An AWS CloudSearch structured query syntax representation of ranges that may be inclusive or exclusive, open or closed, and may be constructed of integers, floats, DateTime.t/0 values, or (in some cases) strings.

A brief note about notation: { and } denote exclusive range bounds; [ and ] denote inclusive range bounds.

Inclusive or Exclusive Ranges

Ranges that are inclusive cover the entire range, including the boundaries of the range. These are typical of Elixir Range.t/0 values. The Elixir range 1..10 is all integers from 1 through 10. CSQuery.Range values may be lower-bound exclusive, upper-bound exclusive, or both-bound exclusive.

• [1,10]: lower- and upper-bound inclusive. Integers 1 through 10.
• {1,10}: lower- and upper-bound exclusive; Integers 2 through 9.
• {1,10]: lower-bound exclusive, upper-bound inclusive. Integers 2 through 10.
• [1,10}: lower-bound inclusive, upper-bound exclusive. Integers 1 through 9.

Open or Closed Ranges

An open range is one that omits either the upper or lower bound. Representationally, an omitted bound must be described as exclusive.

• {,10]: Open range for integers up to 10.
• [10,}: Open range for integers 10 or larger.

Logically, a fully open range ({,}) is possible, but is meaningless in the context of a search, so a CSQuery.OpenRangeError will be thrown.

iex> new({nil, nil})
** (CSQuery.OpenRangeError) CSQuery.Range types may not be open on both upper and lower bounds.

iex> new(%{})
** (CSQuery.OpenRangeError) CSQuery.Range types may not be open on both upper and lower bounds.

Range Types

Elixir range values are restricted to integers. CloudSearch ranges may be:

• Integers:

  iex> new({1, 10}) |> to_value
  "[1,10]"

• Floats:

  iex> new({:math.pi(), :math.pi() * 2}) |> to_value
  "[3.141592653589793,6.283185307179586]"

• Mixed numbers:

  iex> new({1, :math.pi() * 2}) |> to_value
  "[1,6.283185307179586]"

• Timestamps

  iex> start = %DateTime{
  ...>  year: 2018, month: 7, day: 21,
  ...>  hour: 17, minute: 55, second: 0,
  ...>  time_zone: "America/Toronto", zone_abbr: "EST",
  ...>  utc_offset: -14_400, std_offset: 0
  ...> }
  iex> finish = %DateTime{
  ...>  year: 2018, month: 7, day: 21,
  ...>  hour: 19, minute: 55, second: 0,
  ...>  time_zone: "America/Toronto", zone_abbr: "EST",
  ...>  utc_offset: -14_400, std_offset: 0
  ...> }
  iex> new({start, finish}) |> to_value
  "['2018-07-21T17:55:00-04:00','2018-07-21T19:55:00-04:00']"

• Strings

  iex> new({"a", "z"}) |> to_value
  "['a','z']"

integers, floats, timestamps, or strings.

CSQuery.Range construction looks for compatible types (integers and floats may be mixed, but neither timestamps nor strings may be mixed with other types), and a CSQuery.RangeValueTypeError will be thrown if incompatible types are found.

iex> new(%{first: 3, last: "z"})
** (CSQuery.RangeValueTypeError) CSQuery.Range types must be compatible (numbers, dates, and strings may not be mixed).

iex> new(%{first: DateTime.utc_now(), last: "z"})
** (CSQuery.RangeValueTypeError) CSQuery.Range types must be compatible (numbers, dates, and strings may not be mixed).