src/Trait.ts

@@ -9,7 +9,7 @@ export type AddAbstractToImplClass<
     Abstract  extends {},
 > = (
     Class<
-        InstanceType<ImplClass> & Abstract,
+        Abstract & InstanceType<ImplClass>,
         ConstructorParameters<ImplClass>
     > &
     StaticMembers<ImplClass>

src/TraitExpression.ts

@@ -4,11 +4,11 @@ import { AbstractTag, RemoveAbstractFromImplClass, Trait, TraitApplierSuperTag }
 import { ExtendFn, SimplifyFn, StaticMembersFn } from "./util"
 
 
-type RemoveSupertraitsAbstractFromAbstract<Left, Right> = {
+// type RemoveSupertraitsAbstractFromAbstract<Left, Right> = {
-    [Key in Extract<keyof Left, keyof Right>]: Left[Key]
+//     [Key in Extract<keyof Left, keyof Right>]: Left[Key]
-} & {
+// } & {
-    [Key in Exclude<keyof Left, keyof Right>]: Left[Key]
+//     [Key in Exclude<keyof Left, keyof Right>]: Left[Key]
-}
+// }
 
 
 export class TraitExpression<
@@ -61,7 +61,8 @@ export class TraitExpression<
     ) {
         return new Trait(
             this,
-            {} as RemoveSupertraitsAbstractFromAbstract<SubtraitAbstract, Implements<typeof this>>,
+            // {} as RemoveSupertraitsAbstractFromAbstract<SubtraitAbstract, Implements<typeof this>>,
+            {} as SubtraitAbstract,  // TODO: find a way to cleanly substract Implements<typeof this> from this.
             apply as any as (Super: AbstractClass<{}>) => RemoveAbstractFromImplClass<SubtraitImplClassWithAbstract, SubtraitAbstract>,
         )
     }

src/tests.ts

@@ -63,25 +63,16 @@ const exp = expression
         PrintsHelloOnNew,
         Identifiable<bigint>(),
         // Identifiable<number>(),
-        StatefulSubscription,
+        ActiveStatefulSubscription,
     )
     .build()
 
 type Abs = Implements<typeof exp>
 
-// exp.subtrait(
-//     s => {
-//         interface Subtrait extends (typeof s) {
-
-//         }
-
-//         return abstract<Subtrait>()
-//     },
-// )
-
 class User extends exp.extends implements Implements<typeof exp> {
     readonly isStatefulSubscription: true = true
-    declare status: { _tag: "awaitingPayment" } | { _tag: "active"; activeSince: Date; expiresAt?: Date | undefined } | { _tag: "expired"; expiredSince: Date }
+    readonly isActiveStatefulSubscription: true = true
+    declare status: { _tag: "active"; activeSince: Date; expiresAt?: Date | undefined }
     id: bigint = -1n
 }
 

src/util/class.ts

@@ -1,15 +0,0 @@
-import { Fn } from "hotscript"
-import { AbstractClass } from "type-fest"
-
-
-/**
- * Represents the static members of a class.
- * @template Class - A class extending AbstractClass.
- */
-export type StaticMembers<Class extends AbstractClass<any>> = (
-    Omit<Class, "prototype">
-)
-
-export interface StaticMembersFn extends Fn {
-    return: StaticMembers<this["arg0"]>
-}

src/util/index.ts

@@ -1,4 +1,3 @@
-export * from "./class"
 export * from "./extend"
 export * from "./inheritance"
 export * from "./misc"

src/util/misc.ts

@@ -1,5 +1,5 @@
 import { Fn } from "hotscript"
-import { Simplify } from "type-fest"
+import { AbstractClass, Simplify } from "type-fest"
 
 
 /**
@@ -9,10 +9,17 @@ import { Simplify } from "type-fest"
  */
 export type CommonKeys<A, B> = Extract<keyof A, keyof B>
 
-export type KeysOnlyInLeft<Left, Right> = {
-    [K in Exclude<keyof Left, keyof Right>]: Left[K]
-}
-
 export interface SimplifyFn extends Fn {
     return: Simplify<this["arg0"]>
 }
+
+/**
+ * Represents the static members of a class.
+ * @template Class - A class extending AbstractClass.
+ */
+export type StaticMembers<Class extends AbstractClass<any>> = (
+    Omit<Class, "prototype">
+)
+export interface StaticMembersFn extends Fn {
+    return: StaticMembers<this["arg0"]>
+}