pocesar / js-diacritic-regex

Creates the inverse of transliterated string to a regex. What? Basically, diacritic insensitiveness

Diacritic regex

Creates the inverse of transliterated string to a regex. What? Basically, a regex that is diacritic insensitive

Why?

Sometimes the user will search for blasé, but your database is dumb and doesn't understand collations and diacritic insensitiveness, but it can compare stuff using regex, so there ya go.

How?

Suppose you have the word résumé but written improperly in the database as resume. The user is clever, and types it correctly into the search box. Gets nothing. How to search for all the weird cases people mistype stuff when comes to accents?

import { toRegex, toString } from 'diacritic-regex';

toRegex()('résumé') // => /r[eEÉéÈèÊêëË]s[úùÚÙüÜuU]m[eEÉéÈèÊêëË]/i;
toRegex({flags: 'mu'})('résumé') // => /r[eEÉéÈèÊêëË]s[úùÚÙüÜuU]m[eEÉéÈèÊêëË]/mu;
toRegex({
  flags: '',
  mappings: {
    'e': 'eéÉ'
  }
})('résumé') // => /r[eéÉ]s[úùÚÙüÜuU]m[eéÉ]/;

toString({
    mappings: {
        '*': ['\\S+'] // literals, won't try to wrap in []'s,
        'u': ['u']
    }
})('résumé*') // => 'r[eEÉéÈèÊêëË]sum[eEÉéÈèÊêëË]\S+'

If you want to change the mappings for all instances:

import { mappings } from 'diacritic-regex'

mappings['*'] = ['[\\S\\s]+']

Caveats

Be aware of RegExp.prototype.exec with g flag being stateful

The i flag is appended to the RegExp flags if you don't pass any flags to toRegex

Compatibility

Work in node and the browser, but needs polyfills for Array.reduce, Array.map and Object.keys depending on how old your target browser is

License

MIT

js-diacritic-regex's Issues

Unexpected token

I'm getting this warning message and can't figure out what causing it

WARNING in ./~/diacritic-regex/index.d.ts
Module parse failed: my_project/node_modules/diacritic-regex/index.d.ts Unexpected token (1:7)
You may need an appropriate loader to handle this file type.
SyntaxError: Unexpected token (1:7)
    at Parser.pp$4.raise (my_project/node_modules/acorn/dist/acorn.js:2221:15)
    at Parser.pp.unexpected (my_project/node_modules/acorn/dist/acorn.js:603:10)
    at Parser.pp.expect (my_project/node_modules/acorn/dist/acorn.js:597:28)
    at Parser.pp$1.parseExportSpecifiers (my_project/node_modules/acorn/dist/acorn.js:1215:10)
    at Parser.pp$1.parseExport (my_project/node_modules/acorn/dist/acorn.js:1186:30)
    at Parser.pp$1.parseStatement (my_project/node_modules/acorn/dist/acorn.js:719:71)
    at Parser.pp$1.parseTopLevel (my_project/node_modules/acorn/dist/acorn.js:638:25)
    at Parser.parse (my_project/node_modules/acorn/dist/acorn.js:516:17)
    at Object.parse (my_project/node_modules/acorn/dist/acorn.js:3098:39)
    at Parser.parse (my_project/node_modules/webpack/lib/Parser.js:902:15)
 @ ./~/diacritic-regex ^\.\/.*$

Returning uppercase and lowercase variations with /i

When regex option "i" is passed, it's not necessary to generate upper and lowercase variations in regex.

Example:
toRegex({ flags: 'i' })('olá') should return /ol[aáàãä]/i;

When flag 'i' is not passed, should return /ol[aAáÁàÀãÃäÄ]/

Issue with special characters (, ), \,

calling toRegex with a string containing open parenthesis (, ) or backslash \, return
Uncaught SyntaxError: Invalid regular expression: //: \ at end of pattern

For example, calling toRegex({ flags: 'i' })("résumé ("); throw

Uncaught SyntaxError: Invalid regular expression: /r[EeÈèÉéÊêËë]s[UuÙùÚúÛûÜü]m[EeÈèÉéÊêËë] (/: Unterminated group