Tokenize NSString en Objective-C

Question

¿Cuál es la mejor manera de tokenizar/dividir un NSString en Objective-C?

Answer 1

encontrado esto en http://borkware.com/quickies/one?topic=NSString (enlace útil):

NSString *string = @"oop:ack:bork:greeble:ponies"; 
NSArray *chunks = [string componentsSeparatedByString: @":"]; 

Espero que esto ayude!

Adam

Answer 2

Si lo que desea es dividir una cadena, utilice -[NSString componentsSeparatedByString:]. Para tokenización más compleja, use la clase NSScanner.

Answer 3

Si sus necesidades de tokenización son más complejos, echa un vistazo a mi código abierto Cacao Cadena tokenizing/kit de herramientas de análisis: ParseKit:

http://parsekit.com

Para sencilla división de cadenas utilizando un char delimitador (como ':') , ParseKit definitivamente sería excesivo. Pero, nuevamente, para necesidades complejas de tokenización, ParseKit es extremadamente poderoso/flexible.

Ver también ParseKit Tokenization documentation.

Answer 4

Todo el mundo ha mencionado componentsSeparatedByString: pero también se puede utilizar CFStringTokenizer (recordar que un NSString y CFString son intercambiables) que tokenize lenguajes naturales también (como el chino/japonés que no divide las palabras en los espacios).

Answer 5

Si desea realizar token en varios caracteres, puede usar componentsSeparatedByCharactersInSet de NSString. NSCharacterSet tiene algunos prácticos conjuntos prefabricados como el whitespaceCharacterSet y el illegalCharacterSet. Y tiene inicializadores para rangos Unicode.

También se pueden combinar los conjuntos de caracteres y los utilizan para tokenize, así:

// Tokenize sSourceEntityName on both whitespace and punctuation. 
NSMutableCharacterSet *mcharsetWhitePunc = [[NSCharacterSet whitespaceAndNewlineCharacterSet] mutableCopy]; 
[mcharsetWhitePunc formUnionWithCharacterSet:[NSCharacterSet punctuationCharacterSet]]; 
NSArray *sarrTokenizedName = [self.sSourceEntityName componentsSeparatedByCharactersInSet:mcharsetWhitePunc]; 
[mcharsetWhitePunc release]; 

Sé consciente de que componentsSeparatedByCharactersInSet producirá cuerdas en blanco si encuentra más de un miembro del charSet en una fila, por lo que podría querer probar para longitudes menores que 1.

Answer 6

Tuve un caso en el que tuve que dividir la salida de la consola después de una consulta LDAP con ldapsearch. Primero configure y ejecute NSTask (encontré una buena muestra de código aquí: Execute a terminal command from a Cocoa app). Pero luego tuve que dividir y analizar el resultado para extraer solo los nombres del servidor de impresión de Ldap-query-output. Desafortunadamente, es una manipulación de cadenas bastante tediosa, lo que no sería un problema en absoluto si manipuláramos C-strings/arrays con operaciones simples de C-array. Así que aquí está mi código usando objetos de cacao. Si tienes mejores sugerencias, házmelo saber.

//as the ldap query has to be done when the user selects one of our Active Directory Domains 
//(an according comboBox should be populated with print-server names we discover from AD) 
//my code is placed in the onSelectDomain event code 

//the following variables are declared in the interface .h file as globals 
@protected NSArray* aDomains;//domain combo list array 
@protected NSMutableArray* aPrinters;//printer combo list array 
@protected NSMutableArray* aPrintServers;//print server combo list array 

@protected NSString* sLdapQueryCommand;//for LDAP Queries 
@protected NSArray* aLdapQueryArgs; 
@protected NSTask* tskLdapTask; 
@protected NSPipe* pipeLdapTask; 
@protected NSFileHandle* fhLdapTask; 
@protected NSMutableData* mdLdapTask; 

IBOutlet NSComboBox* comboDomain; 
IBOutlet NSComboBox* comboPrinter; 
IBOutlet NSComboBox* comboPrintServer; 
//end of interface globals 

//after collecting the print-server names they are displayed in an according drop-down comboBox 
//as soon as the user selects one of the print-servers, we should start a new query to find all the 
//print-queues on that server and display them in the comboPrinter drop-down list 
//to find the shares/print queues of a windows print-server you need samba and the net -S command like this: 
// net -S yourPrintServerName.yourBaseDomain.com -U yourLdapUser%yourLdapUserPassWord -W adm rpc share -l 
//which dispalays a long list of the shares 

- (IBAction)onSelectDomain:(id)sender 
{ 
    static int indexOfLastItem = 0; //unfortunately we need to compare this because we are called also if the selection did not change! 

    if ([comboDomain indexOfSelectedItem] != indexOfLastItem && ([comboDomain indexOfSelectedItem] != 0)) 
    { 

     indexOfLastItem = [comboDomain indexOfSelectedItem]; //retain this index for next call 

    //the print-servers-list has to be loaded on a per univeristy or domain basis from a file dynamically or from AN LDAP-QUERY 

    //initialize an LDAP-Query-Task or console-command like this one with console output 
    /* 

    ldapsearch -LLL -s sub -D "cn=yourLdapUser,ou=yourOuWithLdapUserAccount,dc=yourDomain,dc=com" -h "yourLdapServer.com" -p 3268 -w "yourLdapUserPassWord" -b "dc=yourBaseDomainToSearchIn,dc=com" "(&(objectcategory=computer)(cn=ps*))" "dn" 

//our print-server names start with ps* and we want the dn as result, wich comes like this: 

    dn: CN=PSyourPrintServerName,CN=Computers,DC=yourBaseDomainToSearchIn,DC=com 

    */ 

    sLdapQueryCommand = [[NSString alloc] initWithString: @"/usr/bin/ldapsearch"]; 


    if ([[comboDomain stringValue] compare: @"firstDomain"] == NSOrderedSame) { 

     aLdapQueryArgs = [NSArray arrayWithObjects: @"-LLL",@"-s", @"sub",@"-D", @"cn=yourLdapUser,ou=yourOuWithLdapUserAccount,dc=yourDomain,dc=com",@"-h", @"yourLdapServer.com",@"-p",@"3268",@"-w",@"yourLdapUserPassWord",@"-b",@"dc=yourFirstDomainToSearchIn,dc=com",@"(&(objectcategory=computer)(cn=ps*))",@"dn",nil]; 
    } 
    else { 
     aLdapQueryArgs = [NSArray arrayWithObjects: @"-LLL",@"-s", @"sub",@"-D", @"cn=yourLdapUser,ou=yourOuWithLdapUserAccount,dc=yourDomain,dc=com",@"-h", @"yourLdapServer.com",@"-p",@"3268",@"-w",@"yourLdapUserPassWord",@"-b",@"dc=yourSecondDomainToSearchIn,dc=com",@"(&(objectcategory=computer)(cn=ps*))",@"dn",nil]; 

    } 


    //prepare and execute ldap-query task 

    tskLdapTask = [[NSTask alloc] init]; 
    pipeLdapTask = [[NSPipe alloc] init];//instead of [NSPipe pipe] 
    [tskLdapTask setStandardOutput: pipeLdapTask];//hope to get the tasks output in this file/pipe 

    //The magic line that keeps your log where it belongs, has to do with NSLog (see https://stackoverflow.com/questions/412562/execute-a-terminal-command-from-a-cocoa-app and here http://www.cocoadev.com/index.pl?NSTask) 
    [tskLdapTask setStandardInput:[NSPipe pipe]]; 

    //fhLdapTask = [[NSFileHandle alloc] init];//would be redundand here, next line seems to do the trick also 
    fhLdapTask = [pipeLdapTask fileHandleForReading]; 
    mdLdapTask = [NSMutableData dataWithCapacity:512];//prepare capturing the pipe buffer which is flushed on read and can overflow, start with 512 Bytes but it is mutable, so grows dynamically later 
    [tskLdapTask setLaunchPath: sLdapQueryCommand]; 
    [tskLdapTask setArguments: aLdapQueryArgs]; 

#ifdef bDoDebug 
    NSLog (@"sLdapQueryCommand: %@\n", sLdapQueryCommand); 
    NSLog (@"aLdapQueryArgs: %@\n", aLdapQueryArgs); 
    NSLog (@"tskLdapTask: %@\n", [tskLdapTask arguments]); 
#endif 

    [tskLdapTask launch]; 

    while ([tskLdapTask isRunning]) { 
     [mdLdapTask appendData: [fhLdapTask readDataToEndOfFile]]; 
    } 
    [tskLdapTask waitUntilExit];//might be redundant here. 

    [mdLdapTask appendData: [fhLdapTask readDataToEndOfFile]];//add another read for safety after process/command stops 

    NSString* sLdapOutput = [[NSString alloc] initWithData: mdLdapTask encoding: NSUTF8StringEncoding];//convert output to something readable, as NSData and NSMutableData are mere byte buffers 

#ifdef bDoDebug 
    NSLog(@"LdapQueryOutput: %@\n", sLdapOutput); 
#endif 

    //Ok now we have the printservers from Active Directory, lets parse the output and show the list to the user in its combo box 
    //output is formatted as this, one printserver per line 
    //dn: CN=PSyourPrintServer,OU=Computers,DC=yourBaseDomainToSearchIn,DC=com 

    //so we have to search for "dn: CN=" to retrieve each printserver's name 
    //unfortunately splitting this up will give us a first line containing only "" empty string, which we can replace with the word "choose" 
    //appearing as first entry in the comboBox 

    aPrintServers = (NSMutableArray*)[sLdapOutput componentsSeparatedByString:@"dn: CN="];//split output into single lines and store it in the NSMutableArray aPrintServers 

#ifdef bDoDebug 
    NSLog(@"aPrintServers: %@\n", aPrintServers); 
#endif 

    if ([[aPrintServers objectAtIndex: 0 ] compare: @"" options: NSLiteralSearch] == NSOrderedSame){ 
     [aPrintServers replaceObjectAtIndex: 0 withObject: slChoose];//replace with localized string "choose" 

#ifdef bDoDebug 
     NSLog(@"aPrintServers: %@\n", aPrintServers); 
#endif 

    } 

//Now comes the tedious part to extract only the print-server-names from the single lines 
    NSRange r; 
    NSString* sTemp; 

    for (int i = 1; i < [aPrintServers count]; i++) {//skip first line with "choose". To get rid of the rest of the line, we must isolate/preserve the print server's name to the delimiting comma and remove all the remaining characters 
     sTemp = [aPrintServers objectAtIndex: i]; 
     sTemp = [sTemp stringByTrimmingCharactersInSet: [NSCharacterSet whitespaceAndNewlineCharacterSet]];//remove newlines and line feeds 

#ifdef bDoDebug 
     NSLog(@"sTemp: %@\n", sTemp); 
#endif 
     r = [sTemp rangeOfString: @","];//now find first comma to remove the whole rest of the line 
     //r.length = [sTemp lengthOfBytesUsingEncoding:NSUTF8StringEncoding]; 
     r.length = [sTemp length] - r.location;//calculate number of chars between first comma found and lenght of string 
#ifdef bDoDebug 
     NSLog(@"range: %i, %i\n", r.location, r.length); 
#endif 

     sTemp = [sTemp stringByReplacingCharactersInRange:r withString: @"" ];//remove rest of line 
#ifdef bDoDebug 
     NSLog(@"sTemp after replace: %@\n", sTemp); 
#endif 

     [aPrintServers replaceObjectAtIndex: i withObject: sTemp];//put back string into array for display in comboBox 

#ifdef bDoDebug 
     NSLog(@"aPrintServer: %@\n", [aPrintServers objectAtIndex: i]); 
#endif 

    } 

    [comboPrintServer removeAllItems];//reset combo box 
    [comboPrintServer addItemsWithObjectValues:aPrintServers]; 
    [comboPrintServer setNumberOfVisibleItems:aPrintServers.count]; 
    [comboPrintServer selectItemAtIndex:0]; 

#ifdef bDoDebug 
    NSLog(@"comboPrintServer reloaded with new values."); 
#endif 


//release memory we used for LdapTask 
    [sLdapQueryCommand release]; 
    [aLdapQueryArgs release]; 
    [sLdapOutput release]; 

    [fhLdapTask release]; 

    [pipeLdapTask release]; 
// [tskLdapTask release];//strangely can not be explicitely released, might be autorelease anyway 
// [mdLdapTask release];//strangely can not be explicitely released, might be autorelease anyway 

    [sTemp release]; 

    } 
} 

Answer 7

He mi ser encontrado caso en el que no fue suficiente para la cadena acaba separado por componentes muchas tareas tales como
1) La clasificación de token en tipos
2) Adición de nuevas fichas
3) separar cuerda entre los cierres personalizados como todas las palabras entre "{" y "}"
Para cualquiera de estos requisitos encontré Parse Kit un salvavidas.

Lo usé para analizar archivos .PGN (nota de juego prtable) con éxito es muy rápido y ligero.

Answer 8

Si usted está mirando para tokenise una cadena en términos de búsqueda preservando al mismo tiempo "frases citadas", aquí es una categoría NSString que respete los diversos tipos de pares de cotización: ""''‘’“”

Uso:

NSArray *terms = [@"This is my \"search phrase\" I want to split" searchTerms]; 
// results in: ["This", "is", "my", "search phrase", "I", "want", "to", "split"] 

Código:

@interface NSString (Search) 
- (NSArray *)searchTerms; 
@end 

@implementation NSString (Search) 

- (NSArray *)searchTerms { 

    // Strip whitespace and setup scanner 
    NSCharacterSet *whitespace = [NSCharacterSet whitespaceAndNewlineCharacterSet]; 
    NSString *searchString = [self stringByTrimmingCharactersInSet:whitespace]; 
    NSScanner *scanner = [NSScanner scannerWithString:searchString]; 
    [scanner setCharactersToBeSkipped:nil]; // we'll handle whitespace ourselves 

    // A few types of quote pairs to check 
    NSDictionary *quotePairs = @{@"\"": @"\"", 
           @"'": @"'", 
           @"\u2018": @"\u2019", 
           @"\u201C": @"\u201D"}; 

    // Scan 
    NSMutableArray *results = [[NSMutableArray alloc] init]; 
    NSString *substring = nil; 
    while (scanner.scanLocation < searchString.length) { 
     // Check for quote at beginning of string 
     unichar unicharacter = [self characterAtIndex:scanner.scanLocation]; 
     NSString *startQuote = [NSString stringWithFormat:@"%C", unicharacter]; 
     NSString *endQuote = [quotePairs objectForKey:startQuote]; 
     if (endQuote != nil) { // if it's a valid start quote we'll have an end quote 
      // Scan quoted phrase into substring (skipping start & end quotes) 
      [scanner scanString:startQuote intoString:nil]; 
      [scanner scanUpToString:endQuote intoString:&substring]; 
      [scanner scanString:endQuote intoString:nil]; 
     } else { 
      // Single word that is non-quoted 
      [scanner scanUpToCharactersFromSet:whitespace intoString:&substring]; 
     } 
     // Process and add the substring to results 
     if (substring) { 
      substring = [substring stringByTrimmingCharactersInSet:whitespace]; 
      if (substring.length) [results addObject:substring]; 
     } 
     // Skip to next word 
     [scanner scanCharactersFromSet:whitespace intoString:nil]; 
    } 

    // Return non-mutable array 
    return results.copy; 

} 

@end 

Answer 9

Si busca para la división lingüística característica de una cadena de (palabras, párrafos, caracteres, frases y líneas), el uso de cadena enumeración:

NSString * string = @" \n word1! word2,%$?'/word3.word4 "; 

[string enumerateSubstringsInRange:NSMakeRange(0, string.length) 
          options:NSStringEnumerationByWords 
         usingBlock: 
^(NSString *substring, NSRange substringRange, NSRange enclosingRange, BOOL *stop) { 
    NSLog(@"Substring: '%@'", substring); 
}]; 

// Logs: 
// Substring: 'word1' 
// Substring: 'word2' 
// Substring: 'word3' 
// Substring: 'word4' 

Esta API funciona con otros idiomas en los espacios no son siempre el delimitador (por ejemplo, Japonés). También usar NSStringEnumerationByComposedCharacterSequences es la forma correcta de enumerar caracteres, ya que muchos caracteres no occidentales tienen más de un byte de longitud.