96 lines
3.4 KiB
Markdown
96 lines
3.4 KiB
Markdown
# messageformat-parser <a href="http://travis-ci.org/messageformat/parser"><img align="right" alt="Build Status" src="https://secure.travis-ci.org/messageformat/parser.png"></a>
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A [PEG.js] parser for [ICU MessageFormat] strings – part of [messageformat.js].
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Outputs an AST defined by [parser.pegjs].
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The generated parser function takes two parameters, first the string to be
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parsed, and a second optional parameter `options`, an object with the following
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possible keys:
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- `cardinal` and `ordinal` – Arrays of valid plural categories for the current
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locale, used to validate plural and selectordinal keys. If these are missing
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or set to false, the full set of valid [Unicode CLDR] keys is used: `'zero',
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'one', 'two', 'few', 'many', 'other'`. To disable this check, pass in an empty
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array.
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- `strictFunctionParams` – By default, function parameters are split on commas
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and trimmed, so the parameters in `{x,fn, a, b }` are parsed as
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`['a','b']`. Setting `strictFunctionParams` to true will make the parser
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follow the ICU MessageFormat spec more closely, and result in a params array
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with a single element: `[' a, b ']`.
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[ICU MessageFormat]: https://messageformat.github.io/guide/
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[messageformat.js]: https://messageformat.github.io/
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[parser.pegjs]: ./parser.pegjs
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[PEG.js]: http://pegjs.org/
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[Unicode CLDR]: http://cldr.unicode.org/index/cldr-spec/plural-rules
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#### Installation
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```sh
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npm install messageformat-parser
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```
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#### Usage
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```js
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> var parse = require('messageformat-parser').parse;
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> parse('So {wow}.')
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[ 'So ', { type: 'argument', arg: 'wow' }, '.' ]
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> parse('Such { thing }. { count, selectordinal, one {First} two {Second}' +
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' few {Third} other {#th} } word.')
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[ 'Such ',
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{ type: 'argument', arg: 'thing' },
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'. ',
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{ type: 'selectordinal',
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arg: 'count',
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offset: 0,
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cases:
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[ { key: 'one', tokens: [ 'First' ] },
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{ key: 'two', tokens: [ 'Second' ] },
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{ key: 'few', tokens: [ 'Third' ] },
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{ key: 'other', tokens: [ { type: 'octothorpe' }, 'th' ] } ] },
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' word.' ]
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> parse('Many{type,select,plural{ numbers}selectordinal{ counting}' +
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'select{ choices}other{ some {type}}}.')
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[ 'Many',
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{ type: 'select',
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arg: 'type',
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cases:
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[ { key: 'plural', tokens: [ ' numbers' ] },
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{ key: 'selectordinal', tokens: [ ' counting' ] },
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{ key: 'select', tokens: [ ' choices' ] },
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{ key: 'other', tokens: [ ' some',
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{ type: 'argument', arg: 'type' } ] } ] },
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'.' ]
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> parse('{Such compliance')
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// SyntaxError: Expected ",", "}" or [ \t\n\r] but "c" found.
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> var msg = '{words, plural, zero{No words} one{One word} other{# words}}';
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> var englishKeys = { cardinal: [ 'one', 'other' ],
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ordinal: [ 'one', 'two', 'few', 'other' ] };
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> parse(msg)
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[ { type: 'plural',
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arg: 'words',
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offset: 0,
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cases:
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[ { key: 'zero', tokens: [ 'No words' ] },
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{ key: 'one', tokens: [ 'One word' ] },
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{ key: 'other', tokens: [ { type: 'octothorpe' }, ' words' ] } ] } ]
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> parse(msg, englishKeys)
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// Error: Invalid key `zero` for argument `words`. Valid plural keys for this
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// locale are `one`, `other`, and explicit keys like `=0`.
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```
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#### Contributor License Agreement
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See the [messageformat.js README][CLA] for details.
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[CLA]: https://github.com/messageformat/messageformat.js#contributor-license-agreement
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