net.hasor.dataql.compiler.cc.TernaryExprInstCompiler Maven / Gradle / Ivy
/*
* Copyright 2008-2009 the original author or authors.
*
* 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 net.hasor.dataql.compiler.cc;
import net.hasor.dataql.compiler.qil.CompilerContext;
import net.hasor.dataql.compiler.qil.InstCompiler;
import net.hasor.dataql.compiler.qil.InstQueue;
import net.hasor.dataql.compiler.qil.Label;
import net.hasor.dataql.parser.ast.Expression;
import net.hasor.dataql.parser.ast.expr.TernaryExpression;
/**
* 三元运算表达式
* @author 赵永春 ([email protected])
* @version : 2017-03-23
*/
public class TernaryExprInstCompiler implements InstCompiler {
@Override
public void doCompiler(TernaryExpression astInst, InstQueue queue, CompilerContext compilerContext) {
Expression testExpr = astInst.getTestExpression();
Expression thenExpr = astInst.getThenExpression();
Expression elseExpr = astInst.getElseExpression();
Label elseLabel = queue.labelDef();
Label endLabel = queue.labelDef();
//
// .测试表达式
compilerContext.findInstCompilerByInst(testExpr).doCompiler(queue);
instLocation(queue, testExpr.expressCodeLocation());
queue.inst(IF, elseLabel);//如果判断失败，执行第二个表达式
//
// .第一个表达式
compilerContext.findInstCompilerByInst(thenExpr).doCompiler(queue);
queue.inst(GOTO, endLabel);//第一个表达式执行成功的话就跳转到 end
//
// .第二个表达式
queue.inst(LABEL, elseLabel);
compilerContext.findInstCompilerByInst(elseExpr).doCompiler(queue);
queue.inst(LABEL, endLabel);
}
}