open System
open System.IO
open System.Threading
open System.Threading.Tasks
open Axial
open Axial.Console
open Axial.FileSystem
open Axial.PlatformService
open Axial.Process

Streaming output

Use Process.stream when a process's output is part of the workflow, rather than something to inspect after the process exits. It returns a FlowStream, not a Flow.

let events =
    Process.command $"device-tool watch"
    |> Process.framing OutputFraming.Lines
    |> Process.stream

With OutputFraming.Lines, each ProcessEvent.Output contains one decoded line. OutputFraming.Chunks preserves arbitrary decoded chunks. Every output value identifies its stage, stdout or stderr channel, and timestamp. The final event is always ProcessEvent.Completed result.

Handle events as they arrive

Use ordinary FlowStream combinators to take, filter, transform, or collect events:

let report event =
    match event with
    | ProcessEvent.Output output -> printfn "[%A] %s" output.Channel output.Text
    | ProcessEvent.Completed result -> printfn "exit code: %d" result.ExitCode

let! collected =
    Process.command $"device-tool watch"
    |> Process.framing OutputFraming.Lines
    |> Process.stream
    |> FlowStream.runCollect

collected |> List.iter report

The stream is backpressured: Axial does not buffer unbounded events while the consumer is busy. Stopping consumption early interrupts the producer Flow and terminates the native process topology before the enclosing scope closes.

Stream versus console forwarding

Use DSL console, or configure both channels with Process.stdout and Process.stderr, when output only needs to be visible. That path returns a normal Flow that completes with ProcessResult. Use Process.stream when output itself drives workflow decisions.