effect-resource-management

# Effect Resource Management

Master automatic resource management in Effect using Scopes and finalizers.
This skill covers resource acquisition, cleanup, scoped effects, and patterns
for building leak-free Effect applications.

## Scope Fundamentals

A Scope represents the lifetime of resources. When a scope closes, all
registered finalizers execute automatically.

### Basic Scope Usage

```typescript
import { Effect, Scope } from "effect"

const program = Effect.scoped(
  Effect.gen(function* () {
    // Resources acquired here are tied to this scope
    const resource = yield* acquireResource()

    // Use resource
    const result = yield* useResource(resource)

    return result
    // Scope closes here, resources cleaned up automatically
  })
)
```

### Adding Finalizers

```typescript
import { Effect } from "effect"

const acquireFile = (path: string) =>
  Effect.gen(function* () {
    // Acquire resource
    const file = yield* Effect.sync(() => openFile(path))

    // Register cleanup
    yield* Effect.addFinalizer(() =>
      Effect.sync(() => {
        console.log(`Closing file: ${path}`)
        file.close()
      })
    )

    return file
  })

// Usage
const program = Effect.scoped(
  Effect.gen(function* () {
    const file = yield* acquireFile("data.txt")
    const content = yield* readFile(file)
    return content
    // File automatically closed on scope exit
  })
)
```

## Finalizer Behavior

### Execution Order

Finalizers execute in reverse order of registration (LIFO):

```typescript
import { Effect } from "effect"

const program = Effect.scoped(
  Effect.gen(function* () {
    yield* Effect.addFinalizer(() =>
      Effect.log("Finalizer 1")
    )

    yield* Effect.addFinalizer(() =>
      Effect.log("Finalizer 2")
    )

    yield* Effect.addFinalizer(() =>
      Effect.log("Finalizer 3")
    )

    return "done"
  })
)
// Output:
// Finalizer 3
// Finalizer 2
// Finalizer 1
```

### Exit Information

Finalizers receive exit information:

```