def scan.loop

mylsm-lsm-store@0.6.0.1 · src/scan/SstCursor.bend:222

import Base
import mylsm-lsm-store@0.6.0.1/src/scan/ByteBlockReader.bend as ByteBlockReader

222def scan.loop(fuel: Nat, state: ScanState) -> IO(Step):
223  match fuel:
224    case 0n: scan.exhausted(state)
225    case 1n+rest:
226      match state:
227        case ScanNeed{reader, bounds}:
228          do IO<Step>:
229            result : Result<&1, &1, U32 & String, ByteBlockReader.Step> <-
230              ByteBlockReader.next(reader)
231            scan.loop(rest, ScanRead{result, bounds})
232        case ScanRead{result, bounds}:
233          match result:
234            case Fail{error}:
235              IO.pure(Step, Error{error})
236            case Done{ByteBlockReader.End{}}:
237              IO.pure(Step, End{})
238            case Done{ByteBlockReader.Block{reader, entries}}:
239              scan.loop(rest, ScanBlock{reader, entries, bounds})
240        case ScanBlock{reader, entries, bounds}:
241          match entries:
242            case Nil{}:
243              scan.loop(rest, ScanNeed{reader, bounds})
244            case Con{entry, tail}:
245              scan.entry(entry, ByteBlockReader.EntryReady{reader, tail}, bounds)