Go-style error handling

const program = Effect.gen(function*() {
  const myurl = new URL("https://example.com/?activeTab=RUN_SEQ__2")

  const runSeq = yield* Effect.gen(function*() {
    const activeTab = myurl.searchParams.get("activeTab")
    if (!activeTab) return yield* new UrlError()
    const runSeqString = activeTab.match(/^RUN_SEQ__([0-9]+)$/)?.[1]
    if (!runSeqString) return yield* new UrlError()
    const runSeq = Number.parse(runSeqString)
    if (Option.isNone(runSeq)) return yield* new UrlError()
    return runSeq.value
  })

  return runSeq
})