====== Data Query / Expression Language ======

===== Links =====
  * [[https://nexus.exalead.com/repository/public-site/dse-best-practice/01-BestPractices/02-DataPerspectiveStudio/02-DataQueries/04-ExpressionLanguage/01-Content/|NETVIBES Consulting - DSE Best Pratices / Expression Language]]
  * [[https://help.3ds.com/2025x/english/DSDoc/DaaUserMap/daa-m-appendix-expression-language-sb.htm?contextscope=cloud&id=59de7db3d7e3457485b3af4910de8979|DS Doc - Expression Language]]

===== Examples =====
==== Divers ====

<code>
transitionTuples : List<Tuple<event: String, datetime: DateTime, current: String>> = 
    List.range(startInclusive: 0, endExclusive: issue._history_event.length, step: 1 )
        .map(index => issue._history_event[index] IN ["create", "promote","demote"]? 
            {event:issue._history_event[index], datetime:issue._history_time[index],current:issue._history_state[index]}
            :NULL
        ).filter(x => x IS NOT NULL);

</code>

<code>
durationsByTransition : List<Tuple<state: String, duration: Integer>> =
    List.range(startInclusive: 1, endExclusive: transitionTuples.length, step: 1 )
        .map(index =>{state: transitionTuples[index - 1].current, duration: Date.daysBetween(start: transitionTuples[index - 1].datetime, end: transitionTuples[index].datetime)})
    + {state: transitionTuples[transitionTuples.length - 1].current, duration:Date.daysBetween(start: transitionTuples[transitionTuples.length - 1].datetime, end: Date.today())};
</code>

====  stateful map() ====

<code>
snapshotTuples : List<Tuple<week: String, current: String>> = 
    $Year_Weeks
        .map(
            initialState: issue.current
            , updateState: (x, previousState) => transitionsMap[x].current IS NOT NULL?transitionsMap[x].current:previousState
            , function: (x, currentState) => {week:x, current:x>=originatedWeek?currentState:NULL}
        )
        .filter(x => x.current IS NOT NULL);
</code>

==== toMap ====

<code>
transitionsMap : Map<String, Tuple<event: String, datetime: DateTime, current: String>> =
    List.range(startInclusive: 0, endExclusive: issue._history_event.length, step: 1 )
        .map(index => issue._history_event[index] IN ["create", "promote","demote"]?
            {event: issue._history_event[index], datetime:issue._history_time[index], current: issue._history_state[index]}
            :NULL)
        .filter(x => x IS NOT NULL)
        .toMap(
            keyFunction: x => Date.format(date: x.datetime, format:"yyyy_ww")
            , valueFunction: x => x
        );
</code>
==== Map.mapValues ====

//allDurationsByStatus// : Map<String, List<Tuple<state: String, duration: Integer>>>

<code>
durationsByStatus : Map<String, Integer> =
    Map.mapValues(
        map: allDurationsByStatus
        , function: (list => list.sum(x => x.duration))
    )
;
</code>

ou 

<code>
durationsByStatus : Map<String, Integer> =
    allDurationsByStatus.mapValues(list => list.sum(x => x.duration));
</code>