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Ruby runtime methods for CLDR plural rules (see camertron/cldr-plurals).


gem install cldr-plurals-runtime-rb


require 'cldr-plurals/ruby_runtime'


The CLDR data set contains plural information for numerous languages in an expression-based format defined by Unicode's TR35. The document describes how to determine the various parts of a number and how to use those parts to determine the plural rule. The parts as they appear in TR35 are:

Symbol Value
n absolute value of the source number (integer and decimals).
i integer digits of n.
v number of visible fraction digits in n, with trailing zeros.
w number of visible fraction digits in n, without trailing zeros.
f visible fractional digits in n, with trailing zeros.
t visible fractional digits in n, without trailing zeros.
c/e compact decimal exponent value

cldr-plurals-runtime-rb is an implementation of these calculations in Ruby. You can use them via the CldrPlurals::RubyRuntime module. Note that all methods take a stringified number as input:

num = '1.04'
CldrPlurals::RubyRuntime.n(num)  # => 1.04
CldrPlurals::RubyRuntime.i(num)  # => 1

This runtime was created primarily for the cldr-plurals project, which can parse and emit Ruby code for a set of plural rules. Here's an example:

require 'cldr-plurals'
require 'cldr-plurals/ruby_runtime'

rules = do |rule_list|
  rule_list.add_rule(:one, 'v = 0 and i % 10 = 1 and i % 100 != 11')
  rule_list.add_rule(:few, 'v = 0 and i % 10 = 2..4 and i % 100 != 12..14')
  rule_list.add_rule(:many, 'v = 0 and i % 10 = 0 or v = 0 and i % 10 = 5..9 or v = 0 and i % 100 = 11..14')

ruby_code = rules.to_code(:ruby)
rule_proc = eval(ruby_code)'3', CldrPlurals::RubyRuntime)  # => :few


No external requirements.

Running Tests

bundle exec rake should do the trick. Alternatively you can run bundle exec rspec, which does the same thing.