Module output_channel 

SRD-87 Output Channel — the single typed terminal-output conduit.

Push 1 lands the trait, the op-output bucket, and a test-capture impl. Every adapter op line submits through OutputChannel::op_output; the installed impl alone decides where the bytes land. The remaining buckets (log / status / raster) and the consolidation of RunObserver + DisplaySink arrive in later pushes (SRD-87 §11/§13).

The op-output channel is selected once per run from the run’s context (silent_console, is_tty) — replacing the prior console_reserved_for_adapter global flag that op_output consulted inline. A console-owning adapter (silent_console) and a piped run both own a raw stdout surface; an interactive dashboard routes op output through the live display so it composites without the raw-mode staircase. The console-owning stdout adapter printing nothing on a TTY (the SRD-87 §2 defect) falls out as a consequence: under the raw impl the op line is the adapter’s, written to the surface it owns, never suppressed alongside the diagnostics.

Structs

CaptureChannel

Test-capture impl: records every op-output line for assertions and writes no fd. The SRD-87 §12 surface-agreement / no-bypass tests install one of these and inspect Self::op_lines.

DisplayRoutedChannel

op-output routed through the live display: the active LogOnlySink / TuiSink composites the line into its scrollback, avoiding the raw-mode staircase. Selected for an interactive dashboard that is not console-owning (tui=terminal / on).

RawStdoutChannel

op-output written raw to the stdout the producer owns, plus a durable session.log capture. Selected for a console-owning adapter on a TTY (it owns the screen) AND for a piped/redirected run (so nmbrs run | grep and > file keep working). This is the impl that makes a console-owning stdout adapter actually print: the line is the adapter’s, written to the surface it owns, never suppressed with the diagnostics.

Enums

ChannelKind

Which op-output impl a run’s context selects (SRD-87 §10). Factored out so the selection is unit-testable without standing up a surface.

Traits

OutputChannel

The single conduit for the one user terminal. Exactly one impl is installed per run via install; producers submit to a bucket and only the impl touches an fd. Every method is non-blocking.

Functions

clear

Clear the installed channel (end of run; tests).

install

Install the op-output channel for this run (SRD-87 §10 — chosen once per context). Replaces any prior install.

installed

The installed channel, if any. SRD-88 — task-local-first: a concurrent in-process execution that scoped its own channel (ExecutionContext.channel) resolves to it; everything else (single-run, bootstrap, tests) falls back to the process-global CHANNEL (axiom A1, a true no-op until a context scopes one).

log_to_surface

Project a diagnostic line to the log bucket (the live terminal). Called by observer::log_categorized/the observer impls after the L1 intake (session.log + fold ring) and after the sink_active/min_level gate has decided the line should reach the live surface (SRD-87 §5). Routes to the installed channel — the sole fd owner — falling back to a direct colorized stderr write before any channel is installed (bootstrap), so behavior is unchanged.

raster

Submit a raster frame (a self-contained, pre-rendered terminal canvas) to the channel. Producers — the plotter — call this instead of print!-ing the frame themselves (SRD-87 §5). Routes to the installed channel (the fd owner), falling back to a raw stdout write before any channel is installed (bootstrap / unit tests), so behavior is unchanged.

select

Build the op-output channel a run’s context selects.

select_kind

The op-output routing a run’s context implies. A console-owning adapter (silent_console) owns a raw surface; a piped run (!is_tty) owns the pipe; only an interactive dashboard routes through the display.