glen/typocomath
2
0
Fork 0
Code Issues 3 Pull Requests Packages Projects Releases Wiki Activity

fix: Use intersection of matching types in AssociatedTypes<> lookup

Browse Source
This commit is contained in:
Glen Whitney 2023-08-23 09:49:48 -07:00
parent 76e144bc2a
commit 742ef55108
2 changed files with 8 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
src/interfaces/type.ts
View File

@ -13,6 +13,10 @@
* but that's OK, the generic parameter doesn't hurt in those cases. * but that's OK, the generic parameter doesn't hurt in those cases.
****/ ****/
type ValueIntersectionByKeyUnion<T, TKey extends keyof T> = {
[P in TKey]: (k: T[P])=>void
} [TKey] extends ((k: infer I)=>void) ? I : never
export interface AssociatedTypes<T> { export interface AssociatedTypes<T> {
undefined: { undefined: {
type: undefined type: undefined
@ -24,10 +28,10 @@ export interface AssociatedTypes<T> {
} }
type AssociatedTypeNames = keyof AssociatedTypes<unknown>['undefined'] type AssociatedTypeNames = keyof AssociatedTypes<unknown>['undefined']
type ALookup<T, Name extends AssociatedTypeNames> = { type ALookup<T, Name extends AssociatedTypeNames> = ValueIntersectionByKeyUnion<{
[K in keyof AssociatedTypes<T>]: [K in keyof AssociatedTypes<T>]:
T extends AssociatedTypes<T>[K]['type'] ? AssociatedTypes<T>[K][Name] : never T extends AssociatedTypes<T>[K]['type'] ? AssociatedTypes<T>[K][Name] : unknown},
}[keyof AssociatedTypes<T>] keyof AssociatedTypes<T>>
// For everything to compile, zero and one must be subtypes of T: // For everything to compile, zero and one must be subtypes of T:
export type ZeroType<T> = ALookup<T, 'zero'> & T export type ZeroType<T> = ALookup<T, 'zero'> & T

2
src/numbers/type.ts
View File

@ -8,7 +8,7 @@ export const number_type = {
declare module "../interfaces/type" { declare module "../interfaces/type" {
interface AssociatedTypes<T> { interface AssociatedTypes<T> {
numbers: { number: {
type: number type: number
zero: 0 zero: 0
one: 1 one: 1