org.sonar.javascript.se.ProgramState.java Source code

Introduction

Here is the source code for org.sonar.javascript.se.ProgramState.java

Source

/*
 * SonarQube JavaScript Plugin
 * Copyright (C) 2011-2016 SonarSource SA
 * mailto:contact AT sonarsource DOT com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
package org.sonar.javascript.se;

import com.google.common.collect.ImmutableMap;
import java.util.Map.Entry;
import org.sonar.plugins.javascript.api.symbols.Symbol;

public class ProgramState {

    private final ImmutableMap<Symbol, SymbolicValue> valuesBySymbol;

    private static final ProgramState EMPTY = new ProgramState(ImmutableMap.<Symbol, SymbolicValue>of());

    public static ProgramState emptyState() {
        return EMPTY;
    }

    private ProgramState(ImmutableMap<Symbol, SymbolicValue> valuesBySymbol) {
        this.valuesBySymbol = valuesBySymbol;
    }

    public ProgramState copyAndAddValue(Symbol symbol, SymbolicValue value) {
        ImmutableMap.Builder<Symbol, SymbolicValue> builder = ImmutableMap.<Symbol, SymbolicValue>builder();
        for (Entry<Symbol, SymbolicValue> entry : valuesBySymbol.entrySet()) {
            if (!entry.getKey().equals(symbol)) {
                builder.put(entry.getKey(), entry.getValue());
            }
        }
        builder.put(symbol, value);
        return new ProgramState(builder.build());
    }

    public SymbolicValue get(Symbol symbol) {
        return valuesBySymbol.get(symbol);
    }

    public ProgramState constrain(Symbol symbol, Truthiness truthiness) {
        SymbolicValue value = get(symbol);
        if (value == null) {
            return this;
        }
        return copyAndAddValue(symbol, value.constrain(truthiness));
    }

    @Override
    public int hashCode() {
        return valuesBySymbol.hashCode();
    }

    @Override
    public boolean equals(Object obj) {
        if (obj == null || getClass() != obj.getClass()) {
            return false;
        }
        ProgramState other = (ProgramState) obj;
        return this.valuesBySymbol.equals(other.valuesBySymbol);
    }

}