List Formatting

Cldr interprets the CLDR rules for list formatting is a locale-specific way. The list is recursed over and the list elements are passed to Kernel.to_string/1 therefore the list elements can be anything that can be understood by Kernel.to_string/1.

Cldr includes list formatting, see Cldr.List and Cldr.List.to_string/2.

Public API

The primary api for list formatting is Cldr.List.to_string/2. It provides the ability to format lists in a standard way for configured locales. For example:

iex> Cldr.List.to_string(["a", "b", "c"], locale: "en")
"a, b, and c"

iex> Cldr.List.to_string(["a", "b", "c"], locale: "en", format: :unit_narrow)
"a b c"

iex> Cldr.List.to_string(["a", "b", "c"], locale: "fr")
"a, b et c"

iex> Cldr.List.to_string([1,2,3,4,5,6])
"1, 2, 3, 4, 5, and 6"

iex> Cldr.List.to_string(["a"])
"a"

iex> Cldr.List.to_string([1,2])
"1 and 2"

Cldr.List.to_string/2 takes a Keyword list of options where the valid options are:

List Formats

List formats are referred to by a pattern style the standardises the way to refernce different formats in a locale. See Cldr.List.list_pattern_styles_for/1. For example:

iex> Cldr.List.list__pattern_styles_for "en"
[:standard, :standard_short, :unit, :unit_narrow, :unit_short]

iex> Cldr.List.list_pattern_styles_for "ru"
[:standard, :standard_short, :unit, :unit_narrow, :unit_short]

iex> Cldr.List.list_pattern_styles_for "th"
[:standard, :standard_short, :unit, :unit_narrow, :unit_short]

Formatting styles

The five list common formatting styles for a locale are:

  • :standard

  • :standard_short

  • :unit

  • :unit_narrow

  • :unit_short

This list is not fixed or definitive, other styles may be present for a locale.

The definitions of these styles can be explored through Cldr.List.list_patterns_for "locale". For example:

iex> Cldr.List.list_patterns_for "fr"
%{standard: %{"2": "{0} et {1}", end: "{0} et {1}", middle: "{0}, {1}",
    start: "{0}, {1}"},
  standard_short: %{"2": "{0} et {1}", end: "{0} et {1}", middle: "{0}, {1}",
    start: "{0}, {1}"},
  unit: %{"2": "{0} et {1}", end: "{0} et {1}", middle: "{0}, {1}",
    start: "{0}, {1}"},
  unit_narrow: %{"2": "{0} {1}", end: "{0} {1}", middle: "{0} {1}",
    start: "{0} {1}"},
  unit_short: %{"2": "{0} et {1}", end: "{0} et {1}", middle: "{0}, {1}",
    start: "{0}, {1}"}}