Flow PHP

Average implements AggregatesNumericTotal, FrameAccumulating, WindowFunction

FinalYes

Interfaces

AggregatesNumericTotal
FrameAccumulating: Asserts the result depends only on frame contents, never on the current row or index.
WindowFunction

Methods

__construct() : mixed
accumulator() : self: A fresh instance with no window, fed the frame's rows through aggregate().
aggregate() : void
children() : array<int, FunctionTree>: Every operand of this node that is an expression, in constructor order.
describe() : null|Description
deterministic() : bool: True when this node and every node in children() produce the same value for the same input row.
exact() : bool
fromDescription() : static
groupValues() : Column
merge() : void: Folds a partial() of another instance into this one; that instance aggregated rows that come after this one's (merge()'s contract).
outputName() : string: Decided in the constructor, never mutated.
over() : static: Returns a copy bound to $window. Never mutates $this.
partial() : array<string, mixed>: This aggregator's state as plain values of partialType(); an aggregator that saw no row returns its initial state.
partialType() : StructureType<string|int, array<string, mixed>>: The structure partial() returns; valid once the aggregator is resolved (Aggregators::resolved()).
references() : array<int, Reference>
resolved() : bool: True when this node and every node in children() can answer returns().
returns() : Type<string|int, mixed>: An OptionalType return declares the produced column nullable; there is no nullable() peer.
toString() : string
value() : null|array<string|int, mixed>|bool|float|int|object|string
values() : array<int, mixed>: One value per row of $partition, which is sorted by the window's ORDER BY.
window() : Window
withChildren() : static: A copy of this node with $children in place of children(): same count, same order, same per-element narrowing. Never mutates $this.

__construct()


    public
                    __construct(Reference $ref[, int $scale = 2 ][, Rounding $rounding = Rounding::HALF_UP ][, bool $exact = false ][, Window|null $window = null ]) : mixed

Parameters

$ref : Reference
$scale : int = 2
$rounding : Rounding = Rounding::HALF_UP
$exact : bool = false
$window : Window|null = null

accumulator()

A fresh instance with no window, fed the frame's rows through aggregate().


    public
                    accumulator() : self

Return values

self

aggregate()


    public
                    aggregate(Rows $rows, array<string|int, mixed> $indices, Backend $backend) : void

Parameters

$rows : Rows
$indices : array<string|int, mixed>: the rows of $rows that belong to this aggregate, ascending
$backend : Backend

children()

Every operand of this node that is an expression, in constructor order.


    public
                    children() : array<int, FunctionTree>

Return values

array<int, FunctionTree>

describe()


    public
                    describe() : null|Description

Return values

null|Description —

null when this instance cannot cross a process boundary (a live client, a custom collaborator)

deterministic()

True when this node and every node in children() produce the same value for the same input row.


    public
                    deterministic() : bool

False for a generator (now(), uuid, a random string): a caller that evaluates the tree once per FILE or per partition instead of once per row must refuse a non-deterministic one.

Return values

bool

exact()


    public
                    exact() : bool

Return values

bool

fromDescription()


    public
            static        fromDescription(array<string|int, mixed> $data, Rebuild $rebuild) : static

Parameters

$data : array<string|int, mixed>
$rebuild : Rebuild

Return values

static

groupValues()


    public
                    groupValues(GroupedTotals $totals, Backend $backend) : Column

Parameters

$totals : GroupedTotals
$backend : Backend

Return values

Column

merge()

Folds a partial() of another instance into this one; that instance aggregated rows that come after this one's (merge()'s contract).


    public
                    merge(array<string|int, mixed> $partial, Backend $backend) : void

Parameters

$partial : array<string|int, mixed>
$backend : Backend

outputName()

Decided in the constructor, never mutated.


    public
                    outputName() : string

Return values

string

over()

Returns a copy bound to $window. Never mutates $this.


    public
                    over(Window $window) : static

Parameters

$window : Window

Return values

static

partial()

This aggregator's state as plain values of partialType(); an aggregator that saw no row returns its initial state.


    public
                    partial() : array<string, mixed>

Return values

array<string, mixed>

partialType()

The structure partial() returns; valid once the aggregator is resolved (Aggregators::resolved()).


    public
                    partialType() : StructureType<string|int, array<string, mixed>>

Return values

StructureType<string|int, array<string, mixed>>

references()


    public
                    references() : array<int, Reference>

Return values

array<int, Reference>

resolved()

True when this node and every node in children() can answer returns().


    public
                    resolved() : bool

Return values

bool

returns()

An OptionalType return declares the produced column nullable; there is no nullable() peer.


    public
                    returns() : Type<string|int, mixed>

Return values

Type<string|int, mixed>

toString()


    public
                    toString() : string

Return values

string

value()


    public
                    value() : null|array<string|int, mixed>|bool|float|int|object|string

Return values

values()

One value per row of $partition, which is sorted by the window's ORDER BY.


    public
                    values(Rows $partition, Backend $backend) : array<int, mixed>

Parameters

$partition : Rows
$backend : Backend

Return values

array<int, mixed>

window()


    public
                    window() : Window

Return values

Window

withChildren()

A copy of this node with $children in place of children(): same count, same order, same per-element narrowing. Never mutates $this.


    public
                    withChildren(array<int, FunctionTree> $children) : static

Parameters

$children : array<int, FunctionTree>

Return values

static