在objective-C中解析以@和＃开头的字符串 [英] parsing string starting with @ and # in objective-C

问题描述

所以我试图解析一个具有以下格式的字符串：

So I am trying to parse a string that has the following format:

或者，它也可以用空格分隔：

or, it can also be separated by spaces:

以下是我现在的表现：

- (void) parseTagsInComment:(NSString *) comment
{
    if ([comment length] > 0){
        NSArray * stringArray = [comment componentsSeparatedByString:@" "];
        for (NSString * word in stringArray){

        }
    }
}

我已经通过空间工作分离了组件，但如果它没有空间怎么办...如何迭代这些单词？我正在考虑使用正则表达式..但我不知道如何在Objective-C中编写这样的正则表达式。对于这两种情况的正则表达式有什么想法吗？

I've got the components separated by space working, but what if it has no space.. how do I iterate through these words? I was thinking of using regex.. but I have no idea on how to write such regex in objective-C. Any idea, for a regex that would cover both of these cases?

这是我的第一次尝试：

NSError * error;
    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"(@|#)\\S+" options:NSRegularExpressionCaseInsensitive error:&error];

    NSArray* wordArray = [regex matchesInString:comment 
                                      options:0 range:NSMakeRange(0, [comment length])];

    for (NSString * word in wordArray){

    }

哪个不起作用..我认为我的正则表达式是错误的。

Which doesn't work.. I think my regex is wrong.

推荐答案

这是一种方法它使用NSScanner将分隔的字符串和它们的范围的字符串表示形式放入一个数组中（这假设您的原始字符串以＃开头 - 如果它没有并且您需要它，那么只需将哈希添加到字符串中在开始时。）

Here is a way to do it using NSScanner that puts the separated strings and a string representation of their ranges into an array (this assumes that your original string started with a # -- if it doesn't and you need it to, then just prepend the hash to the string at the start).

NSMutableArray *array = [NSMutableArray array];
    NSString *str = @"#baz@marroon#red#blue #big@cat#dog";
    NSScanner *scanner = [NSScanner scannerWithString:str];
    NSCharacterSet *searchSet = [NSCharacterSet characterSetWithCharactersInString:@"#@"];
    NSString *outputString;

    while (![scanner isAtEnd]) {
        [scanner scanUpToCharactersFromSet:searchSet intoString:nil];
        [scanner scanCharactersFromSet:searchSet intoString:&outputString];
        NSString *symbol = [outputString copy];
        [scanner scanUpToCharactersFromSet:searchSet intoString:&outputString];
        NSString *wholePiece = [[symbol stringByAppendingString:outputString]stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
        NSString *rangeString = NSStringFromRange([str rangeOfString:wholePiece]);
        [array addObject:wholePiece];
        [array addObject:rangeString];
    }
    NSLog(@"%@",array);

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