Internationalization Module User’s Guide : Chapter 3 Character and String Processing : Character Properties : Character Directionality
Character Directionality
All Unicode characters are assigned a directionality type in the Unicode Character Database. RWUCharTraits provides a BidirectionalCategory enum with values that identify the various directionality types, such as LeftToRight, RightToLeft, RightToLeftArabic, LeftToRightEmbedding, RightToLeftOverride, and so on. (See the documentation for RWUCharTraits in the SourcePro API Reference Guide for a complete list of enumerated values.) The values in this enumeration correspond to the bidirectional category property codes defined in the Unicode Character Database, as described in Unicode Standard Annex #9, “The Bidirectional Algorithm”:
http://www.unicode.org/unicode/reports/tr9
The static method RWUCharTraits::getBidirectionalCategory() returns the value in the BidirectionalCategory enumeration identifying the directionality type associated with a given code point.