:: a typeCtrl KGHC 9.10.3
Modulevortex-trace-0.4.0GHC2024
The observable vocabulary. A block's externally visible behaviour
is a finite sequence of Said emissions terminated by exactly one
Result or Failed; nothing else about evaluation is observable.
The wire protocol is show of Reply, one frame per value — Haskell
on the wire, recovered client-side with readMaybe.
A verb may instead open a duplex channel (Duplexing), after which the call carries a StreamElem of chunks in each direction — the primitive behind streaming verbs like git. The stream's trailer is an ordinary Reply, so a plain text verb is just a stream with no chunks.
Said StringA line the block spoke while running (streamed as it happens).
Result StringThe block finished; its value, show-rendered.
Failed StringThe block did not compile, ran out of fuel, or threw.
DuplexingThe call is now a duplex byte channel: after this reply, frames on
the call carry StreamElem Reply chunk in each direction, the
terminating StreamElem bearing the closing Result or Failed.
An element positioned in a stream, generic over the chunk type a and
the trailer type b (for a duplex vortex call, a is a raw chunk and b
is the closing Reply). The trailer is carried by the terminal
constructors, so end-of-stream is never a content-less token. Two terminal
forms because the end may arrive fused with the last chunk (FinalElem) or
separately after it (StreamElem then NoMoreElems) — a reader cannot know
a chunk is the last until it reads past it. (The shape is grapesy's
StreamElem; the transport is vortex's own, not gRPC.)
StreamElem !aA chunk; more follow.
FinalElem !a !bThe last chunk, fused with the trailer.
NoMoreElems !bNo (more) chunks; just the trailer.
Functor (StreamElem b)Defined in vortex-trace-0.4.0 · Vortex.TraceFoldable (StreamElem b)Defined in vortex-trace-0.4.0 · Vortex.TraceTraversable (StreamElem b)Defined in vortex-trace-0.4.0 · Vortex.Trace(Eq a, Eq b) => Eq (StreamElem b a)Defined in vortex-trace-0.4.0 · Vortex.Trace(Read a, Read b) => Read (StreamElem b a)Defined in vortex-trace-0.4.0 · Vortex.Trace(Show a, Show b) => Show (StreamElem b a)Defined in vortex-trace-0.4.0 · Vortex.TraceWhere a running block's Said output goes: stdout for a REPL, a transport frame for a connected wisp.
One operation a wisp may call, for capability discovery: the name,
its normalised signature, an optional doc, and the theories it uses.
Reflected from the DSL's export list, so it is exactly the granted
surface. A client gets [Command] back from :commands as
show-rendered Haskell (in a Result), readable with
readMaybe — so an agent learns the whole typed API in one
round trip.
CommandcommandName :: StringcommandType :: StringcommandDoc :: Maybe StringcommandEffects :: [String]The theories named by the Member and Members constraints of the
reflected type, unqualified, in the order written and without
repeats (["Projects"], ["Error NixLabError"]). Empty when
the type has no such constraint: a pure function, or a verb at the
shell's whole monad.
Eq CommandDefined in vortex-trace-0.4.0 · Vortex.TraceRead CommandDefined in vortex-trace-0.4.0 · Vortex.TraceThe derived reading, which also accepts the three-field record a 0.2.0 host sends (with no effects), so a client reads a host that predates the field during a deploy.
Show CommandDefined in vortex-trace-0.4.0 · Vortex.TraceOne operation by name, its arguments as show-rendered Haskell values: the wire form of a call for peers that do not elaborate. A shell dispatches it from its table; the reply is the same Reply stream a block produces. This is the D-Bus method call of the stack — and, unlike a block, it needs no GHC on the far side.