# @messageformat/number-skeleton
Tools for working with [ICU NumberFormat skeletons](https://github.com/unicode-org/icu/blob/master/docs/userguide/format_parse/numbers/skeletons.md) and [patterns](http://unicode.org/reports/tr35/tr35-numbers.html#Number_Format_Patterns).
```js
import {
getNumberFormatter,
getNumberFormatterSource,
NumberFormatError,
parseNumberPattern,
parseNumberSkeleton,
Skeleton, // TS only
Unit // TS only
} from '@messageformat/number-skeleton';
```
The package is released as an ES module only. If using from a CommonJS context, you may need to `import()` it, or use a module loader like [esm](https://www.npmjs.com/package/esm).
Uses [Intl.NumberFormat](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/NumberFormat) internally, including features provided by the [Unified API Proposal](https://github.com/tc39/proposal-unified-intl-numberformat).
## Classes
| Class | Description |
| ----------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [NumberFormatError](https://github.com/messageformat/skeletons/blob/master/docs/messageformat-number-skeleton.numberformaterror.md) | Base class for errors. In addition to a code and a human-friendly message, may also includes the token stem as well as other fields. |
## Functions
| Function | Description |
| --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [getNumberFormatter(locales, skeleton, currency, onError)](https://github.com/messageformat/skeletons/blob/master/docs/messageformat-number-skeleton.getnumberformatter.md) | Returns a number formatter function for the given locales and number skeleton |
| [getNumberFormatterSource(locales, skeleton, currency, onError)](https://github.com/messageformat/skeletons/blob/master/docs/messageformat-number-skeleton.getnumberformattersource.md) | Returns a string of JavaScript source that evaluates to a number formatter function with the same (value: number) => string signature as the function returned by [getNumberFormatter()](https://github.com/messageformat/skeletons/blob/master/docs/messageformat-number-skeleton.getnumberformatter.md). |
| [parseNumberPattern(src, currency, onError)](https://github.com/messageformat/skeletons/blob/master/docs/messageformat-number-skeleton.parsenumberpattern.md) | Parse an [ICU NumberFormatter pattern](http://unicode.org/reports/tr35/tr35-numbers.html#Number_Format_Patterns) string into a [Skeleton](https://github.com/messageformat/skeletons/blob/master/docs/messageformat-number-skeleton.skeleton.md) structure. |
| [parseNumberSkeleton(src, onError)](https://github.com/messageformat/skeletons/blob/master/docs/messageformat-number-skeleton.parsenumberskeleton.md) | Parse an [ICU NumberFormatter skeleton](https://github.com/unicode-org/icu/blob/master/docs/userguide/format_parse/numbers/skeletons.md) string into a [Skeleton](https://github.com/messageformat/skeletons/blob/master/docs/messageformat-number-skeleton.skeleton.md) structure. |
## Interfaces
| Interface | Description |
| ----------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------- |
| [Skeleton](https://github.com/messageformat/skeletons/blob/master/docs/messageformat-number-skeleton.skeleton.md) | An object representation of a parsed string skeleton, with token values grouped by type. |
## Type Aliases
| Type Alias | Description |
| --------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------- |
| [Unit](https://github.com/messageformat/skeletons/blob/master/docs/messageformat-number-skeleton.unit.md) | Measurement units defined by the [Unicode CLDR](https://github.com/unicode-org/cldr/blob/d4d77a2/common/validity/unit.xml) |
---
[Messageformat] is an OpenJS Foundation project, and we follow its [Code of Conduct].
[messageformat]: https://messageformat.github.io/
[code of conduct]: https://github.com/openjs-foundation/cross-project-council/blob/master/CODE_OF_CONDUCT.md
