Function go

packages/effect/src/internal/channel.ts:1686–1769

(
        state: State
      )

      }

      function go(
        state: State
      ): Channel.Channel<
        OutElem | OutElem1,
        unknown,
        OutErr2 | OutErr3,
        unknown,
        OutDone2 | OutDone3,
        unknown,
        Env | Env1
      > {
        switch (state._tag) {
          case MergeStateOpCodes.OP_BOTH_RUNNING: {
            const leftJoin = Effect.interruptible(Fiber.join(state.left))
            const rightJoin = Effect.interruptible(Fiber.join(state.right))
            return unwrap(
              Effect.raceWith(leftJoin, rightJoin, {
                onSelfDone: (leftExit, rf) =>
                  Effect.zipRight(
                    Fiber.interrupt(rf),
                    handleSide(leftExit, state.right, pullL)(
                      options.onSelfDone,
                      mergeState.BothRunning,
                      (f) => mergeState.LeftDone(f)
                    )
                  ),
                onOtherDone: (rightExit, lf) =>
                  Effect.zipRight(
                    Fiber.interrupt(lf),
                    handleSide(rightExit, state.left, pullR)(
                      options.onOtherDone as (
                        ex: Exit.Exit<OutDone1, InErr1 | OutErr1>
                      ) => MergeDecision.MergeDecision<
                        Env1 | Env,
                        OutErr,
                        OutDone,
                        OutErr2 | OutErr3,
                        OutDone2 | OutDone3
                      >,
                      (left, right) => mergeState.BothRunning(right, left),
                      (f) => mergeState.RightDone(f)
                    )
                  )
              })
            )
          }
          case MergeStateOpCodes.OP_LEFT_DONE: {
            return unwrap(
              Effect.map(
                Effect.exit(pullR),
                Exit.match({
                  onFailure: (cause) => core.fromEffect(state.f(Exit.failCause(cause))),
                  onSuccess: Either.match({
                    onLeft: (done) => core.fromEffect(state.f(Exit.succeed(done))),
                    onRight: (elem) =>
                      core.flatMap(
                        core.write(elem),
                        () => go(mergeState.LeftDone(state.f))