get template literals working with multiple dependencies

.gitignore

@@ -3,6 +3,7 @@
 # Typescript
 # emitted code
 obj
+build
 
 # ---> Node
 # Logs

package.json5

@@ -4,7 +4,7 @@
    description: 'A hopeful final typescipt-pragmatic mathjs proof-of-concept',
    main: 'index.ts',
    scripts: {
-      test: 'echo "Error: no test specified" && exit 1',
+      go: 'tsc && node build/infer.js'
    },
    keywords: [
       'math',

pnpm-lock.yaml

@@ -1,14 +1,17 @@
-lockfileVersion: 5.4
+lockfileVersion: '6.0'
 
-specifiers:
-  typescript: ^4.9.3
+settings:
+  autoInstallPeers: true
+  excludeLinksFromLockfile: false
 
 devDependencies:
-  typescript: 4.9.3
+  typescript:
+    specifier: ^4.9.3
+    version: 4.9.3
 
 packages:
 
-  /typescript/4.9.3:
+  /typescript@4.9.3:
     resolution: {integrity: sha512-CIfGzTelbKNEnLpLdGFgdyKhG23CKdKgQPOBc+OUNrkJ2vr+KSzsSV5kq5iWhEQbok+quxgGzrAtGWCyU7tHnA==}
     engines: {node: '>=4.2.0'}
     hasBin: true

src/infer.ts

@@ -5,53 +5,71 @@
  * infer TypeScript interfaces from that using infer in template literal types.
  */
 
-type T = {} // TODO: how to do generics?
-
 const create = createFactory<{
-    number: number
-    bigint: bigint
-    T: T // TODO: how to do generics?
-    'Complex<T>': unknown  // TODO: how to do generics?
+  number: number
+  bigint: bigint
+  string: string
+  // T: T // TODO: how to do generics?
+  // 'Complex<T>': unknown  // TODO: how to do generics?
 }>()
 
 
 // TODO: how to pass config?
-// FIXME: multiple signatures do not work
+// These are the interfaces:
+const Multiply = 'multiply(number,number)=>number'
+const Zero = 'zero(number)=>number'
 
-const createSquare = create({
-        multiply: '(number, number) : number',
-        // zero: '(number) : number'
-    },dep => {
-        return (x: number) => dep.multiply(x, x)
-    }
-)
+const createSquare = create([Multiply, Zero],dep => {
+  return (x: number) => dep.multiply(x, x)
+})
 
 // the code works in JS, and works in TS
 const multiply = (a: number, b: number) => a * b
-const square = createSquare({ multiply })
+const zero = (a: number) => 0
+const square = createSquare({ multiply, zero })
 console.log('square', square(8)) // 64
 
 function createFactory<BaseTypes extends Record<string, unknown>>() {
-    type K = string & keyof BaseTypes
+  type BaseTypeNames = string & keyof BaseTypes
+  type ResolveType<TypeName extends BaseTypeNames> = BaseTypes[TypeName]
 
-    type ResolveType<T extends K> = BaseTypes[T]
+  type Value<K> = K
 
-    type ResolveArguments<S extends string> =
-        S extends '' ? [] :
-          S extends `${infer T extends K}, ${infer U}`
-            ? [ResolveType<T>, ...ResolveArguments<U>]
-            : S extends `${infer T extends K}` ? [ResolveType<T>]
-              : never;
+  type ResolveArguments<S extends string> = S extends ''
+    ? []
+    : S extends `${infer Arg extends BaseTypeNames},${infer Tail}`
+      ? [ResolveType<Arg>, ...ResolveArguments<Tail>]
+      : S extends `${infer Arg extends BaseTypeNames}`
+        ? [ResolveType<Arg>]
+        : never
 
-    type ResolveFunctionDef<T> =
-        T extends `${infer Name}(${infer Args}) : ${infer L extends K}`
-            ? (...args: ResolveArguments<Args>) => ResolveType<L>
-            : never
+  type FunctionDefinition<FnType> =
+    FnType extends Value<infer K>
+      ? K extends `${infer Name}(${infer Args})=>${infer ReturnType extends BaseTypeNames}`
+        ? Record<Name, (...args: ResolveArguments<Args>) => ResolveType<ReturnType>>
+        : never
+      : never
 
-    return function create<T extends string, U extends string, V>(
-        dependencies: { [L in T]: U },
-        callback: (deps: { [L in T]: ResolveFunctionDef<U> }) => V
-    ) {
-        return callback
-    }
+  // inspired by: https://stackoverflow.com/questions/68391632/infer-type-from-array-literal
+  type DepRecord<
+    Arr extends Array<Value<any>>,
+    Result extends Record<string, any> = {}
+  > = Arr extends []
+    ? Result
+    : Arr extends [infer H, ...infer Tail]
+      ? Tail extends Array<Value<any>>
+        ? H extends Value<any>
+          ? DepRecord<Tail, Result & FunctionDefinition<H>>
+          : never
+        : never
+      : never
+
+  return function create<K extends string, Dependencies extends Value<K>[], W>(
+    dependencies: [...Dependencies],
+    callback: (deps: DepRecord<[...Dependencies]>) => W
+  ) {
+    console.log('Creating typed-function with dependencies:', dependencies)
+    // TODO: create a typed-function for real
+    return callback
+  }
 }

tsconfig.json

@@ -2,6 +2,6 @@
     "compilerOptions": {
         "target": "ES2022",
         "rootDir": "./src",
-        "outDir": "./obj"
+        "outDir": "./build"
     }
 }