What is unorm?
The 'unorm' npm package provides Unicode normalization forms as specified in Unicode Standard Annex #15. It allows developers to normalize Unicode strings to ensure consistent representation of characters, which is crucial for string comparison, searching, and sorting.
What are unorm's main functionalities?
Normalization to NFC
This feature normalizes a string to the NFC (Normalization Form C) form, which composes characters to their canonical composed form.
const unorm = require('unorm');
const str = '\u1E9B\u0323';
const normalizedStr = unorm.nfc(str);
console.log(normalizedStr);
Normalization to NFD
This feature normalizes a string to the NFD (Normalization Form D) form, which decomposes characters to their canonical decomposed form.
const unorm = require('unorm');
const str = '\u1E9B\u0323';
const normalizedStr = unorm.nfd(str);
console.log(normalizedStr);
Normalization to NFKC
This feature normalizes a string to the NFKC (Normalization Form KC) form, which composes characters to their compatibility composed form.
const unorm = require('unorm');
const str = '\u1E9B\u0323';
const normalizedStr = unorm.nfkc(str);
console.log(normalizedStr);
Normalization to NFKD
This feature normalizes a string to the NFKD (Normalization Form KD) form, which decomposes characters to their compatibility decomposed form.
const unorm = require('unorm');
const str = '\u1E9B\u0323';
const normalizedStr = unorm.nfkd(str);
console.log(normalizedStr);
Other packages similar to unorm
normalize-strings
The 'normalize-strings' package offers utilities for normalizing Unicode strings. It supports the same normalization forms as 'unorm' and includes additional utilities for string comparison and validation.
This is Unicode Normalizer in a Common JS module. I'm not affiliated with Matsuza, the original author of Unicode Normalizer.
Installation
npm install unorm
Polyfill
You can use this module as a polyfill for String.prototype.normalize, for example:
console.log('æøåäüö'.normalize('NFKD'));
The module uses some EcmaScript 5 features. Other browsers should use a compability shim, e.g. es5-shim.
Functions
This module exports four functions: nfc
, nfd
, nfkc
, and nfkd
; one for each Unicode normalization. In the browser the functions are exported in the unorm
global. In CommonJS environments you just require the module. Functions:
unorm.nfd(str)
– Canonical Decompositionunorm.nfc(str)
– Canonical Decomposition, followed by Canonical Compositionunorm.nfkd(str)
– Compatibility Decompositionunorm.nfkc(str)
– Compatibility Decomposition, followed by Canonical Composition
Node.JS example
For a longer example, see examples
directory.
var unorm = require('unorm');
var text =
'The \u212B symbol invented by A. J. \u00C5ngstr\u00F6m ' +
'(1814, L\u00F6gd\u00F6, \u2013 1874) denotes the length ' +
'10\u207B\u00B9\u2070 m.';
var combining = /[\u0300-\u036F]/g;
console.log('Regular: ' + text);
console.log('NFC: ' + unorm.nfc(text));
console.log('NFD: ' + unorm.nfd(text));
console.log('NFKC: ' + unorm.nfkc(text));
console.log('NFKD: * ' + unorm.nfkd(text).replace(combining, ''));
console.log(' * = Combining characters removed from decomposed form.');
Road map
As of October 2013.
Short term:
- Test harness by using the Unicode normalization test suite and examples from the reports
Longer term:
- Look at the unicode data compiler to create up-to-date (Unicode 6.2.0) compatible normalization
- Look at possible optimizations (speed primarely, module size secondarily)
- Adding functions to quick check normalizations:
is_nfc
, is_nfd
, etc.
Contributers
- Oleg Grenrus cleaned up the code base and fixed JSHint errors.
License
This project includes the software package Unicode Normalizer 1.0.0. The
software dual licensed under the MIT and GPL licenses. Here is the MIT license:
Copyright (c) 2008-2013 Matsuza <matsuza@gmail.com>, Bjarke Walling <bwp@bwp.dk>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to
deal in the Software without restriction, including without limitation the
rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
sell copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
IN THE SOFTWARE.