@formatjs/icu-messageformat-parser

What is @formatjs/icu-messageformat-parser?

The @formatjs/icu-messageformat-parser package is a parser for ICU MessageFormat strings, which are used for internationalization and localization. It allows developers to parse complex message strings into an abstract syntax tree (AST) that can be manipulated or used to format messages based on different locales and pluralization rules.

What are @formatjs/icu-messageformat-parser's main functionalities?

Parsing ICU MessageFormat strings

This feature allows you to parse a simple ICU MessageFormat string and obtain an AST representation of it.

import { parse } from '@formatjs/icu-messageformat-parser';
const ast = parse('My name is {name}');

Handling pluralization and select cases

This feature enables parsing of strings with pluralization and select cases, which are essential for proper internationalization.

import { parse } from '@formatjs/icu-messageformat-parser';
const ast = parse('I have {numCats, plural, one {# cat} other {# cats}}');

Support for nested messages

The parser can handle nested messages within an ICU MessageFormat string, allowing for complex message structures.

import { parse } from '@formatjs/icu-messageformat-parser';
const ast = parse('{gender, select, male {He} female {She} other {They}} will respond shortly.');

Argument types parsing

It can parse argument types such as dates and times, which are commonly used in internationalized messages.

import { parse } from '@formatjs/icu-messageformat-parser';
const ast = parse('The event starts on {startDate, date, long}');

Other packages similar to @formatjs/icu-messageformat-parser

intl-messageformat-parser

This package is a predecessor of @formatjs/icu-messageformat-parser and offers similar functionality for parsing ICU MessageFormat strings. However, @formatjs/icu-messageformat-parser is more up-to-date and maintained by the FormatJS team.

messageformat

Messageformat is a more comprehensive library that not only parses ICU MessageFormat strings but also compiles them into functions that can be used for formatting messages. It provides a higher-level API compared to @formatjs/icu-messageformat-parser.

intl-messageformat

Intl-messageformat is another library from the FormatJS suite that builds on top of the parsing capabilities to provide a full message formatting solution. It uses the parser internally but exposes a higher-level API for formatting operations.

README

MessageFormat Parser

Hand-written ICU MessageFormat parser with compatible output as intl-messageformat-parser but 6 - 10 times as fast.

$ node benchmark
complex_msg AST length 10861
normal_msg AST length 1665
simple_msg AST length 364
string_msg AST length 131

== Baseline ==
complex_msg x 4,884 ops/sec ±0.97% (91 runs sampled)
normal_msg x 40,113 ops/sec ±1.08% (92 runs sampled)
simple_msg x 200,401 ops/sec ±1.12% (91 runs sampled)
string_msg x 241,103 ops/sec ±0.84% (92 runs sampled)

== This package ==
complex_msg x 31,590 ops/sec ±0.80% (88 runs sampled)
normal_msg x 278,703 ops/sec ±0.83% (95 runs sampled)
simple_msg x 2,038,061 ops/sec ±0.90% (96 runs sampled)
string_msg x 2,392,794 ops/sec ±0.67% (96 runs sampled)