Parsing CSV with TypeScript Types

ParseCSV.md

Ever need to parse CSV with TypeScript, no? Me niether but here goes.

I redid this one so that can handle quotes more correctly. No that CSV actually parsable, but at least it may almost might be right. I'd like to add csv to objects instead of array of arrays... but I gotta think on that.

type Line<T, D extends string = ',', R extends string[] = []> = 
    T extends '' ? R :
    T extends ` ${infer Rest}` ? Line<Rest, D, R> :
    T extends `${infer Rest} ` ? Line<Rest, D, R> : 
    T extends `"${infer Field}"${D}${infer Rest}` ? Line<Rest, D, [...R, Field]> :
    T extends `'${infer Field}'${D}${infer Rest}` ? Line<Rest, D, [...R, Field]> :
    T extends `${infer Field}${D}${infer Rest}` ? Line<Rest, D, [...R, Field]> :
    [...R, T];


type Lines<T, D extends string = ',', R extends string[][] = []> = 
T extends '' ? R :
T extends `${infer L}\n${infer N}` ? [ ...R, Line<L, D>, ...Lines<N, D>] :
[...R, Line<T,D>];


type CSV<T, D extends string = ',', R extends string[][] = []> = 
    T extends '' ? R : 
    T extends `#${infer Header}\n${infer Rest}` ? [Line<Header, D>, ...Lines<Rest, D>] :
    [...R, ...Lines<T, D>];


type L1 = Line<'all,good,dogs'>;
type L2 = Line<'"all, good " , dogs'>;
type L3 = Line<'all, "good dogs"'>;

type H1 = CSV<`#id,name,age\n1, "alice jo", 22\n2, 'bob ann', 33\n '3 3', super, do`>
type S1 = CSV<`id,name,age\n1, "alice jo", 22\n2, 'bob ann', 33\n '3 3', super, do`>
type D1 = CSV<`id|name|age\n1| "alice jo"| 22\n2| 'bob ann'| 33\n '3 3'| super| do`, "|">

playground