如何解决使用NSPredicate分析字符串
| 你好！这个问题很长，因此请务必先坐下:) 在代码的某一时刻，我从用户那里得到了一个字符串，然后我对该字符串进行了分析。通过分析，我的意思是遍历每个字符并将其与用户在NSPredicateEditor中设置的谓词相对应。谓词通过以下方式进行编程设置：NSArray* keyPaths = [NSArray arrayWithObjects:
[NSExpression expressionForKeyPath: @\"Character\"],[NSExpression expressionForKeyPath: @\"Character Before\"],[NSExpression expressionForKeyPath: @\"Character After\"],nil];
// -----------------------------------------
NSArray* constants = [NSArray arrayWithObjects:
[NSExpression expressionForConstantValue: @\"Any letter\"],[NSExpression expressionForConstantValue: @\"Letter (uppercase)\"],[NSExpression expressionForConstantValue: @\"Letter (lowercase)\"],[NSExpression expressionForConstantValue: @\"Number\"],[NSExpression expressionForConstantValue: @\"Alphanumerical\"],[NSExpression expressionForConstantValue: @\"Ponctuation Mark\"],nil];
// -----------------------------------------
NSArray* compoundTypes = [NSArray arrayWithObjects:
[NSNumber numberWithInteger: NSNotPredicateType],[NSNumber numberWithInteger: NSAndPredicateType],[NSNumber numberWithInteger: NSOrPredicateType],nil];
// -----------------------------------------
NSArray* operatorsA = [NSArray arrayWithObjects:
[NSNumber numberWithInteger: NSEqualToPredicateOperatorType],[NSNumber numberWithInteger: NSNotEqualToPredicateOperatorType],nil];
NSArray* operatorsB = [NSArray arrayWithObjects:
[NSNumber numberWithInteger: NSInPredicateOperatorType],nil];
// -----------------------------------------
NSPredicateEditorRowTemplate* template1 = [[NSPredicateEditorRowTemplate alloc] initWithLeftExpressions: keyPaths
rightExpressions: constants
modifier: NSDirectPredicateModifier
operators: operatorsA
options: 0];
NSPredicateEditorRowTemplate* template2 = [[NSPredicateEditorRowTemplate alloc] initWithLeftExpressions: keyPaths
rightExpressionAttributeType: NSStringAttributeType
modifier: NSDirectPredicateModifier
operators: operatorsB
options: 0];
NSPredicateEditorRowTemplate* compound = [[NSPredicateEditorRowTemplate alloc] initWithCompoundTypes: compoundTypes];
// -----------------------------------------
NSArray* rowTemplates = [NSArray arrayWithObjects: template1,template2,compound,nil];
[myPredicateEditor setRowTemplates: rowTemplates];
originalString = [string from NSTextView]
for (char in originalString)
bChar = [character before char]
aChar = [character after char]
predicate = [predicate from myPredicateEditor]
// using predicate - problem!
result = [evaluate predicate with:
bChar somehow \'linked\' to keypath \'Character Before\'
char \'linked\' to \'Character\'
aChar \'linked\' to \'Character After\' // These values change,of course
and also:
constant \"All letters\" as \"abc...WXYZ\"
constant \"Numbers\" as \"0123456789\"
etc for all other constants set up // These don\'t
]
if (result) then do something with char,bChar and aChar
#define kPredicateSubstitutionsDict [NSDictionary dictionaryWithObjectsAndKeys: \\
@\"IN \'abcdefghijklmnopqrstuvwxyz\'\",@\"== \\\"Letter (lowercase)\\\"\",\\
@\"IN \'ABCDEFGHIJKLMNOPQRSTUVWXYZ\'\",@\"== \\\"Letter (uppercase)\\\"\",\\
@\"IN \'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ\'\",@\"== \\\"Any letter\\\"\",\\
@\"IN \'1234567890\'\",@\"== \\\"Number\\\"\",\\
@\"IN \'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890\'\",@\"== \\\"Alphanumerical\\\"\",\\
@\"IN \',.;:!?\'\",@\"== \\\"Ponctuation Mark\\\"\",\\
\\
@\"MATCHES \'[^a-z]\'\",@\"!= \\\"Letter (lowercase)\\\"\",\\
@\"MATCHES \'[^A-Z]\'\",@\"!= \\\"Letter (uppercase)\\\"\",\\
@\"MATCHES \'[^a-zA-Z]\'\",@\"!= \\\"Any letter\\\"\",\\
@\"MATCHES \'[^0-9]\'\",@\"!= \\\"Number\\\"\",\\
@\"MATCHES \'[^a-zA-Z0-9]\'\",@\"!= \\\"Alphanumerical\\\"\",\\
@\"MATCHES \'[^,\\.;:!\\?]\'\",@\"!= \\\"Ponctuation Mark\\\"\",\\
\\
nil]
// NSPredicate* predicate is setup in another place
// NSString* originalString is also setup in another place
NSString* predFormat = [predicate predicateFormat];
for (NSString* key in [kPredicateSubstitutionsDict allKeys]) {
prefFormat = [predFormat stringByReplacingOccurrencesOfString: key withString: [kPredicateSubstitutionsDict objectForKey: key]];
}
for (NSInteger i = 0; i < [originalString length]; i++) {
NSString* charString = [originalString substringWithRange: NSMakeRange(i,1)];
NSString* bfString;
NSString* afString;
if (i == 0) {
bfString = @\"\";
}
else {
bfString = [originalString substringWithRange: NSMakeRange(i - 1,1)];
}
if (i == [originalString length] - 1) {
afString = @\"\";
}
else {
afString = [originalString substringWithRange: NSMakeRange(i + 1,1)];
}
predFormat = [predFormat stringByReplacingOccurrencesOfString: @\"Character Before\" withString: [NSString stringWithFormat: @\"\\\"%@\\\"\",bfString]];
predFormat = [predFormat stringByReplacingOccurrencesOfString: @\"Character After\" withString: [NSString stringWithFormat: @\"\\\"%@\\\"\",afString]];
predFormat = [predFormat stringByReplacingOccurrencesOfString: @\"Character\" withString: [NSString stringWithFormat: @\"\\\"%@\\\"\",charString]];
NSPredicate* newPred = [NSPredicate predicateWithFormat: predFormat];
if ([newPred evaluateWithObject: self]) { // self just so I give it something (nothing is actually gotten from self)
// if predicate evaluates to true,then do something exciting!
}
}
解决方法
因此，主要问题是：
您可以构建一个使用不同于用户界面中显示的常量的ѭ3吗？
答：可以。您曾经能够在Interface Builder中进行设置，但是我在Xcode 4中进行设置的尝试并未成功。有可能在IB => Xcode 4合并中删除了该功能。
幸运的是，您可以通过代码来实现。不幸的是，它需要一个“ 3”子类。没有这样的子类，我还没有找到一种方法。
要点是覆盖行模板中的
-templateViews
- (NSArray *)templateViews {
NSArray *views = [super templateViews];
// views[0] is the left-hand popup
// views[1] is the operator popup
// views[2] is the right-hand side (textfield,popup,whatever)
NSPopUpButton *left = [views objectAtIndex:0];
NSArray *items = [left itemArray];
for (NSMenuItem *item in items) {
//the representedObject of the item is the expression that will be used in the predicate
NSExpression *keyPathExpression = [item representedObject];
//we can alter the -title of the menuItem without altering the expression object
if ([[keyPathExpression keyPath] isEqual:@\"before\"]) {
[item setTitle:@\"Character Before\"];
} else if ([[keyPathExpression keyPath] isEqual:@\"after\"]) {
[item setTitle:@\"Character After\"];
}
}
return views;
}
NSPredicateEditor
!=
==
character MATCHES \'[0-9]\'
character MATCHES \'[^0-9]\'
NOT(character MATCHES \'[0-9]\')
MATCHES \'[0-9]\'
NSPredicateEditorRowTemplate
- (void)setVisibleMenuTitlesInPredicate:(NSPredicateEditorRowTemplate *)predicateTemplate
{
NSArray *predicateTemplateViews = [predicateTemplate templateViews];
NSPopUpButton *leftMenu = [predicateTemplateViews objectAtIndex:0];
NSArray *leftMenuList = [leftMenu itemArray];
for (NSMenuItem *menuItem in leftMenuList) {
id keyPathValue = [menuItem representedObject];
if ([[keyPathExpression keyPath] isEqual:@\"before\"]) {
[menuItem setTitle:@\"Character Before\"];
} else if ([[keyPathExpression keyPath] isEqual:@\"after\"]) {
[menuItem setTitle:@\"Character After\"];
}
}
[self setVisibleMenuTitlesInPredicate:predicateTemplateA];
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