30 lines
1.1 KiB
TypeScript
30 lines
1.1 KiB
TypeScript
import type { GenericEmbedded } from "./embedded";
|
|
import type { Annotated } from "./annotated";
|
|
|
|
export const IsPreservesAnnotated = Symbol.for('IsPreservesAnnotated');
|
|
|
|
export function isAnnotated<T = GenericEmbedded>(x: any): x is Annotated<T>
|
|
{
|
|
return !!x?.[IsPreservesAnnotated];
|
|
}
|
|
|
|
export function is(a: any, b: any): boolean {
|
|
if (isAnnotated(a)) a = a.item;
|
|
if (isAnnotated(b)) b = b.item;
|
|
if (Object.is(a, b)) return true;
|
|
if (typeof a !== typeof b) return false;
|
|
if (typeof a === 'object') {
|
|
if (a === null || b === null) return false;
|
|
if ('equals' in a && typeof a.equals === 'function') return a.equals(b, is);
|
|
if (Array.isArray(a) && Array.isArray(b)) {
|
|
const isRecord = 'label' in a;
|
|
if (isRecord !== 'label' in b) return false;
|
|
if (isRecord && !is((a as any).label, (b as any).label)) return false;
|
|
if (a.length !== b.length) return false;
|
|
for (let i = 0; i < a.length; i++) if (!is(a[i], b[i])) return false;
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|