StandingPhase
Exports `standingPhaseOf`, `standingPhaseOfView`, `standingPhaseTagOfStatus`, `standingConditionsOf`, `STANDING_PHASE_TRANSITIONS`, `nextStandingPhase`, `standingTransitionOf`, `STANDING_PHASE_EDGES`.
standingPhaseOf
Kind: Primitive
The phase a standing is in at at.
status alone is not the phase. A trial whose deadline has passed is still
Trialing until PeriodEnded records the close; an active standing past
its period end is still Active; a grace window whose deadline passed is
still Grace. overdue is the clock, and the tag is the log. Reading only
the status hides the window between the two.
Pure: the clock is a parameter, so a console, a test and a replay can ask the same question of the same state.
Reading a phase
const phase = standingPhaseOf(state, at);
// { _tag: "Trialing", deadline: 2030-01-15T00:00:00Z, overdue: true }standingPhaseOfView
Kind: Primitive
The phase of a standing a read model carries. The view has the status and the boundary, so a console can say “the period ended and no close has landed” without holding the aggregate state.
Reading a phase from a billing row
standingPhaseOfView(billing, readAt);
// { _tag: "Active", deadline: 2030-02-01T00:00:00Z, overdue: true }standingPhaseTagOfStatus
Kind: Primitive
The phase tag a status alone names. A read model that has no clock can still
say which phase it is in; overdue needs standingPhaseOfView.
Classifying a status
standingPhaseTagOfStatus("grace"); // "Grace"standingConditionsOf
Kind: Primitive
The orthogonal state a standing carries beside its phase.
The phase says where the lifecycle is; these say what the next command will find when it gets there. A pending tier on an expired standing, a cooldown whose deadline passed, a hold past its expiry and a proration credit with no consumer are all visible here instead of being inferred from absent fields.
Reading what the next command will see
const conditions = standingConditionsOf(state, at);
// { pendingTier: "pro", topUpCooldown: "lapsed", lapsedHolds: 1, ... }STANDING_PHASE_TRANSITIONS
Kind: Primitive
Every phase under every move. A total table, not a sparse edge list: a move
that cannot happen is a self-edge, so a reader can ask [phase][move]
instead of replaying a chain of guards. The shape is Alchemy’s
SQLITE_TRANSITIONS table in @alchemy.run/sql/SqlFile: every state has
every token and the runner is a single index.
The surprising cells are the honest ones. Active + trial -> Trialing is
reachable because StartTrial guards on trialUsed, not on the standing
already being open; Expired + activate -> Active is how a payment
reactivates a terminal account. Anything a later guard refuses becomes a
self-edge here, which is the same edit as changing the guard.
nextStandingPhase
Kind: Primitive
The phase tag one move leaves behind. Total in both arguments: an impossible
move answers the same tag, so a caller never has to handle undefined just
because the standing refused the command.
Asking the table
nextStandingPhase("Grace", "expire"); // "Expired"
nextStandingPhase("Active", "expire"); // "Active"standingTransitionOf
Kind: Primitive
The move a command names, as the table’s second key.
A close is the one command whose move depends on the standing: with a
cancellation scheduled it is cancelAtBoundary, otherwise close. Every
other command is classified by its tag alone; a command that only touches
counters, credits or refs is other, which is a self-edge in every phase.
A command that records nothing — an early PeriodEnded, a repeat Expire
— is not a move. The table classifies what a decision did, so a caller
holding an empty decision stays on the same phase without consulting it.
Classifying a close
standingTransitionOf({ _tag: "PeriodEnded" }, { ...state, cancelAtPeriodEnd: true });
// "cancelAtBoundary"STANDING_PHASE_EDGES
Kind: Primitive
The annotated view of STANDING_PHASE_TRANSITIONS: one row per pair of
phases the table can reach (including each phase’s self-edge), with the
commands that take it and the notes a reader needs. The table is the source of truth; this list is how a
human reads it, and test/standing/Phase.test.ts holds the two together.