实验4 LR(1)分析法

《实验4 LR(1)分析法》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。

1、河南工业大学实验报告课程名称编译原理_实验项目实验四LR(1)分析法院系____信息科学与工程学院____专业班级计科F1402班姓名苏朋辉学号201416010211指导老师侯惠芳日期2017.5.6批改日期成绩一.实验目的1．掌握LR(1)分析法的基本原理2．掌握LR(1)分析表的构造方法3．掌握LR(1)驱动程序的构造方法二.实验内容及要求构造LR(1)分析程序，利用它进行语法分析，判断给出的符号串是否为该文法识别的句子，了解LR（K）分析方法是严格的从左向右扫描，和自底向上的语法分析方法。根据某一文法编制调试LR（1）分析程序，以便对任意输入的符号串进行分析。本次实验的目的主

2、要是加深对LR（1）分析法的理解。程序输入/输出示例：对下列文法，用LR（1）分析法对任意输入的符号串进行分析：（1）E->E+T（2）E->E—T（3）T->T*F（4）T->T/F（5）F->(E)（6）F->i输出的格式如下：(1)LR（1）分析程序，编制人：姓名，学号，班级(2)输入一以#结束的符号串(包括+—*/（）i#)：在此位置输入符号串(3)输出过程如下：步骤状态栈符号栈剩余输入串动作10#i+i*i#移进(4)输入符号串为非法符号串(或者为合法符号串)备注：(1)在“所用产生式”一列中如果对应有推导则写出所用产生式；如果为匹配终结符则写明匹配的终结符；如分析异常出错

3、则写为“分析出错”；若成功结束则写为“分析成功”。(2)在此位置输入符号串为用户自行输入的符号串。注意：1.表达式中允许使用运算符（+-*/）、分割符（括号）、字符i，结束符#；2.如果遇到错误的表达式，应输出错误提示信息（该信息越详细越好）；3.对学有余力的同学，测试用的表达式事先放在文本文件中，一行存放一个表达式，同时以分号分割。同时将预期的输出结果写在另一个文本文件中，以便和输出进行对照；4．可采用的其它的文法。一.实验过程3.1代码如下：#include#include#include#includeusi

4、ngnamespacestd;//初始化预测分析表stringaction[12][6]={{"s5","error","error","s4","error","error"},{"error","s6","error","error","error","acc"},{"error","r2","s7","error","r2","r2"},{"error","r4","r4","error","r4","r4"},{"s5","error","error","s4","error","error"},{"error","r6","r6","error","r6","r6"},{"

5、s5","error","error","s4","error","error"},{"s5","error","error","s4","error","error"},{"error","s6","error","error","s11","error"},{"error","r1","r7","error","r1","r1"},{"error","r3","r3","error","r3","r3"},{"error","r5","r5","error","r5","r5"}};stringgo[12][3]={{"1","2","3"},{"error","error","

6、error"},{"error","error","error"},{"error","error","error"},{"8","2","3"},{"error","error","error"},{"error","9","3"},{"error","error","10"},{"error","error","error"},{"error","error","error"},{"error","error","error"},{"error","error","error"},};charVt[6]={'i','+','*','(',')','#'};//终结符表string

7、LR[6]={"E->E+T","E->T","T->T*F","T->F","F->(E)","F->i"};//LR文法stackS;//状态栈stackX;//符号栈charinput[10];//输入字符intnum(strings){//判断字符串中的数字inti;stringstr="";for(intj=0;j='0'&&s[j]<='9')str=str+s[j];}i