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.context;
018
019import com.google.dart.compiler.backend.js.ast.*;
020import com.intellij.openapi.util.Pair;
021import org.jetbrains.annotations.NotNull;
022import org.jetbrains.annotations.Nullable;
023
024import static com.google.dart.compiler.backend.js.ast.JsVars.JsVar;
025
026//TODO: consider renaming to scoping context
027public final class DynamicContext {
028    @NotNull
029    public static DynamicContext rootContext(@NotNull JsScope rootScope, @NotNull JsBlock globalBlock) {
030        return new DynamicContext(rootScope, globalBlock);
031    }
032
033    @NotNull
034    public static DynamicContext newContext(@NotNull JsScope scope, @NotNull JsBlock block) {
035        return new DynamicContext(scope, block);
036    }
037
038    @NotNull
039    private final JsScope currentScope;
040
041    @NotNull
042    private final JsBlock currentBlock;
043
044    @Nullable
045    private JsVars vars;
046
047    private DynamicContext(@NotNull JsScope scope, @NotNull JsBlock block) {
048        this.currentScope = scope;
049        this.currentBlock = block;
050    }
051
052    @NotNull
053    public DynamicContext innerBlock(@NotNull JsBlock block) {
054        return new DynamicContext(currentScope, block);
055    }
056
057    @NotNull
058    public TemporaryVariable declareTemporary(@Nullable JsExpression initExpression) {
059        if (vars == null) {
060            vars = new JsVars();
061            currentBlock.getStatements().add(vars);
062        }
063
064        JsName temporaryName = currentScope.declareTemporary();
065        vars.add(new JsVar(temporaryName, null));
066        return TemporaryVariable.create(temporaryName, initExpression);
067    }
068
069    //TODO: replace return type to make it more readable
070    @NotNull
071    public Pair<JsVar, JsExpression> createTemporary(@Nullable JsExpression initExpression) {
072        JsVar var = new JsVar(currentScope.declareTemporary(), initExpression);
073        return Pair.create(var, (JsExpression) new JsNameRef(var.getName()));
074    }
075
076    @NotNull
077    public JsScope getScope() {
078        return currentScope;
079    }
080
081    @NotNull
082    public JsBlock jsBlock() {
083        return currentBlock;
084    }
085}