注释转换应用实例

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注释转换

原理图：

这张状态图很完美的说明了一切情况，以这张图为框架来具体实现注释装换代码。

代码如下：

//convert.h

#ifndef __CONVERT_H__#define __CONVERT_H__#include<stdio.h>typedef enum STATE{ NUL_STATE, C_STATE, CPP_STATE, END_STATE}STATE;void DealConvertwork(FILE* pfin, FILE* pfout);void Dealnul_state(FILE* pfin, FILE* pfout, STATE* p);void Dealc_state(FILE* pfin, FILE* pfout, STATE* p);void Dealcpp_state(FILE* pfin, FILE* pfout, STATE* p);#endif

//convert.c

#include<stdio.h>#include"convert.h"void DealConvertwork(FILE* pfin, FILE* pfout)//状态机的总体框架{ STATE state = NUL_STATE; while (state != END_STATE) { switch (state) { case NUL_STATE: Dealnul_state(pfin, pfout, &state); break; case C_STATE: Dealc_state(pfin, pfout, &state); break; case CPP_STATE: Dealcpp_state(pfin, pfout, &state); break; default: END_STATE; break; } }}void Dealnul_state(FILE* pfin, FILE* pfout, STATE* p)//对空状态的处理 { int first = fgetc(pfin); switch (first) { case '/':{ int second = fgetc(pfin); switch (second) { case '*':{ fputc('/', pfout); fputc('/', pfout); *p = C_STATE; } break; case '/':{ fputc(first, pfout); fputc(second, pfout); *p = CPP_STATE; } break; default: fputc(first, pfout); fputc(second, pfout); break; } } break; case EOF: *p = END_STATE; break; default: fputc(first, pfout); break; }}void Dealc_state(FILE* pfin, FILE* pfout, STATE* p)//处理c状态{ int first = fgetc(pfin); switch (first) { case '*':{ int second = fgetc(pfin); switch (second) { case '/':{ int third = fgetc(pfin); } fputc('\n', pfout); *p = NUL_STATE; break; case '*': ungetc(second, pfin); fputc(first, pfout); break; default: fputc(first, pfout); fputc(second, pfout); break; } } break; case '\n': fputc('\n', pfout); fputc('/', pfout); fputc('/', pfout); break; default: fputc(first, pfout); break; }}void Dealcpp_state(FILE* pfin, FILE* pfout, STATE* p)//处理c++状态{ int first = fgetc(pfin); switch (first) { case '\n': fputc('\n', pfout); *p = NUL_STATE; break; case EOF: *p = END_STATE; break; default: fputc(first, pfout); break; }}

//test.c

#define _CRT_SECURE_NO_DEPRECATE 1#include<stdio.h>#include<errno.h>#include<stdlib.h>#include<windows.h>#include"convert.h"int main(){ FILE* pfin = fopen("input.c", "r");//打开文件 FILE* pfout = fopen("output.c", "w"); if (pfin == NULL) { perror("open for read"); exit(EXIT_FAILURE); } if (pfout == NULL)//如果打开失败则关闭已被打开的待转换文件 { fclose(pfin); perror("open for write"); exit(EXIT_FAILURE); } DealConvertwork(pfin, pfout); fclose(pfin);//最后统一关闭打开的文件 fclose(pfout); system("pause"); return 0;}

总结

1，这是一次状态机的实例应用；2，有时杂乱无章的代码实现用状态机可能相对简单一些，把该有的状态列举出来，分析转换状态。这样考虑问题也会全面一些，有限状态机非常实用。

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