src/TraitExpression.ts

@@ -1,9 +1,11 @@
-import { Call, Pipe, Tuples } from "hotscript"
+import { Call, Fn, Pipe, Tuples } from "hotscript"
 import { AbstractClass, Class, Opaque } from "type-fest"
-import { AbstractTag, Trait, TraitApplierSuperTag, TraitOwnAbstractFn, TraitOwnImplClassFn, TraitOwnImplInstanceFn } from "."
+import { AbstractTag, Trait, TraitAbstractFn, TraitApplierSuperTag, TraitOwnAbstractFn, TraitOwnImplClassFn, TraitOwnImplInstanceFn, TraitSupertraitsFn } from "."
 import { ExtendFn, ExtendableFn, SimplifyFn, StaticMembersFn } from "./util"
 
 
+export class TraitExpressionNullSuperclass {}
+
 export class TraitExpression<
     Super  extends AbstractClass<{}>,
     Traits extends Trait<any, any, any>[],
@@ -58,6 +60,46 @@ export class TraitExpression<
     }
 }
 
+export const emptyTraitExpression = new TraitExpression(TraitExpressionNullSuperclass, [] as const)
+
+interface PrependTraitSupertraitsFn extends Fn {
+    return: [
+        ...Call<TraitSupertraitsFn, this["arg0"]>,
+        this["arg0"],
+    ]
+}
+export interface TraitExpressionTraitsFn extends Fn {
+    return: this["arg0"] extends TraitExpression<any, infer Traits>
+        ? Call<Tuples.FlatMap<PrependTraitSupertraitsFn>, Traits>
+        : never
+}
+
+export interface TraitExpressionAbstractFn extends Fn {
+    return: this["arg0"] extends TraitExpression<any, infer Traits>
+        ? Pipe<Traits, [
+            TraitAbstractFn,
+            ExtendFn,
+        ]>
+        : never
+}
+
+export interface TraitExpressionInstanceFn extends Fn {
+    return: this["arg0"] extends TraitExpression<infer Super, infer Traits>
+        ? Pipe<Traits, [
+            TraitAbstractFn,
+            ExtendFn,
+        ]>
+        : never
+}
+
+export interface TraitExpressionStaticFn extends Fn {
+    return: this["arg0"] extends TraitExpression<infer Super, infer Traits>
+        ? Pipe<Traits, [
+            TraitAbstractFn,
+            ExtendFn,
+        ]>
+        : never
+}
 
 
 export type Implements<Exp extends TraitExpression<any, any>> = (
@@ -158,8 +200,4 @@ type GetTraitExpression<
 )
 
 
-export class NullTraitExpressionSuperclass {}
-
-export const expression = new TraitExpressionBuilder(
-    new TraitExpression(NullTraitExpressionSuperclass, [] as const)
-)
+export const expression = new TraitExpressionBuilder(emptyTraitExpression)

src/tests.ts

@@ -1,4 +1,4 @@
-import { Implements, TraitAbstractMembers, abstract, expression, trait } from "."
+import { Implements, abstract, expression, trait } from "."
 
 
 const PrintsHelloOnNew = trait(
@@ -32,14 +32,14 @@ const StatefulSubscription = trait(
     Super => class StatefulSubscription extends Super {},
 )
 
-interface ActiveStatefulSubscriptionAbstractMembers extends TraitAbstractMembers<typeof StatefulSubscription> {
-    readonly status: { _tag: "active", activeSince: Date, expiresAt?: Date }
-}
+// interface ActiveStatefulSubscriptionAbstractMembers extends TraitAbstractMembers<typeof StatefulSubscription> {
+//     readonly status: { _tag: "active", activeSince: Date, expiresAt?: Date }
+// }
 
-const ActiveStatefulSubscription = trait(
-    abstract<ActiveStatefulSubscriptionAbstractMembers>(),
-    Super => class ActiveStatefulSubscription extends Super {},
-)
+// const ActiveStatefulSubscription = trait(
+//     abstract<ActiveStatefulSubscriptionAbstractMembers>(),
+//     Super => class ActiveStatefulSubscription extends Super {},
+// )
 
 
 class TestSuperclass {

src/trait.ts

@@ -1,7 +1,7 @@
 import { Call, Fn } from "hotscript"
 import { AbstractClass, Class, Opaque } from "type-fest"
-import { AbstractTag, NullTraitExpressionSuperclass, TraitExpression } from "."
-import { StaticMembers } from "./util"
+import { AbstractTag, TraitExpression, TraitExpressionAbstractFn, TraitExpressionNullSuperclass, TraitExpressionTraitsFn, emptyTraitExpression } from "."
+import { ExtendFn, StaticMembers } from "./util"
 
 
 type AddAbstractToImplClass<
@@ -28,7 +28,7 @@ type RemoveAbstractFromImplClass<
 
 
 export class Trait<
-    Super     extends TraitExpression<typeof NullTraitExpressionSuperclass, any>[],
+    Super     extends TraitExpression<typeof TraitExpressionNullSuperclass, any>,
     Abstract  extends {},
     ImplClass extends Class<{}, []>,
 > {
@@ -54,7 +54,7 @@ export interface TraitOwnImplClassFn extends Fn {
 export type TraitOwnImplClass<T> = Call<TraitOwnImplClassFn, T>
 
 export interface TraitOwnImplInstanceFn extends Fn {
-    return: this["arg0"] extends Trait<any, infer Abstract, infer ImplClass>
+    return: this["arg0"] extends Trait<any, any, infer ImplClass>
         ? InstanceType<ImplClass>
         : never
 }
@@ -77,6 +77,22 @@ export interface TraitOwnInstanceFn extends Fn {
 export type TraitOwnInstance<T> = Call<TraitOwnInstanceFn, T>
 
 
+export interface TraitSupertraitsFn extends Fn {
+    return: this["arg0"] extends Trait<infer Super, any, any>
+        ? Call<TraitExpressionTraitsFn, Super>
+        : never
+}
+
+export interface TraitAbstractFn extends Fn {
+    return: this["arg0"] extends Trait<infer Super, infer Abstract, any>
+        ? Call<ExtendFn, [
+            ...Call<TraitExpressionAbstractFn, Super>,
+            Abstract,
+        ]>
+        : never
+}
+
+
 export type TraitApplierSuperTag = "@thilawyn/traitify-ts/TraitApplierSuper"
 
 export function trait<
@@ -89,7 +105,7 @@ export function trait<
     ),
 ) {
     return new Trait(
-        []       as const,
+        emptyTraitExpression,
         abstract as Abstract,
         apply    as any as (Super: AbstractClass<{}>) => RemoveAbstractFromImplClass<ImplClassWithAbstract, Abstract>,
     )