Токенизация и синтаксический анализ текстового файла (редактировать текстовый файл ASCII списка решений) Задача C

Question

Я новичок в программировании и в стеке, и решил начать с изучения цели c.

В глубине, я знаю.

Я застрял, пытаясь найти лучший способ для анализа файла EDL. В основном это текстовый файл ASCII размером не более 100 КБ. Вот структура типичного cmx3600 edl:

TITLE:   EP1 FINAL.EDL SECTION2
FCM: NON-DROP FRAME
001  A199_C00 V     C        20:38:24:15 20:38:26:04 10:30:00:02 10:30:01:16
* SOURCE FILE: A199_C008_0915AH_001
002  A199_C00 V     C        20:34:48:17 20:34:51:23 10:30:01:16 10:30:04:22
* SOURCE FILE: A199_C007_0915VE_001

Я пытаюсь найти наилучший способ разбора или сканирования каждого элемента в поля / массивы, т. Е.

editNum = 001
tapeName = A199_C00
channel = V
Operation = C
sourceIn = 20:38:24:15
sourceOut = 20:38:26:04
recIn = 10:30:00:02
recOut = 10:30:01:16
sourceFile = A199_C008_0915AH_001

Это мой код:

-(IBAction)importEdl:(id)sender {    

    //defines an Array of allowed file types with file extension ".EDL and .edl"

    NSOpenPanel *myPanel = [NSOpenPanel openPanel];
    NSArray *fileTypes = [NSArray arrayWithObjects:@"EDL", @"edl", nil];
    myPanel.allowedFileTypes = fileTypes;
    myPanel.allowsMultipleSelection = NO;

    if ([myPanel runModal] == NSOKButton)
    {            

    NSString *theFilePath = [myPanel filename];
    NSString *psEdlFile = [NSString stringWithContentsOfFile:theFilePath encoding:NSASCIIStringEncoding error:NULL];
        // Reads the file as one string. EDL's are simple ASCII text files of roughly 50KB.

    NSArray *psEdlLines = [psEdlFile componentsSeparatedByCharactersInSet:[NSCharacterSet newlineCharacterSet]];   
        // Separates the data into lines.

    if([psEdlLines count] == 0)
    {
        NSLog(@"Error!");                                  
    } //prints error if EDL file has no events.


    NSUInteger count;
    int i;
    for (i = 0, count = [psEdlLines count]; i < count; i = i + 1)
    {
        NSString *lineStrings = [psEdlLines objectAtIndex:i];
        NSLog(@"Line %d is %@",i+1,lineStrings);

    //NSArray *linesEnum = [psEdlLines objectAtIndex:i];
        //this creates an array of lines

    //NSLog(@"index is: %d %@",i, linesEnum);
    }

    }                

}

@end

Вывод:

2012-03-20 15:22:08.956 TestProgram[412:903] Line 1 is TITLE:   EP1 FINAL.EDL SECTION2
2012-03-20 15:22:08.957 TestProgram[412:903] Line 2 is FCM: NON-DROP FRAME
2012-03-20 15:22:08.957 TestProgram[412:903] Line 3 is 001  A199_C00 V     C        20:38:24:15 20:38:26:04 10:30:00:02 10:30:01:16
2012-03-20 15:22:08.957 TestProgram[412:903] Line 4 is * SOURCE FILE: A199_C008_0915AH_001
2012-03-20 15:22:08.957 TestProgram[412:903] Line 5 is 002  A199_C00 V     C        20:34:48:17 20:34:51:23 10:30:01:16 10:30:04:22
2012-03-20 15:22:08.957 TestProgram[412:903] Line 6 is * SOURCE FILE: A199_C007_0915VE_001
2012-03-20 15:22:08.957 TestProgram[412:903] Line 7 is 003  A199_C00 V     C        20:42:32:01 20:42:35:19 10:30:04:22 10:30:08:15
2012-03-20 15:22:08.957 TestProgram[412:903] Line 8 is * SOURCE FILE: A199_C009_0915RX_001
2012-03-20 15:22:08.957 TestProgram[412:903] Line 9 is 
2012-03-20 15:22:08.958 TestProgram[412:903] Line 10 is 

Я не очень далеко, как вы можете видеть. Любые идеи будут высоко оценены. Заранее спасибо, Пит.

Answer 1

Больше прогресса.

if ([lineScanner scanInt:&eventNum])
    {
        // parse the event into fields

        // does not work if edl contains dissolve or wipe
        // need to automatically convert dissolves into cuts

         NSString *editNum;
         NSString *reelName;
         NSString *channels;
         NSString *operation;
         //NSString *opDuration;
         NSString *sourceInTime;
         NSString *sourceOutTime;
         NSString *destInTime;
         NSString *destOutTime;

        NSScanner *elementScanner = [NSScanner scannerWithString:line];

        //NSString *token = [NSString string];
        NSCharacterSet *divider = [NSCharacterSet whitespaceCharacterSet];

        [elementScanner scanUpToCharactersFromSet:divider intoString:&editNum];
        [elementScanner scanUpToCharactersFromSet:divider intoString:&reelName];
        [elementScanner scanUpToCharactersFromSet:divider intoString:&channels];
        [elementScanner scanUpToCharactersFromSet:divider intoString:&operation];
        //[elementScanner scanUpToCharactersFromSet:divider intoString:&opDuration];
        [elementScanner scanUpToCharactersFromSet:divider intoString:&sourceInTime];
        [elementScanner scanUpToCharactersFromSet:divider intoString:&sourceOutTime];
        [elementScanner scanUpToCharactersFromSet:divider intoString:&destInTime];
        [elementScanner scanUpToCharactersFromSet:divider intoString:&destOutTime];


        NSLog(@"Event\tReelName\tChannels\tOperation\tSource In\tSource Out\tDest In\t\tDest Out");
        NSLog(@"%@\t%@\t%@\t\t\t%@\t\t\t%@\t%@\t%@\t%@", 
              editNum, reelName, channels, operation, /*opDuration,*/ sourceInTime, sourceOutTime, destInTime,destOutTime);

    }

Выводит следующее.

2012-03-29 15:54:15.489 TestProgram[2414:903] Scanner:Title = EP1 FINAL.EDL SECTION2
2012-03-29 15:54:15.489 TestProgram[2414:903] Event ReelName    Channels    Operation   Source In   Source Out  Dest In     Dest Out
2012-03-29 15:54:15.489 TestProgram[2414:903] 001   A180_C00    V           C           20:29:12:18 20:29:13:21 10:46:39:20 10:46:40:23
2012-03-29 15:54:15.489 TestProgram[2414:903] Comment for event    001 * SOURCE FILE: A180_C001_09138L_001
2012-03-29 15:54:15.489 TestProgram[2414:903] Event ReelName    Channels    Operation   Source In   Source Out  Dest In     Dest Out
2012-03-29 15:54:15.490 TestProgram[2414:903] 002   A181_C01    V           C           22:10:03:03 22:10:05:09 10:46:40:23 10:46:43:04
2012-03-29 15:54:15.490 TestProgram[2414:903] Comment for event    002 * SOURCE FILE: A181_C010_0913EA_001
2012-03-29 15:54:15.490 TestProgram[2414:903] Event ReelName    Channels    Operation   Source In   Source Out  Dest In     Dest Out
2012-03-29 15:54:15.490 TestProgram[2414:903] 003   A181_C01    V           C           22:10:05:09 22:10:05:10 10:46:43:04 10:46:43:09
2012-03-29 15:54:15.490 TestProgram[2414:903] Effect for event     003    M2   A181_C01       000.0                22:10:05:09
2012-03-29 15:54:15.491 TestProgram[2414:903] Comment for event    003 * * FREEZE FRAME
2012-03-29 15:54:15.491 TestProgram[2414:903] Comment for event    003 * SOURCE FILE: A181_C010_0913EA_001

Answer 2

Хорошо,

Я пытался выяснить это, используя NSScanner и префиксы строк. Я могу сканировать строки (события), которые начинаются с цифры, а также изолировать комментарии и эффекты, связанные с каждым соответствующим событием.

вот код:

for (NSString *line in psEdlLines)// just an NSLog test before scanning process 
    {
        NSLog(@"Before scanner: %@",line);//All lines.
    }

for (NSString *line in psEdlLines)// Scanner process.
        {

        int eventNum;
        NSString *comment;
        NSString *effect;
        NSScanner *lineScanner = [NSScanner scannerWithString:line];

while ([lineScanner scanInt:&eventNum]) 
        {
            NSLog(@"Scanner: Event only: %@:", line);
        }

    if ([line hasPrefix:@"*"]) 
        {
                comment = [line substringFromIndex:0];
            NSLog(@"Comment for event    %03i: %@",eventNum, comment);
        }

    if ([line hasPrefix:@"M2"]) 
            {
                effect = [line substringFromIndex:0];
            NSLog(@"Effect for event     %03i:    %@",eventNum, effect);
            }
}
@end

Вот вывод из файла edl 3 событий:

2012-03-23 14:23:48.040 TestProgram[1621:903] Before scanner: TITLE:   EP1 FINAL.EDL SECTION2
2012-03-23 14:23:48.040 TestProgram[1621:903] Before scanner: FCM: NON-DROP FRAME
2012-03-23 14:23:48.040 TestProgram[1621:903] Before scanner: 001  A180_C00 V     C        20:29:12:18 20:29:13:21 10:46:39:20 10:46:40:23
2012-03-23 14:23:48.040 TestProgram[1621:903] Before scanner: * SOURCE FILE: A180_C001_09138L_001
2012-03-23 14:23:48.040 TestProgram[1621:903] Before scanner: 002  A181_C01 V     C        22:10:03:03 22:10:05:09 10:46:40:23 10:46:43:04
2012-03-23 14:23:48.040 TestProgram[1621:903] Before scanner: * SOURCE FILE: A181_C010_0913EA_001
2012-03-23 14:23:48.040 TestProgram[1621:903] Before scanner: 003  A181_C01 V     C        22:10:05:09 22:10:05:10 10:46:43:04 10:46:43:09
2012-03-23 14:23:48.040 TestProgram[1621:903] Before scanner: M2   A181_C01       000.0                22:10:05:09
2012-03-23 14:23:48.041 TestProgram[1621:903] Before scanner: * * FREEZE FRAME
2012-03-23 14:23:48.041 TestProgram[1621:903] Before scanner: * SOURCE FILE: A181_C010_0913EA_001
2012-03-23 14:23:48.041 TestProgram[1621:903] Before scanner: 
2012-03-23 14:23:48.041 TestProgram[1621:903] Scanner: Event only: 001  A180_C00 V     C        20:29:12:18 20:29:13:21 10:46:39:20 10:46:40:23:
2012-03-23 14:23:48.041 TestProgram[1621:903] Comment for event    001 * SOURCE FILE: A180_C001_09138L_001
2012-03-23 14:23:48.041 TestProgram[1621:903] Scanner: Event only: 002  A181_C01 V     C        22:10:03:03 22:10:05:09 10:46:40:23 10:46:43:04:
2012-03-23 14:23:48.041 TestProgram[1621:903] Comment for event    002 * SOURCE FILE: A181_C010_0913EA_001
2012-03-23 14:23:48.042 TestProgram[1621:903] Scanner: Event only: 003  A181_C01 V     C        22:10:05:09 22:10:05:10 10:46:43:04 10:46:43:09:
2012-03-23 14:23:48.042 TestProgram[1621:903] Effect for event     003    M2   A181_C01       000.0                22:10:05:09
2012-03-23 14:23:48.042 TestProgram[1621:903] Comment for event    003 * * FREEZE FRAME
2012-03-23 14:23:48.042 TestProgram[1621:903] Comment for event    003 * SOURCE FILE: A181_C010_0913EA_001

Я могу добавить операторы if для всех возможных случаев, которые могут возникнуть из строк комментариев в файле edl. Это должно позволить мне обрабатывать каждый элемент строки по мере необходимости в цикле.

Это выглядит хорошо?

Спасибо, Пит.