FlattenReduceCallback<T> typedef
FlattenReduceCallback<T> =
T? Function(T? previousValue, Feature<GeometryObject> currentFeature, int featureIndex, int multiFeatureIndex)
Callback for flattenReduce
The first time the callback function is called, the values provided as
arguments depend on whether the reduce method has an initialValue
argument.
If an initialValue
is provided to the reduce method:
- The
previousValue
argument is initialValue. - The
currentValue
argument is the value of the first element present in the List. If aninitialValue
is not provided: - The
previousValue
argument is the value of the first element present in the List. - The
currentValue
argument is the value of the second element present in the List.
flattenReduceCallback
previousValue
is the accumulated value previously returned in the
last invocation of the callback, or initialValue
, if supplied.
currentFeature
is the current Feature being processed.
featureIndex
is the current index of the Feature being processed.
multiFeatureIndex
is the current index of the Multi-Feature being
processed.
Implementation
typedef FlattenReduceCallback<T> = T? Function(T? previousValue,
Feature currentFeature, int featureIndex, int multiFeatureIndex);