content: /*
   * Copyright (C) 2020 ActiveJ LLC.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package io.activej.codegen.expression.impl;
  
  import io.activej.codegen.Context;
  import io.activej.codegen.expression.Expression;
  import io.activej.common.annotation.ExposedInternals;
  import org.objectweb.asm.Label;
  import org.objectweb.asm.Type;
  import org.objectweb.asm.commons.GeneratorAdapter;
  import org.objectweb.asm.commons.TableSwitchGenerator;
  
  import java.util.Arrays;
  
  import static io.activej.codegen.util.TypeChecks.checkType;
  import static io.activej.codegen.util.TypeChecks.isWidenedToInt;
  
  @ExposedInternals
  public final class TableSwitch implements Expression {
  	public final Expression value;
  	public final int[] keys;
  	public final Expression[] matchExpressions;
  	public final Expression defaultExpression;
  
  	public TableSwitch(Expression value, int[] keys, Expression[] matchExpressions, Expression defaultExpression) {
  		this.value = value;
  		this.keys = keys;
  		this.matchExpressions = matchExpressions;
  		this.defaultExpression = defaultExpression;
  	}
  
  	@Override
  	public Type load(Context ctx) {
  		GeneratorAdapter g = ctx.getGeneratorAdapter();
  
  		Type keyType = this.value.load(ctx);
  		checkType(keyType, isWidenedToInt());
  
  		class TypeRef {
  			Type type;
  		}
  
  		TypeRef returnTypeRef = new TypeRef();
  		g.tableSwitch(keys, new TableSwitchGenerator() {
  			@Override
  			public void generateCase(int key, Label end) {
  				int idx = Arrays.binarySearch(keys, key);
  				Type type = matchExpressions[idx].load(ctx);
  				g.goTo(end);
  				returnTypeRef.type = ctx.unifyTypes(returnTypeRef.type, type);
  			}
  
  			@Override
  			public void generateDefault() {
  				Type type = defaultExpression.load(ctx);
  				returnTypeRef.type = ctx.unifyTypes(returnTypeRef.type, type);
  			}
  		});
  
  		return returnTypeRef.type;
  	}
  }
  