编译原理中的词法分析需要进行错误报告吗

编译原理中的词法分析需要进行错误报告吗？还是应该一并在语法分析中给出。
如果需要，那么需要判断哪几类错误？

词法分析中需要进行处理和报告的错误为：源程序中出现的不符合文法的字符，标识符等等。
这些一定要在词法分析中完成，搁到后面会很麻烦。
其余错误，如类型不匹配，返回值出错，语句语法错误等，在语法分析过程中进行。

编译的词法分析，一般是先画一个状态转换图，一般是有多少分支，就有多少if语句，分支里面再分（可能有循环语句）。注意记住词的类别和词的字符串，请以以下代码为例，理会一下词法分析的大致过程。 while(s[i]!='#') { while(s[i]==' '||s[i]=='\t'||s[i]=='\n') { if(s[i]=='\n') line++; i++; } if(s[i]=='#') break; j=i; if(s[i]>='a'&&s[i]<='z'||s[i]>='a'&&s[i]<='z') { i++; while(s[i]>='a'&&s[i]<='z'||s[i]>='a'&&s[i]<='z'||s[i]>='0'&&s[i]<='9') i++; if((i-j)==2&&s[j]=='i'&&s[j+1]=='f') { strcpy(dancishuzu[dancigeshu].name,"if"); dancishuzu[dancigeshu].bianhao=4; dancigeshu++; } else if((i-j)==3&&s[j]=='i'&&s[j+1]=='n'&&s[j+2]=='t') { strcpy(dancishuzu[dancigeshu].name,"int"); dancishuzu[dancigeshu].bianhao=2; dancigeshu++; } else if((i-j)==3&&s[j]=='f'&&s[j+1]=='o'&&s[j+2]=='r') { strcpy(dancishuzu[dancigeshu].name,"for"); dancishuzu[dancigeshu].bianhao=6; dancigeshu++; } else if((i-j)==4&&s[j]=='m'&&s[j+1]=='a'&&s[j+2]=='i'&&s[j+3]=='n') { strcpy(dancishuzu[dancigeshu].name,"main"); dancishuzu[dancigeshu].bianhao=1; dancigeshu++; } else if ((i-j)==4&&s[j]=='c'&&s[j+1]=='h'&&s[j+2]=='a'&&s[j+3]=='r') { strcpy(dancishuzu[dancigeshu].name,"char"); dancishuzu[dancigeshu].bianhao=3; dancigeshu++; } else if ((i-j)==4&&s[j]=='e'&&s[j+1]=='l'&&s[j+2]=='s'&&s[j+3]=='e') { strcpy(dancishuzu[dancigeshu].name,"else"); dancishuzu[dancigeshu].bianhao=5; dancigeshu++; } else if ((i-j)==5&&s[j]=='w'&&s[j+1]=='h'&&s[j+2]=='i'&&s[j+3]=='l'&&s[j+4]=='e') { strcpy(dancishuzu[dancigeshu].name,"while"); dancishuzu[dancigeshu].bianhao=7; dancigeshu++; } else{ dancishuzu[dancigeshu].bianhao=10; count=0; while(j='0'&&s[i]<='9') { while(s[i]>='0'&&s[i]<='9') i++; dancishuzu[dancigeshu].bianhao=11; count=0; while(j') { if(s[i+1]=='=') { dancishuzu[dancigeshu].bianhao=28; strcpy(dancishuzu[dancigeshu].name,">="); dancigeshu++; i+=2; } else { i++; dancishuzu[dancigeshu].bianhao=26; strcpy(dancishuzu[dancigeshu].name,">"); dancigeshu++; } } else if(s[i]=='<') { if(s[i+1]=='=') { dancishuzu[dancigeshu].bianhao=29; strcpy(dancishuzu[dancigeshu].name,"<="); dancigeshu++; i+=2; } else { i++; dancishuzu[dancigeshu].bianhao=27; strcpy(dancishuzu[dancigeshu].name,"<"); dancigeshu++; } } else if(s[i]=='!'&&s[i+1]=='=') { dancishuzu[dancigeshu].bianhao=31; strcpy(dancishuzu[dancigeshu].name,"!="); dancigeshu++; i+=2; } else { printf("\nline:%derror!",line); i++; return; } }