UNPKG

4.59 kBTypeScriptView Raw
1import type { NumOrString } from "./prim.js";
2import type { Keys, Keys1, Keys2, Keys3, Keys4, Keys5, Keys6, Keys7, ValN } from "./keyval.js";
3import type { Head, Tail, IsEmpty } from "./tuple.js";
4/**
5 * Unchecked lookup path for nested data structures.
6 */
7export declare type Path = readonly NumOrString[] | NumOrString;
8/**
9 * Empty lookup path.
10 */
11export declare type Path0 = readonly [];
12/**
13 * Type checked lookup path (depth 1)
14 */
15export declare type Path1<T, A> = A extends Keys<T> ? readonly [A] : never;
16/**
17 * Type checked lookup path (depth 2)
18 */
19export declare type Path2<T, A, B> = A extends Keys<T> ? B extends Keys1<T, A> ? readonly [A, B] : never : never;
20/**
21 * Type checked lookup path (depth 3)
22 */
23export declare type Path3<T, A, B, C> = A extends Keys<T> ? B extends Keys1<T, A> ? C extends Keys2<T, A, B> ? readonly [A, B, C] : never : never : never;
24/**
25 * Type checked lookup path (depth 4)
26 */
27export declare type Path4<T, A, B, C, D> = A extends Keys<T> ? B extends Keys1<T, A> ? C extends Keys2<T, A, B> ? D extends Keys3<T, A, B, C> ? readonly [A, B, C, D] : never : never : never : never;
28/**
29 * Type checked lookup path (depth 5)
30 */
31export declare type Path5<T, A, B, C, D, E> = A extends Keys<T> ? B extends Keys1<T, A> ? C extends Keys2<T, A, B> ? D extends Keys3<T, A, B, C> ? E extends Keys4<T, A, B, C, D> ? readonly [A, B, C, D, E] : never : never : never : never : never;
32/**
33 * Type checked lookup path (depth 6)
34 */
35export declare type Path6<T, A, B, C, D, E, F> = A extends Keys<T> ? B extends Keys1<T, A> ? C extends Keys2<T, A, B> ? D extends Keys3<T, A, B, C> ? E extends Keys4<T, A, B, C, D> ? F extends Keys5<T, A, B, C, D, E> ? readonly [A, B, C, D, E, F] : never : never : never : never : never : never;
36/**
37 * Type checked lookup path (depth 7)
38 */
39export declare type Path7<T, A, B, C, D, E, F, G> = A extends Keys<T> ? B extends Keys1<T, A> ? C extends Keys2<T, A, B> ? D extends Keys3<T, A, B, C> ? E extends Keys4<T, A, B, C, D> ? F extends Keys5<T, A, B, C, D, E> ? G extends Keys6<T, A, B, C, D, E, F> ? readonly [A, B, C, D, E, F, G] : never : never : never : never : never : never : never;
40/**
41 * Type checked lookup path (depth 8)
42 */
43export declare type Path8<T, A, B, C, D, E, F, G, H> = A extends Keys<T> ? B extends Keys1<T, A> ? C extends Keys2<T, A, B> ? D extends Keys3<T, A, B, C> ? E extends Keys4<T, A, B, C, D> ? F extends Keys5<T, A, B, C, D, E> ? G extends Keys6<T, A, B, C, D, E, F> ? H extends Keys7<T, A, B, C, D, E, F, G> ? readonly [A, B, C, D, E, F, G, H] : never : never : never : never : never : never : never : never;
44/**
45 * Semi-typechecked lookup path (depth > 8). Only the first 8 levels are
46 * checked.
47 */
48export declare type DeepPath<T, A, B, C, D, E, F, G, H> = A extends Keys<T> ? B extends Keys1<T, A> ? C extends Keys2<T, A, B> ? D extends Keys3<T, A, B, C> ? E extends Keys4<T, A, B, C, D> ? F extends Keys5<T, A, B, C, D, E> ? G extends Keys6<T, A, B, C, D, E, F> ? H extends Keys7<T, A, B, C, D, E, F, G> ? readonly [A, B, C, D, E, F, G, H, ...NumOrString[]] : never : never : never : never : never : never : never : never;
49/**
50 * Returns `RES` if `PRED` is `never`, else `RES | undefined`
51 */
52export declare type OptVal<PRED, RES> = [PRED] extends [never] ? RES : RES | undefined;
53/**
54 * Returns true if `T` includes undefined.
55 */
56export declare type IsOpt<T> = T extends undefined ? true : never;
57/**
58 * Internal recursive helper type for {@link IsOptPath}.
59 */
60declare type IsOptR<T, K, P extends unknown[]> = K extends Keys<T> ? [true] extends [IsOpt<T[K]>] ? true : {
61 0: IsOptR<Required<T>[K], Head<P>, Tail<P>>;
62 1: never;
63}[IsEmpty<P>] : never;
64/**
65 * Returns true if given path contains any intermediate properties
66 * declared as optional in type `T`.
67 *
68 * Reference:
69 * https://stackoverflow.com/q/60869412/294515
70 */
71export declare type IsOptPath<T, P extends unknown[]> = P extends [] ? never : IsOptR<T, Head<P>, Tail<P>>;
72/**
73 * Similar to {@link PathVal}, but also takes into account if given path
74 * contains any intermediate properties declared as optional in type
75 * `T`. If that's the case, returns union of `undefined` and inferred
76 * value for path, else just the latter.
77 *
78 * Context & reference: https://stackoverflow.com/q/60869412/294515
79 */
80export declare type OptPathVal<T, P extends unknown[]> = OptVal<IsOptPath<T, P>, ValN<T, P>>;
81/**
82 * Returns nested value type for given path into `T` or `never` if path
83 * is incompatible with `T`.
84 */
85export declare type PathVal<T, P extends unknown[]> = ValN<T, P>;
86export {};
87//# sourceMappingURL=path.d.ts.map
\No newline at end of file