t_wの輪郭

WITH hira_to_kata as MATERIALIZED (
					SELECT hira, kata
					FROM (
						SELECT 'あ' as hira, 'ア' as kata
						UNION SELECT 'い' as hira, 'イ' as kata
						UNION SELECT 'う' as hira, 'ウ' as kata
						UNION SELECT 'え' as hira, 'エ' as kata
						UNION SELECT 'お' as hira, 'オ' as kata
						UNION SELECT 'か' as hira, 'カ' as kata
						UNION SELECT 'き' as hira, 'キ' as kata
						UNION SELECT 'く' as hira, 'ク' as kata
						UNION SELECT 'け' as hira, 'ケ' as kata
						UNION SELECT 'こ' as hira, 'コ' as kata
						UNION SELECT 'さ' as hira, 'サ' as kata
						UNION SELECT 'し' as hira, 'シ' as kata
						UNION SELECT 'す' as hira, 'ス' as kata
						UNION SELECT 'せ' as hira, 'セ' as kata
						UNION SELECT 'そ' as hira, 'ソ' as kata
						UNION SELECT 'た' as hira, 'タ' as kata
						UNION SELECT 'ち' as hira, 'チ' as kata
						UNION SELECT 'つ' as hira, 'ツ' as kata
						UNION SELECT 'て' as hira, 'テ' as kata
						UNION SELECT 'と' as hira, 'ト' as kata
						UNION SELECT 'な' as hira, 'ナ' as kata
						UNION SELECT 'に' as hira, 'ニ' as kata
						UNION SELECT 'ぬ' as hira, 'ヌ' as kata
						UNION SELECT 'ね' as hira, 'ネ' as kata
						UNION SELECT 'の' as hira, 'ノ' as kata
						UNION SELECT 'は' as hira, 'ハ' as kata
						UNION SELECT 'ひ' as hira, 'ヒ' as kata
						UNION SELECT 'ふ' as hira, 'フ' as kata
						UNION SELECT 'へ' as hira, 'ヘ' as kata
						UNION SELECT 'ほ' as hira, 'ホ' as kata
						UNION SELECT 'ま' as hira, 'マ' as kata
						UNION SELECT 'み' as hira, 'ミ' as kata
						UNION SELECT 'む' as hira, 'ム' as kata
						UNION SELECT 'め' as hira, 'メ' as kata
						UNION SELECT 'も' as hira, 'モ' as kata
						UNION SELECT 'や' as hira, 'ヤ' as kata
						UNION SELECT 'ゆ' as hira, 'ユ' as kata
						UNION SELECT 'よ' as hira, 'ヨ' as kata
						UNION SELECT 'ら' as hira, 'ラ' as kata
						UNION SELECT 'り' as hira, 'リ' as kata
						UNION SELECT 'る' as hira, 'ル' as kata
						UNION SELECT 'れ' as hira, 'レ' as kata
						UNION SELECT 'ろ' as hira, 'ロ' as kata
						UNION SELECT 'わ' as hira, 'ワ' as kata
						UNION SELECT 'を' as hira, 'ヲ' as kata
						UNION SELECT 'ん' as hira, 'ン' as kata
						UNION SELECT 'ー' as hira, 'ー' as kata

						UNION SELECT 'が' as hira, 'ガ' as kata
						UNION SELECT 'ぎ' as hira, 'ギ' as kata
						UNION SELECT 'ぐ' as hira, 'グ' as kata
						UNION SELECT 'げ' as hira, 'ゲ' as kata
						UNION SELECT 'ご' as hira, 'ゴ' as kata

						UNION SELECT 'ざ' as hira, 'ザ' as kata
						UNION SELECT 'じ' as hira, 'ジ' as kata
						UNION SELECT 'ず' as hira, 'ズ' as kata
						UNION SELECT 'ぜ' as hira, 'ゼ' as kata
						UNION SELECT 'ぞ' as hira, 'ゾ' as kata

						UNION SELECT 'だ' as hira, 'ダ' as kata
						UNION SELECT 'ぢ' as hira, 'ヂ' as kata
						UNION SELECT 'づ' as hira, 'ヅ' as kata
						UNION SELECT 'で' as hira, 'デ' as kata
						UNION SELECT 'ど' as hira, 'ド' as kata

						UNION SELECT 'ば' as hira, 'バ' as kata
						UNION SELECT 'び' as hira, 'ビ' as kata
						UNION SELECT 'ぶ' as hira, 'ブ' as kata
						UNION SELECT 'べ' as hira, 'ベ' as kata
						UNION SELECT 'ぼ' as hira, 'ボ' as kata

						UNION SELECT 'ぱ' as hira, 'パ' as kata
						UNION SELECT 'ぴ' as hira, 'ピ' as kata
						UNION SELECT 'ぷ' as hira, 'プ' as kata
						UNION SELECT 'ぺ' as hira, 'ペ' as kata
						UNION SELECT 'ぽ' as hira, 'ポ' as kata
					)
				),

使い方はこうでござる。
いや、まあ、うん、普通にプログラム書けってかんじだ。

WITH RECURSIVE kata as (
					SELECT
						'' as kata,
						0 as index

					UNION

					SELECT
						CONCAT(kata.kata, hira_to_kata.kata) as kata,
						kata.index + 1 as index
					FROM given, kata, hira_to_kata
					WHERE true
						AND given.text[kata.index + 1] = hira_to_kata.hira
				)

SELECT kata
			FROM kata, given
			WHERE true
				AND kata.index = LENGTH(given.text)

字による抽出は概念化と一致しない。

漢字であればある程度の概念の香りが残るが、ひらがなにまで分解すればそこに概念を見出すことはほぼ不可能。

ほん
まか

のようなカスタム絵文字はひらがなが部品として組み合わさった一字として見ることができ、あたかも、ひらがなから漢字が作られているかのように見える。

厳密なことを言えば、漢を起源としていないため、これを「漢字」と呼ぶのは不適切かもしれない。

正しさはともかくとして、そういう印象が生じたということだけ記録しておきたかった。