPTY_VARIABLE_LIST = Collections.emptyList(); |
| static final ConstraintFormula[] NO_CONSTRAINTS = new ConstraintTypeFormula[0]; |
| |
| // constants for unicode debug output from ASCII source files: |
| static final char LEFT_ANGLE_BRACKET = '\u27E8'; |
| static final char RIGHT_ANGLE_BRACKET = '\u27E9'; |
| |
| public abstract Object reduce(InferenceContext18 inferenceContext) throws InferenceFailureException; |
| |
| Collection<InferenceVariable> inputVariables(InferenceContext18 context) { |
| return EMPTY_VARIABLE_LIST; |
| } |
| |
| Collection<InferenceVariable> outputVariables(InferenceContext18 context) { |
| Set<InferenceVariable> variables = new LinkedHashSet<>(); |
| this.right.collectInferenceVariables(variables); |
| if (!variables.isEmpty()) |
| variables.removeAll(inputVariables(context)); |
| return variables; |
| } |
| |
| public boolean applySubstitution(BoundSet solutionSet, InferenceVariable[] variables) { |
| for (int i=0; i<variables.length; i++) { |
| InferenceVariable variable = variables[i]; |
| TypeBinding instantiation = solutionSet.getInstantiation(variables[i], null); |
| if (instantiation == null) |
| return false; |
| this.right = this.right.substituteInferenceVariable(variable, instantiation); |
| } |
| return true; |
| } |
| |
| // for debug toString(): |
| protected void appendTypeName(StringBuffer buf, TypeBinding type) { |
| if (type instanceof CaptureBinding18) |
| buf.append(type.toString()); // contains more info than readable name |
| else |
| buf.append(type.readableName()); |
| } |
| } |