Use the linked list to solve the problem of too many if statements (C/C ++ implementation)

After implementation with the design pattern, I suddenly found that the so-called design pattern is actually not a linked list in the C language? If the current node can be processed, it cannot be processed by the next node. Not to mention, design message of the code message class. h copy the Code # ifndef MESSAGE_H # define TRUE 1 # define FALSE 0 typedef struct {int sender; int isSend; int isCharge; char date [8];} Message; message * makeMessage (const int sender, const char * date); void setSendFlag (Message * const message); void setChargeFlag (Message * const message ); int isSameDate (const Message * const message, const char * con St date); char * format (const Message * const message); const char * boolStr (const int value); # endif copy code message. c copy the Code # include <assert. h> # include <string. h> # include <stdlib. h> # include <stdio. h> # include "message. h "Message * makeMessage (const int sender, const char * date) {Message * message = (Message *) malloc (sizeof (Message); assert (message! = NULL); message-> sender = sender; message-> isSend = FALSE; message-> isCharge = FALSE; strncpy (message-> date, date, 8 ); return message;} const char * boolStr (const int value) {return value = TRUE? "TRUE": "FALSE";} char * format (const Message * const message) {# define BUF_SIZE 1024 static char buffer [BUF_SIZE]; memset (& buffer, 0, BUF_SIZE); snprintf (char *) & buffer, BUF_SIZE, "Message <% d isSend: % s isCharge: % s> \ n", \ message-> sender, boolStr (message-> isSend), boolStr (message-> isCharge); return (char *) buffer;} void setSendFlag (Message * const message) {message-> isSend = TRUE;} void setCharg EFlag (Message * const message) {message-> isCharge = TRUE;} int isSameDate (const Message * const message, const char * const date) {if (strncmp (message-> date, date, 8) = 0) {return TRUE;} else {return FALSE ;}} copy the code testMessage. c copy the Code # include <stdio. h> # include "message. h "# include" gtest/gtest. h "TEST (MESSAGE, makeMessage) {Message * message = makeMessage (1," 20131212 "); EXPECT_EQ (1, message-> sender); EXPECT_STREQ ("Message <1 isSend: FALSE isCharge: FALSE> \ n", format (message);} copy the implementation node of the code linked list class. h copy the Code # ifndef NOTE_H # define NOTE_H typedef struct Node {void * ptr; struct Node * next;} Node; Node * makeListWithArray (void * array [], int length ); void foreach (Node * list, void (* process) (Node *); # endif copies the code node. c copy the Code # include <stdlib. h> # include <assert. h> # include "node. h "Node * makeListWithArray (void * arra Y [], int length) {int I; Node * last = NULL; assert (array! = NULL & length> 0); for (I = length-1; I> = 0; I --) {Node * node = (Node *) malloc (sizeof (Node); node-> ptr = array [I]; node-> next = last; last = node;} return last ;} void foreach (Node * list, void (* process) (Node *) {Node * current = NULL; assert (list! = NULL & process! = NULL); for (current = list; current! = NULL; current = current-> next) {process (current) ;}} copy the code testNode. c copy the Code # include <stdio. h> # include "node. h "# include" gtest/gtest. h "void printNode (Node * node) {static int I = 0; int data [] = {1, 2, 3}; EXPECT_EQ (data [I], * (int *) node-> ptr); I ++;} TEST (NODE, makeListWithArray) {int I; int data [] = {1, 2, 3 }; void * aSet [] = {& data [0], & data [1], & data [2]}; Node * list = makeListWithArray (aSet, 3 ); foreach (list, printNode);} copy the code program entry implementation (main. c) copy the Code # include <stdio. h> # include <string. h> # include "message. h "# include" node. h "# define FALSE 0 # define TRUE 1 typedef int BOOL; typedef BOOL (* FuncIsAllowSend) (Message *, Node *); BOOL isAllowSendCheckDate (Message * message, Node * node) {FuncIsAllowSend isAllowSend = NULL; if (strcmp (message-> date, "20130101") = 0) {return FALSE;} isAllowSend = (FuncIsAllowSend) node-> next-> ptr; return isAllowSend (message, node-> next);} BOOL isAllowSendCheckWhiteList (Message * message, Node * node) {FuncIsAllowSend isAllowSend = NULL; if (message-> sender = 10) {return TRUE;} isAllowSend = (FuncIsAllowSend) node-> next-> ptr; return isAllowSend (message, node-> next );} BOOL isAllowSendWithDefault (Message * message, Node * node) {setChargeFlag (message); return TRUE;} int main () {Message * message = makeMessage (1, "20131212 "); void * actionList [] = {(void *) & isAllowSendCheckDate, (void *) & isAllowSendCheckWhiteList, (void *) & isAllowSendWithDefault}; Node * theList = makeListWithArray (actionList, sizeof (actionList)/4); FuncIsAllowSend isAllowSend = (FuncIsAllowSend) theList-> ptr; if (isAllowSend (message, theList) = TRUE) {setSendFlag (message );} printf ("% s \ n", format (message);} the copy code style is actually C, however, to use gtest, you have to use g ++ to compile and debug the program. The command is as follows: copy the Code # prerequisites: I have compiled gtest into a library and placed it in the system directory g ++-c message. cg ++-c testMessage. cg ++ message. o testMessage. o-lgtest-lpthread. /. out g ++-c node. cg ++-c testNode. cg ++ node. o testNode. o-lgtest-lpthread. /. out g ++-c main. cg ++ message. o node. o main. o. /. out