nim-codex/codex/purchasing/purchase.nim

44 lines
1.0 KiB
Nim

import ./statemachine
import ./states/pending
import ./purchaseid
# Purchase is implemented as a state machine:
#
# pending ----> submitted ----------> started
# \ \ \
# \ \ -----------> cancelled
# \ \ \
# --------------------------------------> error
#
export Purchase
export purchaseid
func newPurchase*(request: StorageRequest,
market: Market,
clock: Clock): Purchase =
Purchase(
future: Future[void].new(),
request: request,
market: market,
clock: clock
)
proc start*(purchase: Purchase) =
purchase.switch(PurchasePending())
proc wait*(purchase: Purchase) {.async.} =
await purchase.future
func id*(purchase: Purchase): PurchaseId =
PurchaseId(purchase.request.id)
func finished*(purchase: Purchase): bool =
purchase.future.finished
func error*(purchase: Purchase): ?(ref CatchableError) =
if purchase.future.failed:
some purchase.future.error
else:
none (ref CatchableError)