MDA - misc/encoding/unicode

Comment:: is mainly used in document processing, XML and SGML applications
example: Euro symbol has code U+20AC
motivation: solve document exchange problem -- include all characters of all languages (on this planet only) -- living or dead -- natural or invented -- 250 writing systems and thousands of languages
syntax: U+XXXX (hexadecimal X)
Comment:: numbers below AND ABOVE 65535 are used (NOT 16 bit only!!) -- Unicode uses now 21 bits, UCS 32 bits
Comment:: classifies characters into letters, numbers, punctuation, accents, ... -- maps cases (a to A) -- defines how to display characters -- how to combine characters -- how to treat bidirectional text -- algorithms for sorting, case folding, regular expressions
history: v2.0: 38,885 assigned characters -- v3.0: 49,194 -- v3.2: 95,156 -- v4.0: 96,382
Comment:: ISO 8859-1 is embedded
Comment:: coordinated code points: Unicode standard by the Unicode consortium -- ISO 10646, Universal Multiple-Octet Character Set (UCS) by ISO -- "synchronized standards"
encoding: could be encoded with 4 bytes, but this is wasteful -- different encoding UCS-2, UCS-4, UTF-8, UTF-16, UTF-32

References: