antlr4 and international characters - unicode

I have been using antlr4 to parse a German document and so far I have done the following to parse the text that includes German characters:
LETTERS:
[a-zA-Z_\u00DC\u00FC\u00D6\u00F6\u00C4\u00E4\u00DF]; // hex unicodes for ÜüÖöÄäß
what is the best way to describe lingual characters of all languages in Unicode in a way that antlr understands, without specifying each language/character individually? say, the french, Arabic, or Chinese, Japanese characters?
Thank you

The best way is to use character ranges corresponding to the desired Unicode classes. Even then, the result can be a bit clumsy. See this worked example.
The raw data available in the Unicode standard's Appendix tables can be stripped and munged into a usable format with just a bit too much effort. ;)

Related

How to convert punjabi unicode to English Text?

I have records saved in SQL SERVER database in form of punjabi unicode. Now i want to convert these punjabi unicode to English Text. Is there any utility which can help me? Please reply if anyone have solution paid/free. Thanks in advance.
The question is nonsensical -- in the sense that it makes no sense.
Unicode is not a language. It merely provides a mapping from characters (more precisely, glyphs) to a binary code, in such a way that text in a font using Punjabi characters will stay that way when another font is applied. There is no "English" Unicode, and no "Punjabi" Unicode either.
You can only 'translate' from Punjabi to English using translating software. (Given the current state of automatic translation software, you are better off with a human who is fluent in both languages.)
If you wants to change Punjabi Unicode converted into English Text as example
ਨਿੱਕੀ ਕਹਾਣੀ (unicode)
in`kI khwxI (Converted into Gurmukhi Lipi, shows as English ! When you change its font into GurmukhiLipi it shows in punjabi)
You can check my website, previously in UNICODE and now in GURBANI LIPI (I have installed a plugin to convert English Letters as Punjabi)

Romanization of Unicode text

I am looking for a way to transliterate Unicode letter characters from any language into accented Latin letters. The intent is to allow foreigners to gain insight into the pronunciation of names and words written in any non-Latin script.
Examples:
Greek:Romanize("Αλφαβητικός") returns "Alphabētikós" (or "Alfavi̱tikós")
Japanese:Romanize("しんばし") returns "shimbashi" (or "sinbasi")
Russian:Romanize("яйца Фаберже") returns "yaytsa Faberzhe" (or "jajca Faberže")
It should ideally support characters in the following scripts: CJK, Indic, Cyrillic, Semitic, and Greek. It should to be data driven and extensible, using data from either the Unicode Consortium, the USA, the EU or the UN. The code should be open source written in .NET or Java.
Does such a library exist?
The problem is a lot more complex than you think.
Greek, Cyrillic, Indic scripts, Georgian -> trivial, you could program that in an hour
Thai, Japanese Kana -> doable with a bit more effort
Japanese Kanji, Chinese -> these are not alphabets/syllaberies, so you're not in fact transliterating, you're looking up the pronunciation of each symbol in a hopefully large dictionary (EDICT and CCDICT should work), and a lot of times you'll get it wrong unless you're also considering the context, especially in Japanese
Korean -> technically an alphabet, but computers can only handle the composed characters, so you need another large database, I'm not aware of any
Arabic, Hebrew -> these languages don't write down short vowels, so a lot of times your transliteration will be something unreadable like "bytlhm" (Bethlehem). I'm not aware of any large databases that map Arabic or Hebrew words to their pronunciation.
You can use Unidecode Sharp :
[a C#] port from Python Unidecode that itself port from Perl unidecode.
(there are also PHP and Ruby implementations available)
Usage;
using BinaryAnalysis.UnidecodeSharp;
.......................................
string _Greek="Αλφαβητικός";
MessageBox.Show(_Greek.Unidecode());
string _Japan ="しんばし";
MessageBox.Show(_Japan.Unidecode());
string _Russian ="яйца Фаберже";
MessageBox.Show(_Russian.Unidecode());
I hope, it will be good for you.
I am unaware of any open source solution here beyond ICU. If ICU works for you, great. If not, note that I am the CTO of a company that sells a commercial produce for this purpose that can deal with the icky cases like Chinese words, Japanese multiple reading, and Arabic incomplete orthography.
The Unicode Common Locale Data Repository has some transliteration mappings you could use.

Simplified Chinese Unicode table

Where can I find a Unicode table showing only the simplified Chinese characters?
I have searched everywhere but cannot find anything.
UPDATE :
I have found that there is another encoding called GB 2312 -
http://en.wikipedia.org/wiki/GB_2312
- which contains only simplified characters.
Surely I can use this to get what I need?
I have also found this file which maps GB2312 to Unicode -
http://cpansearch.perl.org/src/GUS/Unicode-UTF8simple-1.06/gb2312.txt
- but I'm not sure if it's accurate or not.
If that table isn't correct maybe someone could point me to one that is, or maybe just a table of the GB2312 characters and some way to convert them?
UPDATE 2 :
This site also provides a GB/Unicode table and even a Java program to generate a file
with all the GB characters as well as the Unicode equivalents :
http://www.herongyang.com/gb2312/
The Unihan database contains this information in the file Unihan_Variants.txt. For example, a pair of traditional/simplified characters are:
U+673A kTraditionalVariant U+6A5F
U+6A5F kSimplifiedVariant U+673A
In the above case, U+6A5F is 機, the traditional form of 机 (U+673A).
Another approach is to use the CC-CEDICT project, which publishes a dictionary of Chinese characters and compounds (both traditional and simplified). Each entry looks something like:
宕機 宕机 [dang4 ji1] /to crash (of a computer)/Taiwanese term for 當機|当机[dang4 ji1]/
The first column is traditional characters, and the second column is simplified.
To get all the simplified characters, read this text file and make a list of every character that appears in the second column. Note that some characters may not appear by themselves (only in compounds), so it is not sufficient to look at single-character entries.
The OP doesn't indicate which language they're using, but if you're using Ruby, I've written a small library that can distinguish between simplified and traditional Chinese (plus Korean and Japanese as a bonus). As suggested in Greg's answer, it relies on a distilled version of Unihan_Variants.txt to figure out which chars are exclusively simplified and which are exclusively traditional.
https://github.com/jpatokal/script_detector
Sample:
p string
=> "我的氣墊船充滿了鱔魚."
> string.chinese?
=> true
> string.traditional_chinese?
=> true
> string.simplified_chinese?
=> false
But as the Unicode FAQ duly warns, this requires sizable fragments of text to work reliably, and will give misleading results for short strings. Consider the Japanese for Tokyo:
p string
=> "東京"
> string.chinese?
=> true
> string.traditional_chinese?
=> true
> string.japanese?
=> false
Since both characters happen to also be valid traditional Chinese, and there are no exclusively Japanese characters, it's not recognized correctly.
I'm not sure if that's easily done. The Han ideographs are unified in Unicode, so it's not immediately obvious how to do it. But the Unihan database (http://www.unicode.org/charts/unihan.html) might have the data you need.
Here is a regex of all simplified Chinese characters I made. For some reason Stackoverflow is complaining, so it's linked in a pastebin below.
https://pastebin.com/xw4p7RVJ
You'll notice that this list features ranges rather than each individual character, but also that these are utf-8 characters, not escaped representations. It's served me well in one iteration or another since around 2010. Hopefully everyone else can make some use of it now.
If you don't want the simplified chars (I can't imagine why, it's not come up once in 9 years), iterate over all the chars from ['一-龥'] and try to build a new list. Or run two regex's, one to check it is Chinese, but is not simplified Chinese
According to wikipedia simplified Chinese v. traditional, kanji, or other formats is left up to the font rendering in many cases. So while you could have a selection of simplified Chinese codepoints, this list would not be at all complete since many characters are no longer distinct.
I don't believe that there's a table with only simplified code points. I think they're all lumped together in the CJK range of 0x4E00 through 0x9FFF

Detect if character is simplified or traditional Chinese character

I found this question which gives me the ability to check if a string contains a Chinese character. I'm not sure if the unicode ranges are correct but they seem to return false for Japanese and Korean and true for Chinese.
What it doesn't do is tell if the character is traditional or simplified Chinese. How would you go about finding this out?
update
Q: How can I recognize from the 32 bit value of a Unicode character if this is a Chinese, Korean or Japanese character?
http://unicode.org/faq/han_cjk.html
Their argument that the characters regardless of their shape have the same meaning and therefore should be represented by the same code. Well, it's not meaningless to me because I am analyzing individual characters which doesn't work with their solution:
A better solution is to look at the text as a whole: if there's a fair amount of kana, it's probably Japanese, and if there's a fair amount of hangul, it's probably Korean.
As already stated, you can't reliably detect the script style from a single character, but it is possible for a sufficiently long sample of text. See https://github.com/jpatokal/script_detector for a Ruby gem that does the job, and Simplified Chinese Unicode table for a general discussion.
It is possible for some characters. The Traditional and Simplified character sets overlap, so you have basically three sets of characters:
Characters that are traditional only.
Characters that are simplified only.
Characters that have been left untouched, and are available in both.
Take the character 面 for instance. It belongs both to #2 and #3... As a simplified character, it stands for 面 and 麵, face and noodles. Whereas 麵 is a traditional character only. So in the Unihan database, 麵 has a kSimplifiedVariant, which points to 面. So you can deduct that it is a traditional character only.
But 面 also has a kTraditionalVariant, which points to 麵. This is where the system breaks: if you use this data to deduct that 面 is a simplified character only, you'd be wrong...
On the other hand, 韩 has a kTraditionalVariant, pointing to 韓, and these two are a "real" Simplified/Traditional pair. But nothing in the Unihan database differentiates cases like 韓/韩 from cases like 麵/面.
As I think you've discovered, you can't. Simplified and traditional are just two styles of writing the same characters - it's like the difference between Roman and Gothic script for European languages.

wxWidgets and Unicode

i want to use korean translations under in my - quite large - wxwidgets application. The application uses the wxwidgets translation framework, which is based on gettext.
I have working translations for french, german and russian. I want to go unicode anyway, but my first question is:
does my application need unicode support to display korean and japanese languages?
If so, - just for interest - why does russian work without, since they have a cyrillic letterset?
I have thousands of string literals. Do i have to prepend each and every one of them with 'L' ? ( wxString foo("foo") --> wxString foo(L"foo") )
if so, did someone build a regex or sed or perl script to do this in ca. 500 .cpp files ? ( pleeze! =) )
Will this change in wxWidgets 3.0?
Unicode question general: i use these string literals in many descriptive and many technical ways .. as displayed text as well as parts of GLSL shaders as well as XML. These APIs have char* / const char* as function arguments, so my internal wxString representation should not matter in these areas. Theory and practice: is this true? Some experiences to share, anyone?
I do some text processing ( comparing, string finding etc ) - are there any logical differences in unicode vs. ansi?
Is there any remarkeable performance impact in using Unicode?
Thank you!
Wendy
Addressing some of your questions…
does my application need unicode support to display korean and japanese languages?
If so, - just for interest - why does russian work without, since they have a cyrillic letterset?
Russian fits in a single-byte charset, just like western European languages (though it is a different charset). Korean and Japanese (and Chinese) don't. There are many workarounds for this, but the most elegant I know of to date is to use Unicode so that you don't need to rebuild your application for each locale; just change its message catalog.
Unicode question general: i use these string literals in many descriptive and many technical ways .. as displayed text as well as parts of GLSL shaders as well as XML. These APIs have char* / const char* as function arguments, so my internal wxString representation should not matter in these areas. Theory and practice: is this true? Some experiences to share, anyone?
Only strings that are going to be shown to (non-technical) users need to be localized, so they're the only ones that have to be in Unicode. The most common approach is to use UTF-8 (which is a particular way of encoding Unicode) as that means that ASCII strings – the most common type passed around inside programs – are exactly the same, which simplifies things a lot. The down-side is that you no longer have cheap indexing into the string as not all characters are the same number of bytes long. That can be anything from a non-issue to a right royal hindering PITA, depending on what the program is doing.
I do some text processing ( comparing, string finding etc ) - are there any logical differences in unicode vs. ansi?
Comparisons work fine, as does simple string finding. Other operations (e.g., getting the 20th character of a string, or working out how many characters into a string you've found a substring) are nasty because you've not got constant character widths. The nastiness can be mitigated by using wide characters, but they're less nice to use for external data (they introduce potential problems with endianness unless you go into working with byte-order marks, and that's another matter right there).
Is there any remarkeable performance impact in using Unicode?
Depends on exactly what you do. With UTF-8, if you're mostly dealing with ASCII text in reality then you get very little in the way of performance problems for most operations. With wide characters, you take more memory for every character, which naturally has performance implications (but which might acceptable because it does mean you've got constant-time indexing).
There's a korean .po file on http://www.wxwidgets.org/about/i18n.php for wxWidget's own strings. If your application displays wxWidget's own strings correctly when using that file, then it does not need Unicode support to display Korean and Japanese languages.
ISO-8859-5 is an 8 bit character set with Cyrillic letters.
Only if 1. does not yield the correct result. But if you want to translate the string, you should have used _().
I don't know.
wxWidgets 3.0 will not have separate Unicode- and ANSI-builds. 2.9.1 doesn't have, either.
It depends on how you use the arguments. C- and C++-functions usually operate on the representation of strings and are unaware of any particular character encoding. Particularly what you perceive to be a character and what the program considers a character might be different things.
See 6.
I do not know, but many toolkits use UTF-16 or UTF-32 instead of UTF-8 because these schemes are simpler. It's a size-speed tradeoff.
1.does my application need unicode support to display korean and japanese
languages?
Thanks to Oswald, i found out that you can have a korean translation without using unicode in your wxwidgets application. Change ( under windows, at least ) settings for non-unicode aware programs. But i still have to check out if this is enough for a whole application.
3.I have thousands of string literals. Do i have to prepend each
and every one of them with 'L' ? (
wxString foo("foo") --> wxString
foo(L"foo") )
If you have to use unicode with wxwidgets prior to 3.0, you have to. But do not use 'L' under wxwidgets, use wxT("foo")
4.if so, did someone build a regex or sed or perl script to do this in ca. 500 .cpp files ?
I did, at least a search and replace under Visual Studio:
Search: {"([^"]*)"}
Replace: wxT(\1)
But be careful! Will replace all string literals, #include "file.h" with #include wxT("file.h")
Will this change in wxWidgets 3.0?
Yes. See answer/quote above.