Windows over a feed's window field (spec/08 §11.2, D-140, D-154).
A window is nil — whatever a feed holds — or [from, to], either bound nil for
open. Its bounds are values of the feed's window field: numbers for a :number field,
or instants — DateTime, NaiveDateTime or Date values — for a :time one, a window
and a column of one kind (applies?/2). These are the
comparisons, the trim and the numeric position that Visualize.Feed.finish/3,
Visualize.Feed.Monitor and Visualize.Feed.Combine share.
Examples
iex> Visualize.Feed.Window.within?(5, [0, 10])
true
iex> Visualize.Feed.Window.within?(~U[2026-10-11 12:00:00Z], [~U[2026-10-11 13:00:00Z], nil])
false
iex> Visualize.Feed.Window.trim([%{t: 1}, %{t: 5}, %{t: 9}], :t, [2, nil])
[%{t: 5}, %{t: 9}]Summary
Functions
Whether a window applies to a window field of the type, :time or :number (spec/08
§11.2): its bounds instants for :time, numbers for :number. A nil window, and one
with no bound, applies to either; a window that mixes kinds, or whose bounds are no
times, applies to neither.
The rows whose field lies in [from, upper): from inclusive and open when nil,
upper exclusive and open when nil. The seam of a combination (spec/08 §11.5).
:lt, :eq or :gt between two times of one kind: numbers by value, and DateTime,
NaiveDateTime and Date each by their own compare/2.
The earlier of two times, a nil ignored.
Whether a value is an instant: a DateTime, a NaiveDateTime or a Date — what a
:time window field holds (spec/08 §10.1, D-154). A number is not one.
The intersection of two windows, either nil for everything. Bounds take the later
from and the earlier to.
The later of two times, a nil ignored.
The rows whose field lies strictly after time, every row for nil. The seam
between what a feed holds and a push (spec/08 §11.4).
A time as a number, for a reduction's x: a number itself, a DateTime its Unix
microseconds, a NaiveDateTime its Gregorian seconds and a Date its Gregorian days.
Anything else is nil, a gap.
Whether a value is one a window can be over: a number, or an instant (instant?/1).
The rows whose field lies within the window (within?/2), in their order; every row
for a nil window. The field is read by either spelling (Visualize.Data.Table.get/2).
Whether a time lies within a window: both bounds inclusive, a nil bound open, a nil
window everything. A nil time lies within no window but nil.
Types
@type t() :: [time() | nil] | nil
@type time() :: number() | DateTime.t() | NaiveDateTime.t() | Date.t()
Functions
Whether a window applies to a window field of the type, :time or :number (spec/08
§11.2): its bounds instants for :time, numbers for :number. A nil window, and one
with no bound, applies to either; a window that mixes kinds, or whose bounds are no
times, applies to neither.
iex> Visualize.Feed.Window.applies?([~U[2026-10-12 00:00:00Z], nil], :time)
true
iex> Visualize.Feed.Window.applies?([~U[2026-10-12 00:00:00Z], nil], :number)
false
iex> Visualize.Feed.Window.applies?([0, 10], :number)
trueThe rows whose field lies in [from, upper): from inclusive and open when nil,
upper exclusive and open when nil. The seam of a combination (spec/08 §11.5).
iex> Visualize.Feed.Window.before([%{t: 1}, %{t: 5}, %{t: 9}], :t, nil, 5)
[%{t: 1}]:lt, :eq or :gt between two times of one kind: numbers by value, and DateTime,
NaiveDateTime and Date each by their own compare/2.
iex> Visualize.Feed.Window.compare(1, 1.0)
:eqThe earlier of two times, a nil ignored.
Whether a value is an instant: a DateTime, a NaiveDateTime or a Date — what a
:time window field holds (spec/08 §10.1, D-154). A number is not one.
iex> Visualize.Feed.Window.instant?(~D[2026-10-12])
true
iex> Visualize.Feed.Window.instant?(12)
falseThe intersection of two windows, either nil for everything. Bounds take the later
from and the earlier to.
iex> Visualize.Feed.Window.intersect([0, 10], [5, nil])
[5, 10]The later of two times, a nil ignored.
iex> Visualize.Feed.Window.latest(nil, 3)
3The rows whose field lies strictly after time, every row for nil. The seam
between what a feed holds and a push (spec/08 §11.4).
iex> Visualize.Feed.Window.newer([%{t: 1}, %{t: 5}, %{t: 9}], :t, 5)
[%{t: 9}]A time as a number, for a reduction's x: a number itself, a DateTime its Unix
microseconds, a NaiveDateTime its Gregorian seconds and a Date its Gregorian days.
Anything else is nil, a gap.
iex> Visualize.Feed.Window.position(~U[1970-01-01 00:00:01Z])
1000000Whether a value is one a window can be over: a number, or an instant (instant?/1).
The rows whose field lies within the window (within?/2), in their order; every row
for a nil window. The field is read by either spelling (Visualize.Data.Table.get/2).
Whether a time lies within a window: both bounds inclusive, a nil bound open, a nil
window everything. A nil time lies within no window but nil.