i18n: Add i18next plural resolver class

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Samantaz Fox 2021-11-18 17:44:08 +01:00
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@ -80,4 +80,133 @@ module I18next::Plurals
"sk" => PluralForms::Special_Czech_Slovak,
"sl" => PluralForms::Special_Slovenian,
}
# The array indices matches the PluralForms enum above
private NUMBERS = [
[1, 2], # 1
[1, 2], # 2
[1], # 3
[1, 2, 5], # 4
[0, 1, 2, 3, 11, 100], # 5
[1, 2, 5], # 6
[1, 2, 5], # 7
[1, 2, 3, 8], # 8
[1, 2], # 9 (not used)
[1, 2, 3, 7, 11], # 10
[1, 2, 3, 20], # 11
[1, 2], # 12
[0, 1], # 13
[1, 2, 3, 4], # 14
[1, 2, 10], # 15
[1, 2, 0], # 16
[1, 2], # 17
[0, 1, 2], # 18
[1, 2, 11, 20], # 19
[1, 2, 20], # 20
[5, 1, 2, 3], # 21
[1, 2, 20, 21], # 22
]
# "or" ()
private NUMBERS_OR = [2, 1]
# -----------------------------------
# I18next plural resolver class
# -----------------------------------
class Resolver
@@forms : Hash(String, PluralForms) = init_rules()
@@version : UInt8 = 3
# Options
property simplify_plural_suffix : Bool = true
# Suffixes
SUFFIXES_V1 = {
"",
"_plural_1",
"_plural_2",
"_plural_3",
"_plural_11",
"_plural_100",
}
SUFFIXES_V2 = {"_0", "_1", "_2", "_3", "_11", "_100"}
SUFFIXES_V3 = {"_0", "_1", "_2", "_3", "_4", "_5"}
def initialize(version : UInt8 = 3)
# Sanity checks
# V4 isn't supported, as it requires a full CLDR database.
if version > 4 || version == 0
raise "Invalid i18next version: v#{version}."
elsif version == 4
# Logger.error("Unsupported i18next version: v4. Falling back to v3")
@@version = 3
else
@@version = version
end
end
def self.init_rules
# Look into sets
PLURAL_SETS.each do |form, langs|
langs.each { |lang| @@forms[lang] = form }
end
# Add plurals from the "singles" set
@@forms.merge!(PLURAL_SINGLES)
end
def get_plural_form(locale : String) : PluralForms
# Extract the ISO 639-1 or 639-2 code from an RFC 5646
# language code, except for pt-BR which needs to be kept as-is.
if locale.starts_with?("pt-BR")
locale = "pt-BR"
else
locale = locale.split('-')[0]
end
return @@forms[locale] if @@forms[locale]?
# If nothing was found, then use the most common form, i.e
# one singular and one plural, as in english. Not perfect,
# but better than yielding an exception at the user.
return PluralForms::Single_not_one
end
def get_suffix(locale : String, count : Int) : String
# Checked count must be absolute. In i18next, `rule.noAbs` is used to
# determine if comparison should be done on a signed or unsigned integer,
# but this variable is never set, resulting in the comparison always
# being done on absolute numbers.
return get_suffix_retrocompat(locale, count.abs)
end
def get_suffix_retrocompat(locale : String, count : Int) : String
# Get plural form
plural_form = get_plural_form(locale)
rule_numbers = (locale == "or") ? NUMBERS_OR : NUMBERS[plural_form.to_i]
# Languages with no plural have no suffix
return "" if plural_form.none?
# Get the index and suffix for this number
# idx = Todo
suffix = rule_numbers[idx]
# Simple plurals are handled differently in all versions (but v4)
if @simplify_plural_suffix && rule_numbers.size == 2 && rule_numbers[0] == 1
return "_plural" if (suffix == 2)
return "" if (suffix == 1)
end
# More complex plurals
# TODO: support `options.prepend` for v2 and v3
# this.options.prepend && suffix.toString() ? this.options.prepend + suffix.toString() : suffix.toString()
case @version
when 1 then return SUFFIXES_V1[idx]
when 2 then return SUFFIXES_V2[idx]
else return SUFFIXES_V3[idx]
end
end
end
end