27th Internationalization and Unicode ConferenceBerlin, Germany, April 2005 ICU Overview The Open-Source Unicode Library, v3.2 Markus Scherer ICU Manager IBM Globalization Center of Competency

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 Agenda  Background  What is ICU?  Architecture Overview  ICU Features and recent additions  References  Q and A

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 Why Globalization?

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 Unicode  All world languages  Efficient and effective processing  Lossless data exchange  Enables single-binary global software  But… all languages ⇒ large, complex standard –1,400 pages + Annexes + additional standards –90,000+ characters –Major update every 3 years –70 character properties, many multi-valued –Affects many processes: display, line-break, regex, …

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 Locales  Features vary widely across languages & countries –Sorting, line breaks, date/time/number/currency formatting, codepage conversion, … –Performance is key: easy to do the right thing; hard to do it fast

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 What is ICU?  Globalization / Unicode / Locales  Mature, widely used set of C/C++ and Java libraries –Basis for Java 1.1 internationalization – but goes far beyond –“ICU4C”: C/C++ libraries; “ICU4J”: Java library  Very portable – identical results on all platforms / programming languages –C/C++: 30+ platforms/compilers –Java: IBM & Sun JDK  Full threading model; customizable; modular  Open source – but not viral  ICU 3.2: 78 languages; 118 countries; 870 codepages

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 Who uses ICU? (Examples)  Products Within IBM –DB2, COBOL, InfoPrint Manager, Lotus Notes, Lotus Workplace, Tivoli Presentation Services, WebSphere, XML Parser, …  Other Companies and Organizations –Adobe, Apple (Mac OS X), BEA, CERN, Cognos, Debian, HP, Inktomi, JD Edwards, Macromedia, Mathworks, Mozilla, NCR, OpenOffice, PayPal, SAP, Siebel, SIL, Software AG, Sun Microsystems (Solaris, Java), SuSE, Sybase, webMethods, …

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 ICU Features  Unicode text handling  Charset conversions (870+)  Collation & Searching  Locales (170+)  Resource Bundles  Calendar & Time zones  Complex-text layout engine  Unicode Regular Expressions  Breaks: word, line, …  Formatting –Date & time –Messages –Numbers & currencies  Transforms –Normalization –Casing –Transliterations

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 Architecture Overview 1  Locale Based Services –Locale is an identifier, not a container –Keywords for variants: –Recent addition: accept-language support  Resource inheritance: shared resources root en USIE de DECH zh HantHans TWCNTWCN Language Script Country

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 Architecture Overview 2  Open and Close Service Model –Open a service object, use it many times, close it when done –Better performance by avoiding setup costs per operation –Warning: use properly for maximum performace  ICU Threading Model –Multiple service objects in use simultaneously, with same or different attributes –Large resources shared in read-only cache

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 Architecture Overview 3  Data Driven Services –Customize at build-time or run-time –Interchange with other platforms; same results on each –Rule-based Collation, Word-breaks, Transforms –Pattern-based Formats, UnicodeSet –Table-based Character Conversion

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 Architecture Overview – ICU4C  Simple Error Handling –C++ subset for portability –Support for multi-threaded environment  Version Management –Multiple versions at the same time –Data and library versioning  String Buffer Management –Preflighting and overflow protection  Misc: Load/Unload ICU  Recent Additions: – Runtime-settable memory allocation and mutex functions

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 Architecture Overview – ICU4J  Supplement for Java  Core globalization (no character conversion or regular expressions, no GUI components) –We do supply complex text support for Sun  Modularized: products may add just needed functionality

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 ICU4J vs. JDK  CLDR 1.2 (Common Locale Data Repository)  Up-to-date globalization: standards-compliant; latest Unicode –Supplementary character (GB 18030, JIS X 213, HKSCS) Java 5 adds handling of supplementary characters –Full properties – JDK has only a fraction –Unicode Collation Algorithm –Local calendars (Thailand, Japan,…); ISO dates –Currencies, String Search, Int’l Domain Names –Transforms: Case, Scripts, Normalization  Much faster turn-around on bug fixes, enhancements

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 Unicode Text Handling  C –UChar*: null-terminated or with length  C++ –UnicodeString: full featured string class  Java –Uses normal JDK String, adds utilities  All handle supplementary characters –Required for GB 18030/JIS X 0213/HKSCS repertoires

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 Unicode Text Handling 2  All Unicode properties –Direct API Values, names, enumerations –UnicodeSet Fast, compact set operations Pattern-based (both Perl & POSIX syntax for properties) – \p{greek} vs. [:greek:] All properties: – [\p{lowercase}-[a-z]] – [\p{greek} & \p{uppercase}]

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 Data: Recent Additions  Conforms to CLDR 1.2 –50% more data than CLDR 1.0: adding many translated terms for languages, scripts, countries, currencies, and time zones. –Added data for new languages: Malayalam, Oriya, Welsh  Reduced multiplatform install image size  Improved XLIFF-ICU conversion tools  Locale canonicalization spec defined and implemented (C+J) –Provides interoperability with POSIX and.NET locale IDs, more RFC 3066 support

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 Character Set Conversion  Precise alias information: –When you ask for “SJIS”, you can request the precise definition by platform: Windows, IBM, Solaris,…  Buffer management –automatically handles characters that cross buffers  Customizations allowed for: –illegal sequences –undefined characters  Unicode Text Compression – SCSU, BOCU-1

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 Collation and Searching  Fast international comparison and string search; fully UCA compliant –Compressed sort keys, optimized string comparison, sublinear string search –incremental sortkeys for radix-sort  Precise binary sortkey stability over time  Fully data driven  API / rule customizations –strength, normalization, upper vs. lowercase first, ignore punctuation, sort digits as numbers, …

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 Collation and Searching: Recent Additions  Numeric sorting: sequences of digits can be sorted numerically instead of alphabetically –e.g., filenames would sort "ab-2" < "ab-10" –without material performance cost –with reduced sortkey length.  Significantly improved sorting orders for many other languages  Data in separate tree, for easier modularization and maintenance  getFunctionalEquivalent API allows for better caching and UI support.

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 Calendar & Time Zones  International Calendars – Arabic, Buddhist, Hebrew, Japanese –Required for correct presentation of dates in some countries  Olson timezone support, with localizations  Recent Additions: –RFC822 time zone format support in DateFormat (C+J) for compatibility. –“Universal Time” conversions for high-precision date/time computations

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 Formatting  Date & time: 8 formats per locale  Messages –Completely localizable, Plural support  Numbers & currencies –Scientific Notation, Spelled-out (checks, etc.) –Full Orthogonal Currency support INRIn Hindi: INRIn English:Rs. 1, INRIn German:Rs ,57  Recent Additions –POSIX migration library –Allows parsing multiple currencies with one formatter –Short and stand-alone month/day names

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 Transforms  Unicode Normalization –Highly optimized for performance –performance utilities: concatenation, detection, comparison  Casing (upper, lower, title, folding)  General Transforms –Script transliterations –Half-width/Full-width, Hex, etc. –Chain transforms together, filter source characters –Rule-based, customizable at runtime.  IDNA: International Domain Names

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 Segmentation: word, line & sentence  Fast state-table implementation  Customizable –Rule-based – customizable at runtime –Special customizations, e.g. Thai  Recent Additions: – Greatly improved performance when going backwards (common case when doing line break) –Java The rules syntax has been extended. Rules can now return information about the types of characters they encountered. Common compiled (binary) rule format with ICU4C

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 Unicode Regular Expressions  Full Regex Implementation –C only: Java 1.4 has own package (though not as powerful)  All Unicode Properties –supported through UnicodeSet  Good performance –competitive with non-Unicode regex  Recent Additions –Now features a C API, instead of just C++.

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 Complex-text layout engine  Glyph processing, positioning & adjustment –ligature substitution, contextual forms, kerning, accent placement, Bidi scripts, etc.  Support for: –Drawing –Caret Display –Hit Testing –Selection Highlighting –Caret Movement –Layout Metrics –Line Break  Recent addition: Canonical Equivalence: a + ´ or á

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 References  ICU main site: – New URL –Links to Download ICU User Guide, Technical FAQ, Support, Bug Reports  Unicode Consortium – Unicode glossary, Unicode character database

ICU Overview: The Open-Source Unicode Library, v th Internationalization and Unicode Conference Berlin, Germany, April 2005 Questions and Answers