com.almworks.jira.structure.api.forest.raw

Interface ForestParentChildrenClosure<T,C>

Type Parameters:

T - the type of the result of processing one row

C - the type of the result of processing a number of sub-rows under the same parent

All Known Implementing Classes:

ForestParentChildrenListClosure

public interface ForestParentChildrenClosure<T,C>

Implement this interface to efficiently process a forest in a bottom-up style with Forest.foldUpwards(com.almworks.jira.structure.api.forest.raw.ForestParentChildrenClosure<T, C>).

Method Summary

Modifier and Type	Method and Description
C	combine(ForestIterationControl fold, T value, C carry) Used to combine values returned by {#visitRow} calls to every sub-row of a single parent.
T	visitRow(ForestIterationControl fold, long row, com.almworks.integers.LongList children, C carry) Process an row using information about children.

Method Detail

combine

@Nullable
C combine(@NotNull
                    ForestIterationControl fold,
                    T value,
                    @Nullable
                    C carry)

Used to combine values returned by {#visitRow} calls to every sub-row of a single parent.

Parameters:

fold - fold control

value - the value returned by visitRow()

carry - the carry value returned by previous call to combine() on a result of processing the successor row under the same parent row, or null for the first call

Returns:

the combined carry value

visitRow

@Nullable
T visitRow(@NotNull
                     ForestIterationControl fold,
                     long row,
                     @NotNull
                     com.almworks.integers.LongList children,
                     @Nullable
                     C carry)

Process an row using information about children.

Parameters:

fold - fold control

row - the row id

children - the sub-rows, or empty list if it's a leaf

carry - the combined carry value (result of calling combine(com.almworks.jira.structure.api.forest.raw.ForestIterationControl, T, C) on every result of child processing, or null if (but not only if) there are no children

Returns:

the result of processing