/*
Program: tokenization.c (Report comments/bugs to chikh@yuntech.edu.tw)
Function: 輸入運算相關的文字串，從中提取關鍵資訊，為作業的預備暖身 
Notes: 輸入可為 
	w={"Mary":10, "Tom":3, "Charlie":5, "Bob":6, "Dickens":20, 4:9, "z":0, "Za":12, "aZ":8}
	del w["Dickens"]
	w["Mary"]=1
	w["Tom"]+=2
	w[4]?
	w?
*/
 
#include <stdio.h>	/* for sscanf(), printf() */
#include <string.h>	/* for strstr(), strtok(), strtok_r() */

int main()
{ 
	char  *token, key[12], line[128];
	const char *s = " ={},";	/* 分隔符記的字元 */ 
	int   value, i = 0;
	char  *rest;
   	
   	printf("\n*** 從字串讀取符記(token)程式 ***\n\n輸入存取字典的陳述，逕按<Enter>結束程式\n");
   	while (1) {
   		printf("\n指令 => ");
   		fgets(line,128,stdin);		/* 使用gets()讀取也可以，但因gets()未設讀入字元數的限制，可能導致儲存輸入字元的陣列空間爆掉 */ 
   		if (line[0]=='\n') break;	/* 輸入空字串則跳離此迴圈 */ 
   		if (strstr(line,"{")) {		/* line含有"{" */ 
   			sscanf(line,"w = {%[^}]}",line);
   			/* printf("大括弧內字串 %s\n",line); */
			rest = line;
			while (token = strtok_r(rest,s,&rest)) { /* strtok_r()的用法可參見 http://bit.ly/3VcvbbZ */ 
    			/* printf("%s\n",token); */ 
    			if (strstr(token,":")) {/* token含有":" */ 
    				sscanf(token,"%[^:]:%d",key,&value);
    				printf("Token #%d: 鍵=%s; 值=%d\n",++i,key,value);
				} 
   			}
		}
		else if (strstr(line,"del")) {	/* line含有"del" */ 
			sscanf(line,"del w[%[^]]]",key);
   			printf("刪除運算：鍵=%s\n",key);
		}
   		else if (strstr(line,"+=")) {	/* line含有"+=" */ 
   			sscanf(line,"w[%[^]]] +=%d",key,&value);
   			printf("遞增運算：鍵=%s；運算元=%d\n",key,value);
		}
   		else if (strstr(line,"=")) {	/* line含有"=" */
   			sscanf(line,"w[%[^]]] = %d",key,&value);
   			printf("指派運算：鍵=%s; 運算元=%d\n",key,value);
		}
		else if (sscanf(line,"w[%[^]]]?",key)==1) 
			printf("讀值運算：鍵=%s\n",key);
		else if (strstr(line,"?"))
			printf("顯示整個字典內容(請同學實作，此為作業的一部分)\n");
		else 
			printf("語法無法辨認，sorry!\n");
	}
   	
   	printf("\n程式結束，bye ~\n");
   	return 0;
}