The Annoyance Filter.pdf - Fourmilab

78 SHIFT-JIS INTERPRETER CLASS ANNOYANCE-FILTER §94
94. Our getNextDecodedChar implementation is a bit more complicated than the default provided by
the parent class. In addition to handling ASCII and two byte character codes, we also wish to interpret
Katakana single byte characters, which are emitted without spaces between them.
〈 Class implementations 11 〉 +≡
string Shift JIS MBCSinterpreter ::getNextDecodedChar (void)
{
assert(dp ≠ Λ);
}
int dc = dp ⃗ getNextDecodedChar ( );
if (dc < 0) {
return ""; /∗ End of input stream ∗/
}
if (dc < # A1) {
string r(1, static cast〈char〉(dc)); /∗ ASCII character ∗/
}
return r;
ostringstream os ;
os .setf (ios ::uppercase );
if ((dc ≥ # A1) ∧ (dc ≤ # DF)) {
os ≪ "SJIS−K" ≪ hex ≪ dc ≪ dec; /∗ Katakana—don’t space around characters ∗/
}
else {
os ≪ prefix ≪ "SJIS−" ≪ hex ≪ dc ≪ dec ≪ suffix ; /∗ Kanji–space on both sides ∗/
}
return os .str ( );
95. Korean Interpreter class.
This interpreter class parses Korean characters into tokens which downstream parsers can comprehend.
This type (usually expressed as a charset of euc−kr) is uncommon, but we handle it to illustrate an
interpreter for an alphabetic non-Western language.
〈 Class definitions 10 〉 +≡
class KR MBCSinterpreter : public MBCSinterpreter {
public:
virtual string name (void)
{
return "KR";
}
};