001/*
002 * Copyright 2010-2013 JetBrains s.r.o.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.jetbrains.k2js.translate.intrinsic.operation;
018
019import com.google.dart.compiler.backend.js.ast.JsBinaryOperation;
020import com.google.dart.compiler.backend.js.ast.JsBinaryOperator;
021import com.google.dart.compiler.backend.js.ast.JsExpression;
022import com.google.dart.compiler.backend.js.ast.JsLiteral;
023import org.jetbrains.annotations.NotNull;
024import org.jetbrains.jet.lang.descriptors.FunctionDescriptor;
025import org.jetbrains.jet.lang.psi.JetBinaryExpression;
026import org.jetbrains.jet.lang.psi.JetExpression;
027import org.jetbrains.jet.lang.resolve.name.Name;
028import org.jetbrains.jet.lang.types.expressions.OperatorConventions;
029import org.jetbrains.jet.lexer.JetTokens;
030import org.jetbrains.k2js.translate.context.TranslationContext;
031import org.jetbrains.k2js.translate.intrinsic.functions.factories.TopLevelFIF;
032import org.jetbrains.k2js.translate.intrinsic.functions.patterns.NamePredicate;
033import org.jetbrains.k2js.translate.utils.JsAstUtils;
034import org.jetbrains.k2js.translate.utils.JsDescriptorUtils;
035import org.jetbrains.k2js.translate.utils.TranslationUtils;
036
037import java.util.Arrays;
038
039import static org.jetbrains.k2js.translate.utils.BindingUtils.getFunctionDescriptorForOperationExpression;
040import static org.jetbrains.k2js.translate.utils.PsiUtils.getOperationToken;
041
042public final class EqualsIntrinsic implements BinaryOperationIntrinsic {
043
044    @Override
045    public boolean isApplicable(@NotNull JetBinaryExpression expression, @NotNull TranslationContext context) {
046        if (!OperatorConventions.EQUALS_OPERATIONS.contains(getOperationToken(expression))) {
047            return false;
048        }
049        FunctionDescriptor functionDescriptor = getFunctionDescriptorForOperationExpression(context.bindingContext(), expression);
050        assert functionDescriptor != null;
051        return JsDescriptorUtils.isStandardDeclaration(functionDescriptor);
052    }
053
054    @Override
055    @NotNull
056    public JsExpression apply(@NotNull JetBinaryExpression expression,
057            @NotNull JsExpression left,
058            @NotNull JsExpression right,
059            @NotNull TranslationContext context) {
060        boolean isNegated = getOperationToken(expression).equals(JetTokens.EXCLEQ);
061        if (right == JsLiteral.NULL || left == JsLiteral.NULL) {
062            return TranslationUtils.nullCheck(right == JsLiteral.NULL ? left : right, isNegated);
063        }
064        else if (canUseSimpleEquals(expression, context)) {
065            return new JsBinaryOperation(isNegated ? JsBinaryOperator.REF_NEQ : JsBinaryOperator.REF_EQ, left, right);
066        }
067
068        JsExpression result = TopLevelFIF.EQUALS.apply(left, Arrays.asList(right), context);
069        return isNegated ? JsAstUtils.negated(result) : result;
070    }
071
072    private static boolean canUseSimpleEquals(@NotNull JetBinaryExpression expression, @NotNull TranslationContext context) {
073        JetExpression left = expression.getLeft();
074        assert left != null : "No left-hand side: " + expression.getText();
075        Name typeName = JsDescriptorUtils.getNameIfStandardType(left, context);
076        return typeName != null && NamePredicate.PRIMITIVE_NUMBERS.apply(typeName);
077    }
078}