dope2/structures/list.js
2025-03-23 09:15:37 +01:00

51 lines
1.3 KiB
JavaScript

import { typedFnType } from "./function.js";
import { Type } from "../metacircular.js";
import { Int } from "../primitives/symbols.js";
import { DefaultMap } from "../util.js";
import { makeGeneric } from "../generics/generics.js";
const symbolList = Symbol('List');
const listTypeRegistry = new DefaultMap(elementType => ({
symbol: symbolList,
params: [elementType],
}));
// type constructor
export const lsType = elementType => listTypeRegistry.getdefault(elementType, true);
// 'normal' implementation
const emptyList = {l:[]};
const get = ls => i => ls.l[i];
const put = ls => i => elem => ({l: ls.l.with(Number(i), elem)});
// const push = ls => elem => ({l:ls.l.concat([elem])});
export const ModuleList = {l:[
// Type -> Type
...typedFnType(lsType, fnType => fnType
/* in */ (Type)
/* out */ (Type)
),
// [a]
{i: emptyList, t: makeGeneric(a => lsType(a))},
// [a] -> Int -> a
...typedFnType(get, fnType => makeGeneric(a => fnType
/* in */ (lsType(a))
/* out */ (fnType
/* in */ (Int)
/* out */ (a)
))),
// [a] -> Int -> a -> [a]
...typedFnType(put, fnType => makeGeneric(a => fnType
/* in */ (lsType(a))
/* out */ (fnType
/* in */ (Int)
/* out */ (fnType
/* in */ (a)
/* out */ (lsType(a))
)
))),
]};