defmodule Cldr.Time.Interval do
@moduledoc """
Interval formats allow for software to format intervals like "Jan 10-12, 2008" as a
shorter and more natural format than "Jan 10, 2008 - Jan 12, 2008". They are designed
to take a start and end date, time or datetime plus a formatting pattern
and use that information to produce a localized format.
See `Cldr.Interval.to_string/3` and `Cldr.Time.Interval.to_string/3`
"""
alias Cldr.DateTime.Format
import Cldr.Date.Interval,
only: [
format_error: 2,
style_error: 1,
greatest_difference: 2
]
import Cldr.Calendar,
only: [
time: 0
]
# Time styles not defined
# by a grouping but can still
# be used directly
@doc false
@style_map %{
# Can be used with any
# time
time: %{
short: :h,
medium: :hm,
long: :hm
},
# Includes the timezone
zone: %{
short: :hv,
medium: :hmv,
long: :hmv
},
# Includes flex times
# annotation like
# ".. in the evening"
flex: %{
short: :bh,
medium: :bhm,
long: :bhm
}
}
@styles Map.keys(@style_map)
@formats Map.keys(@style_map.time)
@default_format :medium
@default_style :time
def styles do
@style_map
end
@doc false
def to_string(unquote(time()) = from, unquote(time()) = to) do
{locale, backend} = Cldr.locale_and_backend_from(nil, nil)
to_string(from, to, backend, locale: locale)
end
def to_string(nil = from, unquote(time()) = to) do
{locale, backend} = Cldr.locale_and_backend_from(nil, nil)
to_string(from, to, backend, locale: locale)
end
def to_string(unquote(time()) = from, nil = to) do
{locale, backend} = Cldr.locale_and_backend_from(nil, nil)
to_string(from, to, backend, locale: locale)
end
@doc false
def to_string(unquote(time()) = from, unquote(time()) = to, backend) when is_atom(backend) do
{locale, backend} = Cldr.locale_and_backend_from(nil, backend)
to_string(from, to, backend, locale: locale)
end
def to_string(nil = from, unquote(time()) = to, backend) when is_atom(backend) do
{locale, backend} = Cldr.locale_and_backend_from(nil, backend)
to_string(from, to, backend, locale: locale)
end
def to_string(unquote(time()) = from, nil = to, backend) when is_atom(backend) do
{locale, backend} = Cldr.locale_and_backend_from(nil, backend)
to_string(from, to, backend, locale: locale)
end
@doc false
def to_string(unquote(time()) = from, unquote(time()) = to, options) when is_list(options) do
{locale, backend} = Cldr.locale_and_backend_from(options)
to_string(from, to, backend, Keyword.put_new(options, :locale, locale))
end
def to_string(nil = from, unquote(time()) = to, options) when is_list(options) do
{locale, backend} = Cldr.locale_and_backend_from(options)
to_string(from, to, backend, Keyword.put_new(options, :locale, locale))
end
def to_string(unquote(time()) = from, nil = to, options) when is_list(options) do
{locale, backend} = Cldr.locale_and_backend_from(options)
to_string(from, to, backend, Keyword.put_new(options, :locale, locale))
end
@doc """
Returns a string representing the formatted
interval formed by two times.
## Arguments
* `from` is any map that conforms to the
`Calendar.time` type.
* `to` is any map that conforms to the
`Calendar.time` type. `to` must occur
on or after `from`.
* `backend` is any module that includes `use Cldr` and
is therefore `Cldr` backend module
* `options` is a keyword list of options. The default is `[]`.
Either `from` or `to` may also be `nil` in which case the
interval is formatted as an open interval with the non-nil
side formatted as a standalone time.
## Options
* `:format` is one of `:short`, `:medium` or `:long` or a
specific format type or a string representing of an interval
format. The default is `:medium`.
* `:style` supports dfferent formatting styles. The
alternatives are `:time`, `:zone`,
and `:flex`. The default is `:time`.
* `locale` is any valid locale name returned by `Cldr.known_locale_names/0`
or a `Cldr.LanguageTag` struct. The default is `Cldr.get_locale/0`
* `number_system:` a number system into which the formatted date digits should
be transliterated
## Returns
* `{:ok, string}` or
* `{:error, {exception, reason}}`
## Notes
* For more information on interval format string
see `Cldr.Interval`.
* The available predefined formats that can be applied are the
keys of the map returned by `Cldr.DateTime.Format.interval_formats("en", :gregorian)`
where `"en"` can be replaced by any configured locale name and `:gregorian`
is the underlying `CLDR` calendar type.
* In the case where `from` and `to` are equal, a single
time is formatted instead of an interval
## Examples
iex> Cldr.Time.Interval.to_string ~T[10:00:00], ~T[10:03:00], MyApp.Cldr, format: :short
{:ok, "10 – 10"}
iex> Cldr.Time.Interval.to_string ~T[10:00:00], ~T[10:03:00], MyApp.Cldr, format: :medium
{:ok, "10:00 – 10:03 AM"}
iex> Cldr.Time.Interval.to_string ~T[10:00:00], ~T[10:03:00], MyApp.Cldr, format: :long
{:ok, "10:00 – 10:03 AM"}
iex> Cldr.Time.Interval.to_string ~T[10:00:00], ~T[10:03:00], MyApp.Cldr,
...> format: :long, style: :flex
{:ok, "10:00 – 10:03 in the morning"}
iex> Cldr.Time.Interval.to_string ~U[2020-01-01 00:00:00.0Z], ~U[2020-01-01 10:00:00.0Z],
...> MyApp.Cldr, format: :long, style: :flex
{:ok, "12:00 – 10:00 in the morning"}
iex> Cldr.Time.Interval.to_string ~U[2020-01-01 00:00:00.0Z], nil, MyApp.Cldr,
...> format: :long, style: :flex
{:ok, "12:00:00 AM UTC –"}
iex> Cldr.Time.Interval.to_string ~U[2020-01-01 00:00:00.0Z], ~U[2020-01-01 10:00:00.0Z],
...> MyApp.Cldr, format: :long, style: :zone
{:ok, "12:00 – 10:00 AM Etc/UTC"}
iex> Cldr.Time.Interval.to_string ~T[10:00:00], ~T[10:03:00], MyApp.Cldr,
...> format: :long, style: :flex, locale: "th"
{:ok, "10:00 – 10:03 ในตอนเช้า"}
"""
@spec to_string(Calendar.time() | nil, Calendar.time() | nil, Cldr.backend(), Keyword.t()) ::
{:ok, String.t()} | {:error, {module, String.t()}}
def to_string(from, to, backend, options \\ [])
def to_string(%{calendar: calendar} = from, %{calendar: calendar} = to, backend, options)
when calendar == Calendar.ISO do
from = %{from | calendar: Cldr.Calendar.Gregorian}
to = %{to | calendar: Cldr.Calendar.Gregorian}
to_string(from, to, backend, options)
end
def to_string(unquote(time()) = from, unquote(time()) = to, backend, options) do
{locale, backend} = Cldr.locale_and_backend_from(options[:locale], backend)
formatter = Module.concat(backend, DateTime.Formatter)
format = Keyword.get(options, :format, @default_format)
locale_number_system = Cldr.Number.System.number_system_from_locale(locale, backend)
number_system = Keyword.get(options, :number_system, locale_number_system)
options =
options
|> Keyword.put(:locale, locale)
|> Keyword.put(:nunber_system, number_system)
with {:ok, _} <- from_less_than_or_equal_to(from, to),
{:ok, backend} <- Cldr.validate_backend(backend),
{:ok, locale} <- Cldr.validate_locale(locale, backend),
{:ok, _} <- Cldr.Number.validate_number_system(locale, number_system, backend),
{:ok, calendar} <- Cldr.Calendar.validate_calendar(from.calendar),
{:ok, formats} <- Format.interval_formats(locale, calendar.cldr_calendar_type, backend),
{:ok, [left, right]} <- resolve_format(from, to, formats, options),
{:ok, left_format} <- formatter.format(from, left, locale, options),
{:ok, right_format} <- formatter.format(to, right, locale, options) do
{:ok, left_format <> right_format}
else
{:error, :no_practical_difference} ->
options = Cldr.DateTime.Interval.adjust_options(options, locale, format)
Cldr.Time.to_string(from, backend, options)
other ->
other
end
end
# Open ended intervals use the `date_time_interval_fallback/0` format
def to_string(nil, unquote(time()) = to, backend, options) do
{locale, backend} = Cldr.locale_and_backend_from(options[:locale], backend)
with {:ok, formatted} <- Cldr.Time.to_string(to, backend, options) do
pattern = Module.concat(backend, DateTime.Format).date_time_interval_fallback(locale)
result =
["", formatted]
|> Cldr.Substitution.substitute(pattern)
|> Enum.join()
|> String.trim_leading()
{:ok, result}
end
end
def to_string(unquote(time()) = from, nil, backend, options) do
{locale, backend} = Cldr.locale_and_backend_from(options[:locale], backend)
with {:ok, formatted} <- Cldr.Time.to_string(from, backend, options) do
pattern = Module.concat(backend, DateTime.Format).date_time_interval_fallback(locale)
result =
[formatted, ""]
|> Cldr.Substitution.substitute(pattern)
|> Enum.join()
|> String.trim_trailing()
{:ok, result}
end
end
@doc false
def to_string!(unquote(time()) = from, unquote(time()) = to) do
{locale, backend} = Cldr.locale_and_backend_from(nil, nil)
to_string!(from, to, backend, locale: locale)
end
@doc """
Returns a string representing the formatted
interval formed by two times.
## Arguments
* `from` is any map that conforms to the
`Calendar.time` type.
* `to` is any map that conforms to the
`Calendar.time` type. `to` must occur
on or after `from`.
* `backend` is any module that includes `use Cldr` and
is therefore `Cldr` backend module
* `options` is a keyword list of options. The default is `[]`.
## Options
* `:format` is one of `:short`, `:medium` or `:long` or a
specific format type or a string representing of an interval
format. The default is `:medium`.
* `:style` supports dfferent formatting styles. The
alternatives are `:time`, `:zone`,
and `:flex`. The default is `:time`.
* `locale` is any valid locale name returned by `Cldr.known_locale_names/0`
or a `Cldr.LanguageTag` struct. The default is `Cldr.get_locale/0`
* `number_system:` a number system into which the formatted date digits should
be transliterated
## Returns
* `string` or
* raises an exception
## Notes
* For more information on interval format string
see `Cldr.Interval`.
* The available predefined formats that can be applied are the
keys of the map returned by `Cldr.DateTime.Format.interval_formats("en", :gregorian)`
where `"en"` can be replaced by any configured locale name and `:gregorian`
is the underlying `CLDR` calendar type.
* In the case where `from` and `to` are equal, a single
time is formatted instead of an interval
## Examples
iex> Cldr.Time.Interval.to_string! ~T[10:00:00], ~T[10:03:00], MyApp.Cldr, format: :short
"10 – 10"
iex> Cldr.Time.Interval.to_string! ~T[10:00:00], ~T[10:03:00], MyApp.Cldr, format: :medium
"10:00 – 10:03 AM"
iex> Cldr.Time.Interval.to_string! ~T[10:00:00], ~T[10:03:00], MyApp.Cldr, format: :long
"10:00 – 10:03 AM"
iex> Cldr.Time.Interval.to_string! ~T[10:00:00], ~T[10:03:00], MyApp.Cldr,
...> format: :long, style: :flex
"10:00 – 10:03 in the morning"
iex> Cldr.Time.Interval.to_string! ~U[2020-01-01 00:00:00.0Z], ~U[2020-01-01 10:00:00.0Z],
...> MyApp.Cldr, format: :long, style: :flex
"12:00 – 10:00 in the morning"
iex> Cldr.Time.Interval.to_string! ~U[2020-01-01 00:00:00.0Z], ~U[2020-01-01 10:00:00.0Z],
...> MyApp.Cldr, format: :long, style: :zone
"12:00 – 10:00 AM Etc/UTC"
iex> Cldr.Time.Interval.to_string! ~T[10:00:00], ~T[10:03:00], MyApp.Cldr,
...> format: :long, style: :flex, locale: "th"
"10:00 – 10:03 ในตอนเช้า"
"""
def to_string!(from, to, backend, options \\ []) do
case to_string(from, to, backend, options) do
{:ok, string} -> string
{:error, {exception, reason}} -> raise exception, reason
end
end
defp from_less_than_or_equal_to(from, to) do
case Time.compare(from, to) do
comp when comp in [:eq, :lt] -> {:ok, comp}
_other -> {:error, Cldr.Date.Interval.datetime_order_error(from, to)}
end
end
defp resolve_format(from, to, formats, options) do
format = Keyword.get(options, :format, @default_format)
style = Keyword.get(options, :style, @default_style)
with {:ok, style} <- validate_style(style),
{:ok, format} <- validate_format(formats, style, format),
{:ok, greatest_difference} <- greatest_difference(from, to) do
greatest_difference_format(from, to, format, greatest_difference)
end
end
defp greatest_difference_format(_from, _to, format, _) when is_binary(format) do
{:ok, format}
end
defp greatest_difference_format(%{hour: from}, %{hour: to}, format, :H)
when from < 12 and to >= 12 do
case Map.get(format, :b) || Map.get(format, :a) || Map.get(format, :h) do
nil -> {:error, format_error(format, format)}
success -> {:ok, success}
end
end
defp greatest_difference_format(_from, _to, format, :H) do
case Map.fetch(format, :h) do
:error -> {:error, format_error(format, format)}
success -> success
end
end
defp greatest_difference_format(from, to, format, :m = difference) do
case Map.fetch(format, difference) do
:error -> greatest_difference_format(from, to, format, :H)
success -> success
end
end
defp greatest_difference_format(_from, _to, _format, _difference) do
{:error, :no_practical_difference}
end
defp validate_style(style) when style in @styles, do: {:ok, style}
defp validate_style(style), do: {:error, style_error(style)}
# Using standard format terms like :short, :medium, :long
defp validate_format(formats, style, format) when format in @formats do
format_key =
styles()
|> Map.fetch!(style)
|> Map.fetch!(format)
Map.fetch(formats, format_key)
end
# Direct specification of a format
defp validate_format(formats, _style, format_key) when is_atom(format_key) do
IO.inspect(format_key, label: "format key 2")
case Map.fetch(formats, format_key) do
:error -> {:error, format_error(formats, format_key)}
success -> success
end
end
# Direct specification of a format as a string
defp validate_format(_formats, _style, format) when is_binary(format) do
Cldr.DateTime.Format.split_interval(format)
end
end