objective-c - NSRegularExpression enumerateMatchesInString :options:range:usingBlock: giving a null result?

我在解析器中使用了一个正则表达式，但是，它似乎给了很多结果，这是我的代码:
正则表达式:

self.seatSelectRegex = [NSRegularExpression regularExpressionWithPattern:@"Seat ([0-9]{1,2}): (.*) \\([$£€]?([0-9.]+) in chips\\).*$" options:NSRegularExpressionAnchorsMatchLines error:&error];

代码:

NSMutableDictionary *players = [[NSMutableDictionary alloc] init];
[self.seatSelectRegex enumerateMatchesInString:input options:NSMatchingCompleted range:NSMakeRange(0, input.length) usingBlock:
 ^(NSTextCheckingResult *result, NSMatchingFlags flags, BOOL *stop)
{

    NSLog(@"%lu", result.range.length);
    Player *p = [[Player alloc] init];

    p.name = [input substringWithRange:[result rangeAtIndex:2]];
    p.seatNumber = [input substringWithRange:[result rangeAtIndex:1]].intValue;
    p.stack = [input substringWithRange:[result rangeAtIndex:3]].doubleValue;

    [players setValue:p forKey:p.name];
}];

我期望输入得到3个结果，但是得到4个，其中最后一个结果的范围是location = 0和length = 0(前三个都是正确的)。这是常见现象吗？我应该只是检查范围的位置和长度，还是在某处出现错误？

对于它的值(value)，这是我的投入:

PokerStars Hand #81669312371:  Hold'em No Limit ($0.01/$0.02 USD) - 2012/06/08 16:57:33 CET [2012/06/08 10:57:33 ET]
Table 'Icarus III' 6-max Seat #2 is the button
Seat 2: SanderDecler ($2 in chips)
Seat 3: ehrli87 ($0.90 in chips)
Seat 4: umar.11 ($1.60 in chips)
ehrli87: posts small blind $0.01
umar.11: posts big blind $0.02
*** HOLE CARDS ***
Dealt to SanderDecler [Kh 7d]
SanderDecler: raises $0.04 to $0.06
ehrli87: folds
umar.11: calls $0.04
*** FLOP *** [Jc Tc Jh]
umar.11: checks
SanderDecler: bets $0.08
umar.11: raises $0.24 to $0.32
SanderDecler: folds
Uncalled bet ($0.24) returned to umar.11
umar.11 collected $0.28 from pot
*** SUMMARY ***
Total pot $0.29 | Rake $0.01
Board [Jc Tc Jh]
Seat 2: SanderDecler (button) folded on the Flop
Seat 3: ehrli87 (small blind) folded before Flop
Seat 4: umar.11 (big blind) collected ($0.28)

最佳答案

这是因为您将NSMatchingReportCompletion选项与enumerateMatchesInString:options:range:usingBlock:结合使用。从Apples documentation:



您之所以将最后一个块调用视为位置和长度设置为0的范围的原因是因为您向nil发送消息，该消息将返回nil(整数0)。

关于objective-c - NSRegularExpression enumerateMatchesInString :options:range:usingBlock: giving a null result?，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/10961779/