3.代码地址

coding.net可运行完整代码地址

4.项目代码

//
//  main.cpp
//  cffxq
//
//  Created by LiYuNhUi on 2018/4/8.
//  Copyright ? 2018年 LiYuNhUi. All rights reserved.
//
#include "stdlib.h"
#include "stdio.h"
#include "string.h"
#include <iostream>

using namespace std;

static char reserveWord[32][20] = {
    "auto", "break", "case", "char","const","continue","default","do",
    "double", "else", "enum", "extern", "float", "for", "goto", "if",
    "int", "long", "register", "return", "short", "signed", "sizeof", "static",
    "struct", "switch", "typedef", "union", "unsigned", "void","volatile", "while"
};

static char operatorOrDelimiter[37][10] = {
    "+", "-", "*", "/", "<", "<=", ">", ">=", "=", "==",
    "!=", ";", "(", ")", "^", ",", "\"", "\'", "#", "&",
    "&&", "|", "||", "%", "~", "<<", ">>", "[", "]", "{",
    "}", "\\", ".", "\?", ":", "!","\n"
};

int searchReserveword(char reserveWord[][20], char s[]){
    int i=0;
    for (i=0; i<32; i++){
        if (strcmp(reserveWord[i], s)==0) {
            return i+1;
        }//if
    }//for
    return -1;
}// 识别保留字

bool Letters (char letter){
    if((letter>='a'&&letter<='z')||(letter>='A'&&letter<='Z')||letter=='-')return true;
    else return false;
}//识别字母

bool Digit (char digit){
    if(digit>='0'&&digit<='9') return true;
    else return false;
}//识别数字

int cleanproject(char r[],int pnum){
    int i=0, count=0;
    char clean[1000];
    while (i<pnum) {
        if(r[i]=='/'&&r[i+1]=='/'){
            while (r[i]!='\n') {
                   i++;
            }//while
        }//跳过单行注释
        if (r[i]=='/'&&r[i+1]=='*') {
            while (!(r[i]=='*'&&r[i+1]=='/')) {
                i++;
            }//while
            i+=2;
        }//跳过多行注释
        if (r[i]!='\r'&&r[i]!='\t') {
            clean[count++]=r[i];
        }
        i++;
    }//while
    clean[count]='\0';
    strcpy(r, clean);
    return count;
}

void analysis(char project[], char take[], int &flag, int &pnum ){
    int i=0;
    int count=0;
    for (i=0; i<20; i++) {
        take[i]='\0';
    }
    while(project[pnum]==' ') {
        pnum++;
    }
    if (Letters(project[pnum])) {
        take[count++]=project[pnum];
        pnum++;
        while(Letters(project[pnum])||Digit(project[pnum])){
            take[count++]=project[pnum];
            pnum++;
        }
        take[count]='\0';
        flag=searchReserveword(reserveWord, take);
        if (flag==-1) {
            flag=100;
        }
        return;
    }
    else if (Digit(project[pnum])) {
        take[count++]=project[pnum];
        pnum++;
        while (Digit(project[pnum])) {
            take[count++]=project[pnum];
            pnum++;
        }
        take[count]='\0';
        flag=99;
        return;
    }
    else if(project[pnum]=='+'||project[pnum]=='-'||project[pnum]=='*'||project[pnum]=='/'||project[pnum]=='('||project[pnum]==')'||project[pnum]=='['||project[pnum]==']'||project[pnum]=='{'||project[pnum]=='}'||project[pnum]==';'||project[pnum]==','||project[pnum]=='\n'){
        take[count++]=project[pnum];
        pnum++;
        take[count]='\0';
        i=0;
        while (i<36) {
            if(strcmp(take, operatorOrDelimiter[i])==0){
                flag=i+33;
                return ;
            }
            i++;
        }
    }
    else if(project[pnum]=='='){
        take[count++]=project[pnum];
        if (project[++pnum]=='=') {
            take[count++]=project[pnum];
            take[count]='\0';
            flag=41;
            return;
        }
        else {
            flag=42;
        }
    }
    else if(project[pnum]=='<'){
        take[count++]=project[pnum];
        if (project[++pnum]=='=') {
            take[count++]=project[pnum];
            take[count]='\0';
            flag=38;
            return;
        }
        else {
            flag=37;
        }
    }
    else if(project[pnum]=='>'){
        take[count++]=project[pnum];
        if (project[++pnum]=='=') {
            take[count++]=project[pnum];
            take[count]='\0';
            flag=40;
            return;
        }
        else {
            flag=39;
        }
    }
}

int main(int argc, const char * argv[]) {
    char project[1000];
    char take[20];
    int pnum=0;
    int length=0;
    int flag=0;
    project[length]=getchar();
    while (project[length]!='#') {
        project[++length]=getchar();
    }
    pnum=0;
    length=cleanproject(project, length);
    int i=0;
    while (i<length){
        cout<<project[i];
        i++;
    }
    cout<<'\n';
    while(pnum<length){
        analysis(project, take, flag, pnum);
        if (flag<=32&&flag>=1) {
            printf("<%d, ->",flag);
        }
        else if(flag==99){
            printf("<%d, %s>",flag, take);
        }
        else if(flag==100){
            printf("<%d, %s>",flag, take);
        }
        else{
            if (flag==69) {
                printf("\n");
            }
            else printf("<%d, %s>",flag, take);
        }
    }
    return 0;
}

5.代码审查表

6.代码分析

·代码评价

??词法分析是计算机科学中将字符序列转换为单词序列的过程，也叫扫描器，是进行下一步计算机编译的基础。在词法分析器的编写过程中虽然并没有过多过难的设计和算法，但对程序设计者的整体程序设计能力、各功能函数的设计和应用、模块功能的实现层次及编程时的耐心和细心都有着很大的考验。李云辉同学在这方面做的很好，在自动单元测试的环节中通过所有预先设定好的测试样例，在程序的细节把控上较为完美。从此词法分析器整体来看，数据结构设置合理且全面，应用充分，函数层次分明，各功能模块可以实现相互配合实现的代码的更优化。
??·代码亮点
????·函数层次分明，易于审查及维护；
????·代码工整，各变量设置妥当；
????·充分考虑词法分析时的各种情况，做到no warning，no error。