How does a romanization IME work for Chinese?
The most commonly used romanization in use today is 漢語拼音 Hànyǔ Pīnyīn, or just “pinyin” for short. Pinyin represents each syllable of Beijing Chinese (PRC Modern Standard) by means of a combination of Latin characters, optionally modified by tone marks. The tone marks consist either of numbers at the end of the syllable or diacritics placed on the main vowel. A given syllable as romanized in pinyin may correspond to one or — more often — to many particular Chinese characters. The user types in the pinyin syllable as a sequence of Latin characters (and the tone indicators). When the syllable is to be converted to the correct Chinese character for input, the input method presents the user with a palette of characters having that pronunciation, from which to make the appropriate selection by keyboard (or mouse) action. Single syllable pronunciations involve lots of homophones in Chinese (and even more so in Japanese), but disyllabic word combinations are much less ambiguous. So if the inp
