如何从 Xcode 建议之类的列表中搜索（谓词）内容？

Question

我想每个人都会注意到 XCode 建议列表。查看此屏幕截图

As per Apple document doesn't provide what expected ouptut.

NSPredicate *inPredicate = [NSPredicate predicateWithFormat: @"attribute CONTAINS[cd] %@", aCollection];

仅提供连续搜索文本。

这可能吗，如何搜索这样的内容？

Answer 1

一个可能的解决方案是为此使用正则表达式。我们只需要在每个字母之间（以及字符串前后）插入 .*，这意味着 "any character (except for line terminators)"。似乎这就是 XCode 完成时用于搜索的内容。

NSMutableArray *letters = [[NSMutableArray alloc] init];
[searchString enumerateSubstringsInRange:NSMakeRange(0, [searchString length])
                                 options:NSStringEnumerationByComposedCharacterSequences
                              usingBlock:^(NSString * _Nullable substring, NSRange substringRange, NSRange enclosingRange, BOOL * _Nonnull stop) {
    [letters addObject:substring];
}];
NSMutableString *pattern = [[NSMutableString alloc] initWithString:@".*"];
[pattern appendString:[letters componentsJoinedByString:@".*"]];
[pattern appendString:@".*"];
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF.%K MATCHES[C] %@", keyToFilter, pattern];

要播放的示例，请在之前插入：

NSString *keyToFilter = @"attribute";
NSArray *array = @[@{keyToFilter:@"UITextField"}, @{keyToFilter:@"nsarray"}, @{keyToFilter:@"uitf"}];
NSString *searchString = @"uitf";

紧接着：

NSArray *filtered = [array filteredArrayUsingPredicate:predicate];
NSLog(@"SearchString: %@\nFiltered: %@", searchString, ([filtered count]?[filtered valueForKey:keyToFilter]:@"NO RESULT"));

输出：

$>SearchString: uitf
Filtered: (
    UITextField,
    uitf
)

构造字母数组的代码来自here。可以使用不同的解决方案来创建 pattern，它可能不是最好的，但它是可行的。

奖金：

为了好玩（我对如何做很感兴趣），一种可能的方法来为列表着色（我制作了一个 NSAttributedString 的数组）以适应（未完全测试或没有错误）：

NSMutableArray *filteredColored = [[NSMutableArray alloc] init];
for (NSDictionary *aDict in filtered) //or for (MyObjectClass *myObject in filtered)
{
    NSString *aFilteredValue = aDict[keyToFilter]; //or NSString *aFilteredValue = [myObject attribute]
    NSMutableAttributedString *attr = [[NSMutableAttributedString alloc] initWithString:aFilteredValue attributes:@{}];
    NSInteger currentIndex = 0;
    for (NSString *aLetter in letters)
    {
        NSRange rangeFound = [aFilteredValue rangeOfString:aLetter
                                                   options:NSCaseInsensitiveSearch
                                                     range:NSMakeRange(currentIndex, [aFilteredValue length]-currentIndex)];
        if (rangeFound.location != NSNotFound)
        {
            currentIndex = rangeFound.location+rangeFound.length;
            [attr addAttribute:NSBackgroundColorAttributeName value:[UIColor yellowColor] range:rangeFound];
        }
    }
    [filteredColored addObject:attr];
}

如何从 Xcode 建议之类的列表中搜索（谓词）内容？

How to search(Predicate) content from list like Xcode suggestion?

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search-suggestion