type Pure = { [P in keyof T]: T[P] extends object ? Pure : T[P] } type SetProperty = { [P in (keyof T) | K]: P extends K ? V : P extends keyof T ? T[P] : never } type Token = | { kind: "objS" } | { kind: "objE" } | { kind: "arrS" } | { kind: "arrE" } | { kind: "comma" } | { kind: "colon" } | { kind: "str", value: string } | { kind: "true" } | { kind: "false" } | { kind: "null" } type ParseResult = [T, K] type Take = S extends `${infer head}${infer rest}` ? [head, rest] : ["", ""] type Unescape = S extends "" ? res : S extends `\\b${infer R}` ? Unescape : S extends `\\f${infer R}` ? Unescape : S extends `\\n${infer R}` ? Unescape : S extends `\\r${infer R}` ? Unescape : S extends `\\t${infer R}` ? Unescape : Take extends [infer Char extends string, infer R extends string] ? Unescape : "" // unreachable type Tokenize = Take extends [infer Char, infer R extends string] ? Char extends "" ? T : Char extends " " | "\n" | "\r" | "\t" ? Tokenize : Char extends `{` ? Tokenize : Char extends `}` ? Tokenize : Char extends `[` ? Tokenize : Char extends `]` ? Tokenize : Char extends `:` ? Tokenize : Char extends `,` ? Tokenize : S extends `true${infer RR}` ? Tokenize : S extends `false${infer RR}` ? Tokenize : S extends `null${infer RR}` ? Tokenize : S extends `"${infer s}"${infer RR}` ? Tokenize }]> : [] : [] type TestTokenizeObj = Expect, [ { kind: "objS" }, { kind: "str", value: "aa" }, { kind: "colon" }, { kind: "true" }, { kind: "comma" }, { kind: "str", value: "cc" }, { kind: "colon" }, { kind: "str", value: "foo" }, { kind: "objE" }, ] >> type TestTokenizeArr = Expect, [{ kind: "arrS" }, { kind: "str", value: "Hello" }, { kind: "comma" }, { kind: "true" }, { kind: "comma" }, { kind: "false" }, { kind: "comma" }, { kind: "null" }, { kind: "arrE" }] >> type ParseLiteral = T extends [infer Cur extends Token, ...infer R extends Token[]] ? Cur extends { kind: "objS" } ? ParseObject : Cur extends { kind: "arrS" } ? ParseArray : Cur extends { kind: "str" } ? [Cur["value"], R] : Cur extends { kind: "true" } ? [true, R] : Cur extends { kind: "false" } ? [false, R] : Cur extends { kind: "null" } ? [null, R] : [never, T] : [never, T] /** consume * "foo": true, * "bar": false */ type ParsePair = T extends [infer K extends { kind: "str", value: string }, { kind: "colon" }, ...infer R extends Token[]] ? ParseLiteral extends [infer V, infer Tail extends Token[]] ? Tail extends [{ kind: "objE" }, ...unknown[]] ? [SetProperty, Tail] : Tail extends [{ kind: "comma" }, ...infer Next extends Token[]] ? ParsePair> : [never, Tail] : never : T[0] extends { kind: "objE" } ? [{}, T] : [never, T] type TestPair = Expect, [{ aa: true, bb: false, cc: "foo" }, [{ kind: "objE" }]]>> type ParseObject = T extends [{ kind: "objS" }, ...infer R extends Token[]] ? ParsePair extends [infer kv, infer RR extends Token[]] ? RR extends [{ kind: "objE" }, ...infer RRR extends Token[]] ? [kv, RRR] : [never, RR] : never : [never, T] type TestObj = Expect>, [{ "aa": true, "bb": false, "cc": "foo" }, []]>> type TestObj2 = ParseObject> type ParseArray = T extends [infer Cur extends Token, ...infer R extends Token[]] ? Cur extends { kind: "arrS" } ? result["length"] extends 0 ? ParseArray : [never, R] : Cur extends { kind: "arrE" } ? [result, R] : Cur extends { kind: "comma" } ? ParseArray : Cur extends { kind: "str" | "true" | "false" | "null" | "objS" | "arrS" } ? ParseLiteral extends [infer V, infer RToken extends Token[]] ? ParseArray : [never, R] : [never, R] : [never, T] type TestArr = Expect, [["foo", "bar", true, false], []] >> type Parse = Pure>[0]>

提出日時	問題	ユーザー	結果	詳細
2026-03-22 16:47:42	JSON Parser	ookkoouu	Accepted	詳細
2023-09-20 15:53:30	JSON Parser	sankantsu	Accepted	詳細