Effect CommunityEC
Effect Community•10mo ago
Kedi

Compositional Resource Management Pattern for Dependent Lifetimes in TypeScript

How to model dependent resource lifetimes compositionally (not imperatively) to avoid callback hell while ensuring proper cleanup?
I'm processing a chain of resources where each step depends on the previous output (e.g., src → processedMat → paddedMat →), and each resource requires cleanup. Using nested acquireUseRelease blocks quickly becomes unwieldy. What pattern or abstraction can I use to manage these dependent resources linearly (without deep nesting) while ensuring:

1. Automatic cleanup of intermediate resources
2. Composability for operations like cv.cvtColor or padImage that produce new resources (if they allocate internally).

Example of the problem: 
// Current nested structure (simplified)
const paddedMat = yield* E.acquireUseRelease(
E.succeed(cv.matFromImageData(
    new ImageData(
    new Uint8ClampedArray(obj),
    imageBitmap.width,
    imageBitmap.height,
    ),
)),
(src) =>
    E.acquireUseRelease(E.succeed(new cv.Mat()), (processedMat) =>
    E.succeed(processedMat).pipe(
        E.tap((processedMat) =>
        // Convert color space from RGBA to RGB
        cv.cvtColor(src, processedMat, cv.COLOR_RGBA2RGB)
        ),
        E.andThen(padImage),
    ), (processedMat) => E.sync(processedMat.delete)),
(src) =>
    E.sync(src.delete),
);
// How to manage `paddedMat` cleanup without nesting further?


Desired Pseudo-Code 
// How to model this with a clean, flat structure?
const paddedMat = yield* withResource(src, (src) => 
  withResource(processedMat, (processedMat) => 
    cv.cvtColor(src, processedMat, ...),
    padImage(processedMat) // Returns paddedMat
  )
);
// All resources (src, processedMat, paddedMat) are automatically tracked and released.
Was this page helpful?