CJKV Information Processing, 2nd Edition

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Chapter 9: Information Processing Techniques

As you can see from these examples, this problem varies in intensity depending on the

encoding method, and even on the soware you are using—compare the two types of out-

put you get for ISO-2022 encoding, using dierent applications. Some encodings require

slightly more overhead than simplistically treating multiple-byte characters as an insepa-

rable unit. For example, when dealing with ISO-2022 encoding, you must also remember

to insert and perhaps even delete escape sequences.

Character Attribute Detection Using C Macros

A useful function oen supported in CJKV text-processing programs—or for that matter

in most text-processing systems—is the ability to determine the attributes of characters

within a le. For example, it is oen convenient to obtain a listing of the numbers of Chi-

nese characters, kana, and other characters in a le. One can even break those categories

down further, such as kana into katakana and hiragana, ideographs into separate levels,

and so on.

e C programming language has a useful macro facility that allows programmers to

specify simple commands that can be used oen within a program. Macros are similar in

concept to functions, but require less work, although perhaps more thought.

As an example, several C macro denitions for detecting the attributes of Japanese (JIS X

0208:1997) characters are pro