{"id":5224,"date":"2024-06-13T09:49:21","date_gmt":"2024-06-13T07:49:21","guid":{"rendered":"https:\/\/oopm.org\/?page_id=5224"},"modified":"2025-01-14T13:50:23","modified_gmt":"2025-01-14T12:50:23","slug":"5224-2","status":"publish","type":"page","link":"https:\/\/oopm.org\/?page_id=5224","title":{"rendered":"10.2.2 Status of flights"},"content":{"rendered":"
\"image_pdf\"<\/a>\"image_print\"<\/a><\/div>\n

In order to provide status on flights, we extend the first definition of class Flight<\/code> with a couple of data-items, and later by some methods that provide the status:<\/p>\n\n\n\n

   class<\/strong> FlightRoute(FlightNumber, origin, destination: var<\/strong> String):   \n      scheduledDepartureTime: var<\/strong> TimeOfDay \n      scheduledArrivalTime: var<\/strong> TimeOfDay <\/mark>\n      -\"-\n      class<\/strong> Flight(departureDate: var<\/strong> Date<\/mark>):  <\/mark> \n         departureTime: var<\/strong> TimeOfDay  \n         arrivalTime: var<\/strong> TimeOfDay:\n         flightTime: -> ft: var<\/strong> Time.Hours\n            ft := arrivalTime - departureTime\n         delayed: var<\/strong> Boolean\n         delayDeparture(newTime: var<\/strong> TimeOfDay):\n            -- this is called in case the departure is delayed\n            delayed := True\n            departureTime := newTime\n         delay -> period: var<\/strong> Time.Hours:\n            period := arrivalTime \u2013 scheduledArrivalTime\n\n         cancelled: var<\/strong> Boolean\n         cancel:\n            cancelled := True\n         hasArrived: var<\/strong> Boolean\n         hasTakenOff: var<\/strong> Boolean <\/code><\/pre>\n\n\n\n
In the event of cancellation, the method cancel<\/code> is called.<\/p>\n\n\n\n
At take off, departureTime<\/code> is set to the time of take off, hasTakenOff<\/code> is set to True<\/code>, and hasArrived<\/code> is set to False<\/code>. While flying the attribute arrivalTime<\/code> is set based on weather condition and the landing condition of the destination airport. It is therefore assumed that this is set based on real time information from the plane. At arrival, hasArrived<\/code> is set to True<\/code> and hasTakenOff<\/code> to False<\/code>.<\/p>\n\n\n\n
Status of flights are provided in two different ways, either given the origin\/destination airport at a given date, or given the name of the flight route, e.g. SK1926.<\/p>\n\n\n\n
The method departureStatus<\/code> defined below is called with some interval before take off, to provide the status text that may be displayed:<\/p>\n\n\n\n
class<\/strong> Flight(departureDate: var<\/strong> Date<\/mark>):\n   -\"-\n   departureStatus -> info: var<\/strong> String:  \n      info := (\"Flight \" + FlightNumber + \" at: \" + departureDate.asString)\n      if cancelled :then\n         info := info + \"is cancelled\"\n      :else\n         if delayed :then\n            info := info + \"Estimated departure time: \"+ \n                    departureTime +\n                    \" expected arrival time: \" + \n                    (departureTime + flightTime)\n         :else\n            info := info + \" On schedule: \" + \n                    scheduledDepartureTime.t.magnitude<\/code><\/pre>\n\n\n\n
The next method is called after take off:<\/p>\n\n\n\n
class<\/strong> Flight(departureDate: var<\/strong> Date<\/mark>): \n   -\"-\n   arrivalStatus -> info: var<\/strong> String:  \n      info := (\"Flight \" + name + \" at: \" + departureDate.asString)\n      info := info + \"Departed at: \"+ departureTime\n      if (not hasArrived) :then         info := info + \" expected at: \" + arrivalTime<\/code>      :else\n<\/mark>         info := info + \" arrived at: \" + ArrivalTime + \n                 \" delayed: \" + delay<\/code><\/pre>\n\n\n\n
Given the above status methods in Flight<\/code>, we have three ways of selection which flights we want the status: for all flights in all flight routes of a time table, for flights departing or arriving from a given airport at a given date, or flights of a given route at a given airport and date.<\/p>\n\n\n\n
Status of flights in the time table<\/h4>\n\n\n\n
Based upon the entries in the time table, flight status for all flights is provided by the following method:<\/p>\n\n\n\n
showFlightStatus:\n   timeTable.scanTimeTable\n      fr: ref<\/strong> FlightRoute \n      fr := current \n      fr.scan\n         if (not hasTakenOff) :then \n            currentFlight.departureStatus.print\n         :else\n            currentFlight.arrivalStatus.print\n         newline\t<\/code><\/pre>\n\n\n\n
The method showFlightStatus<\/code> is a submethod of the method scanTimeTable<\/code> in timeTable<\/code>. The method scanTimeTable<\/code> scans the entries<\/code> list of FlightRoute<\/code> objects; for each FlightRoute<\/code>, held by fr,<\/code> a singular method being a submethod of fr.scan<\/code> scans the Flight<\/code> objects of the flights<\/code> list in the FlightRoute<\/code> held by fr<\/code>.<\/p>\n\n\n\n
As described above, the method showFlightStatus<\/code>   is based upon a scanTimeTable<\/code> method in timeTable<\/code>:<\/p>\n\n\n\n
timeTable: obj<\/strong>\n   entries: obj<\/strong> OrderList(FlightRoute)\n   scanTimeTable:\n      current: ref<\/strong> FlightRoute\n      entries.scan\n          this(scanTimeTable).current := current\n          inner(scanTimeTable)<\/code><\/pre>\n\n\n\n
As explained before, the inner(scanTimeTable)<\/code> is executed for each element in entries<\/code>, and what is executed is the statements of the showFlightStatus<\/code> submethod of timeTable.scanTimeTable<\/code><\/p>\n\n\n\n
The above is in turn based upon a scan<\/code> method of FlightRoute<\/code>, scaning all the Flight<\/code> objects of the list flights<\/code>:<\/p>\n\n\n\n
class<\/strong> FlightRoute(flightNumber, origin, destination: var<\/strong> String):   \n   -\"-\n   scan:\n       currentFlight: ref<\/strong> Flight\n       flights.scan\n          currentFlight := current\n          inner(scan)<\/code><\/pre>\n\n\n\n
From\/to a given airport, at a given date<\/h4>\n\n\n\n
The following method delivers the list of flights <\/mark>from a given <\/mark>airport at a given date:<\/p>\n\n\n\n
fromAirport(ap: var<\/strong> String, d: var<\/strong> Date) \n   -> flights: ref<\/strong> OrderedList(Flight):\n\n   timeTable.routesFrom(ap).scan\n      current.flights.scan\n         if (current.date = d) :then \n            flights.insert(current)<\/code><\/pre>\n\n\n\n
This is based upon the method routesFrom<\/code> in timeTable<\/code>, delivering the list of routes departing from a given airport:<\/p>\n\n\n\n
timeTable: obj<\/strong>\n   -\"-\n   routesFrom(ap: var<\/strong> String) -> routes: OrderedList(FlightRoute):\n      entries.scan\n      if (current.origin = ap :then \n         routes.insert(current)<\/code><\/pre>\n\n\n\n
It is left as a simple exercise to make the method that delivers the list of flights <\/mark>to <\/mark>a given destination airport at a given date.<\/p>\n\n\n\n
Answer:<\/p>\n\n\n\n
toAirport(ap: var String, d: var<\/strong> Date) \n   -> flights: ref<\/strong> OrderedList(Flight):\n   timeTable.routesTo(ap).scan\n      current.flights.scan\n         if (current.date = d) :then \n            flights.insert(current)<\/code><\/pre>\n\n\n\n
based upon:<\/p>\n\n\n\n
timeTable: obj<\/strong>\n   -\"-\n   routesTo(ap: var<\/strong> String) -> routes: OrderedList(FlightRoute):\n      entries.scan\n      if (current.destination = ap :then \n         routes.insert(current)<\/code><\/pre>\n\n\n\n
Before the list of Flight<\/code> objects delivered by these two methods are used for producing the status website, the list delivered by fromAirport<\/code> should be sorted according to departure time, while the list of Flight<\/code> objects delivered by toAirport<\/code> should be sorted according to arrival time.<\/p>\n\n\n\n
Given these two lists of Flight<\/code> objects, the status website can produce the two strings delivered by the methods departureStatus<\/code> and arrivalStatus<\/code>.<\/p>\n\n\n\n
fromAirport(\"OSL\", Date(6, 6, 2024)).scan\n   current.departureStatus.print \nfromAirport(\"OSL\", Date(6, 6, 2024)).scan\n   current.arrivalStatus.print \n\nfromAirport(\"ARR\", Date(6, 6, 2024)).scan\n   current.departureStatus.print \nfromAirport(\"ARR\", Date(6, 6, 2024)).scan\n   current.arrivalStatus.print <\/code><\/pre>\n\n\n\n
Given the flight number, airport, and a given date<\/h4>\n\n\n\n
The following method produces the list of flights given a certain route, from a given airport at a certain date:<\/p>\n\n\n\n
onFlightNumberFrom(fn: var<\/strong> String, from: var<\/strong> String d: var<\/strong> Date)\n   -> flights: ref<\/strong> OrderedList(Flight):\n   theRoute: ref<\/strong> FlightRoute\n   theRoute := timeTable.lookupRoute(fn)\n   if theRoute.origin = from :then\n      theRoute.flights.scan\n         if (current.date = d) :then flights.insert(current)<\/code><\/pre>\n\n\n\n
This is based on a simple lookupRoute<\/code> in TimeTable<\/code>:<\/p>\n\n\n\n
timeTable: obj<\/strong>\n   entries: obj<\/strong> OrderList(FlightRoute)\n   scanTimeTable:\n      current: ref<\/strong> FlightRoute\n      entries.scan\n          this(scanTimeTable).current := current\n          inner(scanTimeTable)<\/mark>\n\n   <\/mark>lookupRoute(fn: var<\/strong> String) -> theRoute: ref<\/strong> FlightRoute: scanTimeTable\n      if current.flightNumber = fn :then\n         theRoute := current\n         leave(lookupRoute) <\/code><\/pre>\n\n\n\n
It is left as a simple exercise to make the method that produces the list of flights given a certain route, to a given airport at a certain date:<\/p>\n\n\n\n
Answer:<\/p>\n\n\n\n
onFlightNumberTo(fn: var<\/strong> String, to: var<\/strong> String d: var<\/strong> Date)\n   -> flights: ref<\/strong> OrderedList(Flight):\n   theRoute: ref<\/strong> FlightRoute\n   theRoute := timeTable.lookupRoute(fn)\n   if theRoute.destination = to :then\n      theRoute.flights.scan\n         if (current.date = d) :then flights.insert(current)<\/code><\/pre>\n\n\n\n
Given these two lists of Flight<\/code> objects, the status website can produce the two strings delivered by the methods departureStatus<\/code> and arrivalStatus<\/code>.<\/p>\n\n\n\n
onFlightNumberFrom(\"SK1926\", \"ARR\" Date(6, 6, 2024)).scan\n   current.departureStatus.print \nonFlightNumberTo(\"SK1926\", \"OSL\" Date(6, 6, 2024)).scan\n   current.arrivalStatus.print <\/code><\/pre>\n\n\n\n
<\/p>\n
\n\t\t<\/a>\n\t\t<\/div>","protected":false},"excerpt":{"rendered":"
In order to provide status on flights, we extend the first definition of class Flight with a couple of data-items, and later by some methods that provide the status: In the event of cancellation, the method cancel is called. At take off, departureTime is set to the time of take off, hasTakenOff is set to […]<\/p>\n","protected":false},"author":3,"featured_media":0,"parent":5004,"menu_order":3,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-5224","page","type-page","status-publish","hentry"],"mb":[],"mfb_rest_fields":["title","gutenberg_elementor_mode"],"_links":{"self":[{"href":"https:\/\/oopm.org\/index.php?rest_route=\/wp\/v2\/pages\/5224","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/oopm.org\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/oopm.org\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/oopm.org\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/oopm.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=5224"}],"version-history":[{"count":48,"href":"https:\/\/oopm.org\/index.php?rest_route=\/wp\/v2\/pages\/5224\/revisions"}],"predecessor-version":[{"id":11119,"href":"https:\/\/oopm.org\/index.php?rest_route=\/wp\/v2\/pages\/5224\/revisions\/11119"}],"up":[{"embeddable":true,"href":"https:\/\/oopm.org\/index.php?rest_route=\/wp\/v2\/pages\/5004"}],"wp:attachment":[{"href":"https:\/\/oopm.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5224"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}