Function unsafeUpdateAs

packages/effect/src/internal/fiberRefs.ts:221–252

(
  locals: Map<FiberRef.FiberRef<any>, Arr.NonEmptyReadonlyArray<readonly [FiberId.Single, any]>>,
  fiberId: FiberId.Single,
  fiberRef: FiberRef.FiberRef<any>,
  value: any
)

})

const unsafeUpdateAs = (
  locals: Map<FiberRef.FiberRef<any>, Arr.NonEmptyReadonlyArray<readonly [FiberId.Single, any]>>,
  fiberId: FiberId.Single,
  fiberRef: FiberRef.FiberRef<any>,
  value: any
) => {
  const oldStack: ReadonlyArray<readonly [FiberId.Single, any]> = locals.get(fiberRef) ?? []
  let newStack: Arr.NonEmptyReadonlyArray<readonly [FiberId.Single, any]> | undefined

  if (Arr.isNonEmptyReadonlyArray(oldStack)) {
    const [currentId, currentValue] = Arr.headNonEmpty(oldStack)
    if (currentId[Equal.symbol](fiberId)) {
      if (Equal.equals(currentValue, value)) {
        return
      } else {
        newStack = [
          [fiberId, value] as const,
          ...oldStack.slice(1)
        ]
      }
    } else {
      newStack = [
        [fiberId, value] as const,
        ...oldStack
      ]
    }
  } else {
    newStack = [[fiberId, value] as const]
  }

  locals.set(fiberRef, newStack)
}

/** @internal */
export const updateManyAs = dual<