In my current implementation of a UISearchBarController I'm using [NSString compare:] inside the filterContentForSearchText:scope: delegate method to return relevant objects based on their name property to the results UITableView as you start typing.
So far this works great in English and Korean, but what I'd like to be able to do is search within NSString's defined character clusters. This is only applicable for a handfull of languages, of which Korean is one.
In English, compare: returns new results after every letter you enter, but in Korean the results are generated once you complete a recognized grapheme cluster. I would like to be able to search through my Korean objects name property via the individual elements that make up a syllable.
Can anyone shed any light on how to approach this? I'm sure it has something to do with searching through UTF16 characters manually, or by utilising a lower level class.
Cheers!
Here is a specific example that's just not working:
`NSString *string1 = #"이";
`NSString *string2 = #"ㅣ";
NSRange resultRange = [[string1 decomposedStringWithCanonicalMapping] rangeOfString: [string2 decomposedStringWithCanonicalMapping] options:(NSLiteralSearch)];
The result is always NSNotFound, with or without decomposedStringWithCanonicalMapping.
Any ideas?
I'm no expert, but I think you're very unlikely to find a clean solution for what you want. There doesn't seem to be any relationship between a Korean character's Unicode value and the graphemes that it's made up of.
e.g. "이" is \uc774 and "ㅣ" is \u3163. From the perspective of the NSString, they're just two different characters with no specific relationship to each other.
I suspect that you will have to find or create an explicit mapping between characters and their graphemes, and then write your own search function that consults this mapping.
This very long page on Unicode Korean can help you, if it comes to that. It has a table of all the characters which suggests some structured relation between the way characters are numbered and their components.
If you use compare:options with NSLiteralString, it should compare character by character, that is, the Unicode code points, regardless of the grapheme. The default behavior of compare: is to use no options. You could use - decomposedStringWithCanonicalMapping to get the Unicode bytes of the input string, but I'm not sure how that would interact with compare:.
Related
Subject says it all. Been looking for an answer, but cannot seem to find it.
I am writing a web app that will store data in a database and also have language files translated into a wide variety of character sets. At various moments, the text will be presented. I want to control presentation such as spurious blank spaces at the beginning and end of strings. Also I want to ensure some letters are upper or lower case.
My question is: what happens in upper/lower case functions when the character set only has one case?
EDIT Sub question: Are there any unexpected side effects to be aware of?
My guess is that you simply get back the one and only character.
EDIT - Added Description
The main reason for asking this question is that I am writing a webapp that will be distributed and run on machines in remote areas with little or no chance to fix "on-the-spot" bugs. It's not a complicated webapp, but will run with many different language char sets. I want to be certain of my footing before releasing the server.
First of all the upper() and lower() method in python can be applied to Hindi, Amharric and non-letter character sets.
For instance will the upper() method converts the lowercase characters if an equivalent uppercase of this char exists. If not, then not.
Or better said, if there is nothing to convert, it stays the same.
Where can I get the complete list of all unicode characters that doesn't behave as simple characters. Examples: character 0x0363 (won't be printed without another one before), character 0x0084 (does weird things when printed). I need just a raw list of such unusual characters to replace them with something harmless to avoid unwanted output effects. Regular characters (those who not in this list) should use exactly one character place when printed (= cursor moved +1 to the right), should not depend on previous or next characters, and should not affect printing style in any way.
Edit because of multiple comments:
I have some unicode string, usually consists of "usual" characters like 0x20-0x7E or cyrillic letters. Also, there are a lot of other unicode characters that are usual and may be safely assumed as having strlen() = 1. The string is printed on the terminal and I should know the resulting position of the cursor. I don't want to use some complex and non-stable libraries to do that, i want to have simplest possible logic to do that. Every problematic character may be replaced with U+0xFFFD or something like "<U+0363>" (ASCII string with its index instead of character itself). I want to have a list of "possibly-problematic" characters to replace. It is acceptable to have some non-problematic characters in this list too, but not much.
There is no simple algorithm for this. You'll likely need a complex, but extremely stable library: libicu, or something based on it. Basically every other library that does this kind of work is based on libicu, which is maintained by the Unicode organization.
If you don't want to use the official library (or something based on their library), you'll need to parse the Unicode Character Database yourself. In particular, you need to look at Character Properties, and parse the files in the UCD.
I believe you're asking for Bidi_Class (i.e. "direction") to be Left_To_Right, Canonical_Combining_Class to be Not_Reordered, and Joining_Type to be Non_Joining.
You probably also want to check the General_Category and avoid M* (Marks) and C* (Other).
This should work for some Emoji, but this whole approach will break a lot of emoji that look simple and are not. Most famously: ❤️, which is two "characters," not one. You may want to filter out Emoji. As a simple starting point, you may want to restrict yourself to the Basic Multilingual Plane (BMP), which are code points 0000-FFFF. Anything above this range is, almost by definition, rare or unusual. The BMP does include some emoji, but most emoji (and all new emoji) are outside the range.
Remember that the glyphs for single characters can still have radically different widths, even in nominally fixed-width fonts. For example, 𒈙 (U+12219 CUNEIFORM SIGN LUGAL OPPOSING LUGAL) is a completely "normal" character in the way you're describing. It is left-to-right. It doesn't depend on or influence characters around it (it's non-combining and non-joining). Its "length in characters" is 1. Its glyph is also extremely wide in most fonts and breaks a lot of layout. I don't know anything in the Unicode database that would warn you of this, since "glyph width" is entirely a function of fonts, not characters, and Unicode explicitly does not consider fonts. (That said, most of the most problematic characters are outside the BMP. Probably the most common exception is DŽ, but many fixed-width fonts have a narrow glyph for it: DŽ.)
Let's write some cuneiform in a fixed-width font.
Normally, every character should line up with a character above.
Here: 𒈙. See how these characters don't align correctly?
Not only is it a very wide glyph, but its width is not even a multiple.
At least not in my font (Mac Safari 15.0).
But DŽ is ok.
Also remember that there are multiple ways to encode the same "character." For example, é can be a "simple" character (U+00E9), or it can be two characters (U+0065, U+0301). So in some cases é may print in your scheme, and in others it won't. I suspect this is fine for your problem, but if it isn't, you're going to need to apply a normalization form (likely NFC).
I'm trying to gather a Unicode list of all the 'o' like shapes in the Hindi character-set. In fact, a list of any characters (in any language) that makes uses of separate characters to indicate an accent would be better.
I intend to use this unicode-list in a RegExp.
I been trying to edit a list of character-ranges by outputting them in an Input TextField, but editing this text causes weird issues (the keyboard-cursor isn't place on the correct character, selections suddenly dissappear / incorrectly warps... in other words... HINDI HELL!)
I've tried this with Notepad++ too, but although it was more responsive, it eventually crapped out on me like it did in the Flash Player textfield. This seems to occur especially while removing the [] block (nulls?) characters. Some of them trigger odd behaviors.
Anyways, all I want is a list of the accents.
An example of a few are in the image below (but I would need ALL accents):
Thanks!
You can find pdf's containing lists of unicode ranges, grouped by language, here: http://unicode.org/charts/
For Hindi, you probably want Devanagari or Devanagari Extended.
Here is the character class for Devanagari combining marks:
[\u901\u902\u903\u93c\u93e\u93f\u940\u941\u942\u943
\u944\u945\u946\u947\u948\u949\u94a\u94b\u94c\u94d
\u951\u952\u953\u954\u962\u963]
This is only the basic Devanagari block (not Devanagari Extended).
If you want the complete set (for all languages), you can do it problematically.
You start from the Unicode date file at ftp://ftp.unicode.org/Public/6.1.0/ucd/UnicodeData.txt, described by TR-44 (http://unicode.org/reports/tr44/#Property_Definitions)
You can use the Canonical_Combining_Class field (see at http://unicode.org/reports/tr44/#Canonical_Combining_Class_Values) to filter the exact characters you want.
Can't be more precise, because "accent" a bit vague :-)
You might even have to also look at General_Category to get the filter right (and exclude certain marks, or symbols, or punctuation).
And a script doing this would definitely be better than trying to mess with text editors.
One of the characteristics of combining characters is that they combine :-)
So you might get all kind of puzzling results (like this: http://www.siao2.com/2006/02/17/533929.aspx :-)
I'm trying to implement a word count function for my app that uses UITextView.
There's a space between two words in English, so it's really easy to count the number of words in an English sentence.
The problem occurs with Chinese and Japanese word counting because usually, there's no any space in the entire sentence.
I checked with three different text editors in iPad that have a word count feature and compare them with MS Words.
For example, here's a series of Japanese characters meaning the world's idea: 世界(the world)の('s)アイデア(idea)
世界のアイデア
1) Pages for iPad and MS Words count each character as one word, so it contains 7 words.
2) iPad text editor P*** counts the entire as one word --> They just used space to separate words.
3) iPad text editor i*** counts them as three words --> I believe they used CFStringTokenizer with kCFStringTokenizerUnitWord because I could get the same result)
I've researched on the Internet, and Pages and MS Words' word counting seems to be correct because each Chinese character has a meaning.
I couldn't find any class that counts the words like Pages or MS Words, and it would be very hard to implement it from scratch because besides Japanese and Chinese, iPad supports a lot of different foreign languages.
I think CFStringTokenizer with kCFStringTokenizerUnitWord is the best option though.
Is there a way to count words in NSString like Pages and MSWords?
Thank you
I recommend keep using CFStringTokenizer. Because it's platform feature, so will be upgraded by platform upgrade. And many people in Apple are working hardly to reflect real cultural difference. Which are hard to know for regular developers.
This is hard because this is not a programming problem essentially. This is a human cultural linguistic problem. You need a human language specialist for each culture. For Japanese, you need Japanese culture specialist. However, I don't think Japanese people needs word count feature seriously, because as I heard, the concept of word itself is not so important in the Japanese culture. You should define concept of word first.
And I can't understand why you want to force concept of word count into the character count. The Kanji word that you instanced. This is equal with counting universe as 2 words by splitting into uni + verse by meaning. Not even a logic. Splitting word by it's meaning is sometimes completely wrong and useless by the definition of word. Because definition of word itself are different by the cultures. In my language Korean, word is just a formal unit, not a meaning unit. The idea that each word is matching to each meaning is right only in roman character cultures.
Just give another feature like character counting for the users in east-asia if you think need it. And counting character in unicode string is so easy with -[NSString length] method.
I'm a Korean speaker, (so maybe out of your case :) and in many cases we count characters instead of words. In fact, I never saw people counting words in my whole life. I laughed at word counting feature on MS word because I guessed nobody would use it. (However now I know it's important in roman character cultures.) I have used word counting feature only once to know it works really :) I believe this is similar in Chinese or Japanese. Maybe Japanese users use the word counting because their basic alphabet is similar with roman characters which have no concept of composition. However they're using Kanji heavily which are completely compositing, character-centric system.
If you make word counting feature works greatly on those languages (which are using by people even does not feel any needs to split sentences into smaller formal units!), it's hard to imagine someone who using it. And without linguistic specialist, the feature should not correct.
This is a really hard problem if your string doesn't contain tokens identifying word breaks (like spaces). One way I know derived from attempting to solve anagrams is this:
At the start of the string you start with one character. Is it a word? It could be a word like "A" but it could also be a part of a word like "AN" or "ANALOG". So the decision about what is a word has to be made considering all of the string. You would consider the next characters to see if you can make another word starting with the first character following the first word you think you might have found. If you decide the word is "A" and you are left with "NALOG" then you will soon find that there are no more words to be found. When you start finding words in the dictionary (see below) then you know you are making the right choices about where to break the words. When you stop finding words you know you have made a wrong choice and you need to backtrack.
A big part of this is having dictionaries sufficient to contain any word you might encounter. The English resource would be TWL06 or SOWPODS or other scrabble dictionaries, containing many obscure words. You need a lot of memory to do this because if you check the words against a simple array containing all of the possible words your program will run incredibly slow. If you parse your dictionary, persist it as a plist and recreate the dictionary your checking will be quick enough but it will require a lot more space on disk and more space in memory. One of these big scrabble dictionaries can expand to about 10MB with the actual words as keys and a simple NSNumber as a placeholder for value - you don't care what the value is, just that the key exists in the dictionary, which tells you that the word is recognised as valid.
If you maintain an array as you count you get to do [array count] in a triumphal manner as you add the last word containing the last characters to it, but you also have an easy way of backtracking. If at some point you stop finding valid words you can pop the lastObject off the array and replace it at the start of the string, then start looking for alternative words. If that fails to get you back on the right track pop another word.
I would proceed by experimentation, looking for a potential three words ahead as you parse the string - when you have identified three potential words, take the first away, store it in the array and look for another word. If you find it is too slow to do it this way and you are getting OK results considering only two words ahead, drop it to two. If you find you are running up too many dead ends with your word division strategy then increase the number of words ahead you consider.
Another way would be to employ natural language rules - for example "A" and "NALOG" might look OK because a consonant follows "A", but "A" and "ARDVARK" would be ruled out because it would be correct for a word beginning in a vowel to follow "AN", not "A". This can get as complicated as you like to make it - I don't know if this gets simpler in Japanese or not but there are certainly common verb endings like "ma su".
(edit: started a bounty, I'd like to know the very best way to do this if my way isn't it.)
If you are using iOS 4, you can do something like
__block int count = 0;
[string enumerateSubstringsInRange:range
options:NSStringEnumerationByWords
usingBlock:^(NSString *word,
NSRange wordRange,
NSRange enclosingRange,
BOOL *stop)
{
count++;
}
];
More information in the NSString class reference.
There is also WWDC 2010 session, number 110, about advanced text handling, that explains this, around minute 10 or so.
I think CFStringTokenizer with kCFStringTokenizerUnitWord is the best option though.
That's right, you have to iterate through text and simply count number of word tokens encontered on the way.
Not a native chinese/japanese speaker, but here's my 2cents.
Each chinese character does have a meaning, but concept of a word is combination of letters/characters to represent an idea, isn't it?
In that sense, there's probably 3 words in "sekai no aidia" (or 2 if you don't count particles like NO/GA/DE/WA, etc). Same as english - "world's idea" is two words, while "idea of world" is 3, and let's forget about the required 'the' hehe.
That given, counting word is not as useful in non-roman language in my opinion, similar to what Eonil mentioned. It's probably better to count number of characters for those languages.. Check around with Chinese/Japanese native speakers and see what they think.
If I were to do it, I would tokenize the string with spaces and particles (at least for japanese, korean) and count tokens. Not sure about chinese..
With Japanese you can create a grammar parser and I think it is the same with Chinese. However, that is easier said than done because natural language tends to have many exceptions, but it is not impossible.
Please note it won't really be efficient since you have to parse each sentence before being able to count the words.
I would recommend the use of a parser compiler rather than building one yourself as well to start at least you can concentrate on doing the grammar than creating the parser yourself. It's not efficient, but it should get the job done.
Also have a fallback algorithm in case your grammar didn't parse the input correctly (perhaps the input really didn't make sense to begin with) you can use the length of the string to make it easier on you.
If you build it, there could be a market opportunity for you to use it as a natural language Domain Specific Language for Japanese/Chinese business rules as well.
Just use the length method:
[#"世界のアイデア" length]; // is 7
That being said, as a Japanese speaker, I think 3 is the right answer.
i have the following problem sometimes my openURL-Dialog works perfectly, then i looked at the variable from the url and that is the variable:
www.brehm-gmbh.de
but some other times there are some crazy elements at the end of the variable like this:
www.adamczyk-fenster.de%E2%80%8E
i get this pages from an .asc file and both are in this file normal without this elements,
what can i do to solve this problem?
thank you all for helping beforehand
From Wikipedia:
The left-to-right mark (LRM) is a
control character or non-printing
character, used in the computerized
typesetting of bi-directional text,
containing mixed left-to-right scripts
(such as English and Russian) and
right-to-left scripts (such as Arabic
and Hebrew). It is used to change the
way adjacent characters are grouped
with respect to text direction.
You're getting this because (1) you've got non-English URLs, are composing URLs from non-English strings or you have some other non-English elements and the string encoding is attempting to compensate or (2) it's garbarge being interpreted as an encoding (unlikely if it is consistant.)
Call -[NSString localizedNameOfStringEncoding] on the string before you use it see what encoding it is using. You probably need to explicitly establish an encoding when you read in the strings before you put them in the NSURL.