# `Flicker.Facet.Range`
[🔗](https://github.com/team-alembic/flicker/blob/v0.1.0/lib/flicker/facet/range.ex#L1)

The cast value of every range-typed facet ([Spec 018](https://github.com/team-alembic/flicker/blob/main/docs/specs/spec-018-rich-facet-types.md)) —
`created:2026-06-01..2026-06-30`, `price:10..50`, `created:last-30-days`.

## Fields

  * `:from` — the lower endpoint, cast per the facet's `:scalar`. `nil` is
    an **open** lower bound (`..2026-06-30` means "up to and including
    June 30th, from whenever").
  * `:to` — the upper endpoint, same casting. `nil` is an open upper bound.
  * `:preset` — the id of the semantic preset this range came from
    (`:last_30_days`), or `nil` for an explicitly typed range.

## Why `:preset` is carried

A resolved range and the preset that produced it are not the same fact. A
pill rendering `%Range{from: ~D[2026-06-29], to: ~D[2026-07-28]}` can only
say "Jun 29 – Jul 28"; one that also knows `preset: :last_30_days` can say
**"Last 30 days"**, which is what the user actually chose. It is also why
presets serialise back to their token rather than their endpoints
([ADR-011](https://github.com/team-alembic/flicker/blob/main/docs/adrs/adr-011-facet-editors-are-modal-subcontexts.md)):
a saved or shared query stays relative instead of freezing to the day it
was made.

Both endpoints are `nil` only for the `all-time` preset, which is a
deliberate no-op filter rather than an empty one — see `unbounded?/1`.

# `t`

```elixir
@type t() :: %Flicker.Facet.Range{
  from: term() | nil,
  preset: atom() | nil,
  to: term() | nil
}
```

A cast range value.

# `single?`

```elixir
@spec single?(t()) :: boolean()
```

Whether both endpoints are set and equal — a single-day date range, or a
numeric range collapsed to one value.

## Examples

    iex> Flicker.Facet.Range.single?(%Flicker.Facet.Range{
    ...>   from: ~D[2026-07-01],
    ...>   to: ~D[2026-07-01]
    ...> })
    true

    iex> Flicker.Facet.Range.single?(%Flicker.Facet.Range{from: 10, to: 50})
    false

    iex> Flicker.Facet.Range.single?(%Flicker.Facet.Range{from: 10})
    false

# `unbounded?`

```elixir
@spec unbounded?(t()) :: boolean()
```

Whether this range constrains nothing — both endpoints open.

`Flicker.Query.to_filter/2` contributes no clause at all for such a range,
which is what makes `all-time` mean "don't filter by date" rather than
"match nothing".

## Examples

    iex> Flicker.Facet.Range.unbounded?(%Flicker.Facet.Range{})
    true

    iex> Flicker.Facet.Range.unbounded?(%Flicker.Facet.Range{preset: :all_time})
    true

    iex> Flicker.Facet.Range.unbounded?(%Flicker.Facet.Range{from: 10})
    false

---

*Consult [api-reference.md](api-reference.md) for complete listing*