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//! A crate for generating plural rule operands from numberical input.
//!
//! This crate generates plural operands according to the specifications outlined at [Unicode's website](https://unicode.org/reports/tr35/tr35-numbers.html#Operands).
//!
//! Input is supported for int, float, and &str.
//!
//! # Examples
//!
//! Plural rules example for Polish
//!
//! ```
//! use intl_pluralrules::{PluralRules, PluralRuleType, PluralCategory};
//! use unic_langid::LanguageIdentifier;
//!
//! let langid: LanguageIdentifier = "pl".parse().expect("Parsing failed.");
//!
//! assert!(PluralRules::get_locales(PluralRuleType::CARDINAL).contains(&langid));
//!
//! let pr = PluralRules::create(langid.clone(), PluralRuleType::CARDINAL).unwrap();
//! assert_eq!(pr.select(1), Ok(PluralCategory::ONE));
//! assert_eq!(pr.select("3"), Ok(PluralCategory::FEW));
//! assert_eq!(pr.select(12), Ok(PluralCategory::MANY));
//! assert_eq!(pr.select("5.0"), Ok(PluralCategory::OTHER));
//!
//! assert_eq!(pr.get_locale(), &langid);
//! ```
/// A public AST module for plural rule representations.
pub mod operands;
#[cfg(not(tarpaulin_include))]
mod rules;
use std::convert::TryInto;
use unic_langid::LanguageIdentifier;
use crate::operands::PluralOperands;
use crate::rules::*;
/// A public enum for handling the plural category.
/// Each plural category will vary, depending on the language that is being used and whether that language has that plural category.
#[derive(Debug, Eq, PartialEq)]
pub enum PluralCategory {
ZERO,
ONE,
TWO,
FEW,
MANY,
OTHER,
}
/// A public enum for handling plural type.
#[derive(Copy, Clone, Hash, PartialEq, Eq)]
pub enum PluralRuleType {
/// Ordinal numbers express position or rank in a sequence. [More about oridinal numbers](https://en.wikipedia.org/wiki/Ordinal_number_(linguistics))
ORDINAL,
/// Cardinal numbers are natural numbers. [More about cardinal numbers](https://en.wikipedia.org/wiki/Cardinal_number)
CARDINAL,
}
// pub use rules::PluralRuleType;
/// CLDR_VERSION is the version of CLDR extracted from the file used to generate rules.rs.
pub use crate::rules::CLDR_VERSION;
/// The main structure for selecting plural rules.
///
/// # Examples
///
/// ```
/// use intl_pluralrules::{PluralRules, PluralRuleType, PluralCategory};
/// use unic_langid::LanguageIdentifier;
///
/// let langid: LanguageIdentifier = "naq".parse().expect("Parsing failed.");
/// let pr_naq = PluralRules::create(langid, PluralRuleType::CARDINAL).unwrap();
/// assert_eq!(pr_naq.select(1), Ok(PluralCategory::ONE));
/// assert_eq!(pr_naq.select("2"), Ok(PluralCategory::TWO));
/// assert_eq!(pr_naq.select(5.0), Ok(PluralCategory::OTHER));
/// ```
#[derive(Clone)]
pub struct PluralRules {
locale: LanguageIdentifier,
function: PluralRule,
}
impl PluralRules {
/// Returns an instance of PluralRules.
///
/// # Examples
/// ```
/// use intl_pluralrules::{PluralRules, PluralRuleType, PluralCategory};
/// use unic_langid::LanguageIdentifier;
///
/// let langid: LanguageIdentifier = "naq".parse().expect("Parsing failed.");
/// let pr_naq = PluralRules::create(langid, PluralRuleType::CARDINAL);
/// assert_eq!(pr_naq.is_ok(), !pr_naq.is_err());
///
/// let langid: LanguageIdentifier = "xx".parse().expect("Parsing failed.");
/// let pr_broken = PluralRules::create(langid, PluralRuleType::CARDINAL);
/// assert_eq!(pr_broken.is_err(), !pr_broken.is_ok());
/// ```
pub fn create<L: Into<LanguageIdentifier>>(
langid: L,
prt: PluralRuleType,
) -> Result<Self, &'static str> {
let langid = langid.into();
let returned_rule = match prt {
PluralRuleType::CARDINAL => {
let idx = rules::PRS_CARDINAL.binary_search_by_key(&&langid, |(l, _)| l);
idx.map(|idx| rules::PRS_CARDINAL[idx].1)
}
PluralRuleType::ORDINAL => {
let idx = rules::PRS_ORDINAL.binary_search_by_key(&&langid, |(l, _)| l);
idx.map(|idx| rules::PRS_ORDINAL[idx].1)
}
};
match returned_rule {
Ok(returned_rule) => Ok(Self {
locale: langid,
function: returned_rule,
}),
Err(_) => Err("unknown locale"),
}
}
/// Returns a result of the plural category for the given input.
///
/// If the input is not numeric.
///
/// # Examples
/// ```
/// use intl_pluralrules::{PluralRules, PluralRuleType, PluralCategory};
/// use unic_langid::LanguageIdentifier;
///
/// let langid: LanguageIdentifier = "naq".parse().expect("Parsing failed.");
/// let pr_naq = PluralRules::create(langid, PluralRuleType::CARDINAL).unwrap();
/// assert_eq!(pr_naq.select(1), Ok(PluralCategory::ONE));
/// assert_eq!(pr_naq.select(2), Ok(PluralCategory::TWO));
/// assert_eq!(pr_naq.select(5), Ok(PluralCategory::OTHER));
/// ```
pub fn select<N: TryInto<PluralOperands>>(
&self,
number: N,
) -> Result<PluralCategory, &'static str> {
let ops = number.try_into();
let pr = self.function;
match ops {
Ok(ops) => Ok(pr(&ops)),
Err(_) => Err("Argument can not be parsed to operands."),
}
}
/// Returns a list of the available locales.
///
/// # Examples
/// ```
/// use intl_pluralrules::{PluralRules, PluralRuleType};
///
/// assert_eq!(
/// PluralRules::get_locales(PluralRuleType::CARDINAL).is_empty(),
/// false
/// );
/// ```
pub fn get_locales(prt: PluralRuleType) -> Vec<LanguageIdentifier> {
let prs = match prt {
PluralRuleType::CARDINAL => rules::PRS_CARDINAL,
PluralRuleType::ORDINAL => rules::PRS_ORDINAL,
};
prs.iter().map(|(l, _)| l.clone()).collect()
}
/// Returns the locale name for this PluralRule instance.
///
/// # Examples
/// ```
/// use intl_pluralrules::{PluralRules, PluralRuleType};
/// use unic_langid::LanguageIdentifier;
///
/// let langid: LanguageIdentifier = "naq".parse().expect("Parsing failed.");
/// let pr_naq = PluralRules::create(langid.clone(), PluralRuleType::CARDINAL).unwrap();
/// assert_eq!(pr_naq.get_locale(), &langid);
/// ```
pub fn get_locale(&self) -> &LanguageIdentifier {
&self.locale
}
}
#[cfg(test)]
mod tests {
use super::{PluralCategory, PluralRuleType, PluralRules, CLDR_VERSION};
use unic_langid::LanguageIdentifier;
#[test]
fn cardinals_test() {
let langid: LanguageIdentifier = "naq".parse().expect("Parsing failed.");
let pr_naq = PluralRules::create(langid, PluralRuleType::CARDINAL).unwrap();
assert_eq!(pr_naq.select(1), Ok(PluralCategory::ONE));
assert_eq!(pr_naq.select(2), Ok(PluralCategory::TWO));
assert_eq!(pr_naq.select(5), Ok(PluralCategory::OTHER));
let langid: LanguageIdentifier = "xx".parse().expect("Parsing failed.");
let pr_broken = PluralRules::create(langid, PluralRuleType::CARDINAL);
assert_eq!(pr_broken.is_err(), !pr_broken.is_ok());
}
#[test]
fn ordinals_rules() {
let langid: LanguageIdentifier = "uk".parse().expect("Parsing failed.");
let pr_naq = PluralRules::create(langid, PluralRuleType::ORDINAL).unwrap();
assert_eq!(pr_naq.select(33), Ok(PluralCategory::FEW));
assert_eq!(pr_naq.select(113), Ok(PluralCategory::OTHER));
}
#[test]
fn version_test() {
assert_eq!(CLDR_VERSION, 37);
}
#[test]
fn locale_test() {
assert_eq!(
PluralRules::get_locales(PluralRuleType::CARDINAL).is_empty(),
false
);
}
}