QB64.org Forum

Active Forums => QB64 Discussion => Topic started by: Pete on February 21, 2020, 10:33:42 am

Title: Just parsing along some information...
Post by: Pete on February 21, 2020, 10:33:42 am

Here is a nice little example of how parsing can help find changes in a file database...

Code: QB64: [Select]

1. orig_concat$ = "Pete|Steve|Bill|Norma Jean|Fell|"
2. new_concat$ = "Pete|Steve|Norma Jean|Fell|"
3. seed = 1
4. marker$ = "|"
5. DO
6.     x$ = MID$(orig_concat$, seed, INSTR(seed, orig_concat$, marker$) - seed)
7.     seed = seed + LEN(x$) + LEN(marker$)
8.     PRINT x$, seed, LEN(orig_concat$)
9.     IF INSTR(new_concat$, x$) = 0 THEN
10.         COLOR 4, 0: PRINT MID$(x$, 1, LEN(x$)); " was deleted. Good-bye "; MID$(x$, 1, LEN(x$)); "!": COLOR 7, 0
11.     END IF
12. LOOP UNTIL seed > LEN(orig_concat$)
13.  

Pete

Title: Re: Just parsing along some information...
Post by: TempodiBasic on February 21, 2020, 05:50:11 pm

Hi Pete
very interesting concept!
But for my slow mind I prefer to have a more explicit output
like this

Code: QB64: [Select]

1. orig_concat$ = "Pete|Steve|Bill|Norma Jean|Fell|"
2. new_concat$ = "Pete|Steve|Norma Jean|Fell|"
3. seed = 1
4. marker$ = "|"
5. seed2 = 1
6. DO
7.     x$ = MID$(orig_concat$, seed, INSTR(seed, orig_concat$, marker$) - seed)
8.     seed = seed + LEN(x$) + LEN(marker$)
9.     PRINT x$, seed, LEN(orig_concat$);
10.  
11.     IF INSTR(new_concat$, x$) = 0 THEN
12.         COLOR 4, 0: PRINT MID$(x$, 1, LEN(x$)); " was deleted. Good-bye "; MID$(x$, 1, LEN(x$)); "!": COLOR 7, 0
13.     ELSE
14.         Y$ = MID$(new_concat$, seed2, INSTR(seed2, new_concat$, marker$) - seed2)
15.         seed2 = seed2 + LEN(Y$) + LEN(marker$)
16.         ' PRINT Y$, STR$(seed2), STR$(LEN(new_concat$))
17.         PRINT Y$ + "   " + STR$(seed2) + "   " + STR$(LEN(new_concat$))
18.     END IF
19. LOOP UNTIL seed > LEN(orig_concat$)
20.  

:-)

Text Only | Text with Attachments