estree-util-is-identifier-name

estree utility to check if something can be an identifier.

Contents

• What is this?
• When should I use this?
• Install
• Use
• API
  • cont(code[, options])
  • name(name[, options])
  • start(code)
  • Options
• Types
• Compatibility
• Related
• Contribute
• License

What is this?

This package is a utility that can be used to check if something can be an identifier name. For example, a, _, and a1 are fine, but 1 and - are not.

When should I use this?

You can use this utility when generating IDs from strings or parsing IDs.

Install

This package is ESM only. In Node.js (version 14.14+ and 16.0+), install with npm:

npm install estree-util-is-identifier-name

In Deno with esm.sh:

import * as isIdentifierName from 'https://esm.sh/estree-util-is-identifier-name@2'

In browsers with esm.sh:

<script type="module">
  import * as isIdentifierName from 'https://esm.sh/estree-util-is-identifier-name@2?bundle'
</script>

Use

import {cont, name, start} from 'estree-util-is-identifier-name'

name('$something69') // => true
name('69') // => false
name('var') // => true (this does not handle keywords)

start(48) // => false (code point for `'0'`)
cont(48) // => true (code point for `'0'`)

API

This package exports the identifiers cont, name, and start. There is no default export.

cont(code[, options])

Checks if the given code point can continue an identifier.

Parameters

• code (number) — code point to check
• options (Options, optional) — configuration

Returns

Whether code can continue an identifier (boolean).

name(name[, options])

Checks if the given value is a valid identifier name.

Parameters

• name (string) — identifier to check
• options (Options, optional) — configuration

Returns

Whether name can be an identifier (boolean).

start(code)

Checks if the given code point can start an identifier.

Parameters

• code (number) — code point to check

Returns

Whether code can start an identifier (boolean).

Options

Configuration (TypeScript type).

Fields

• jsx (boolean, default: false) — support JSX identifiers.

Types

This package is fully typed with TypeScript. It exports the additional type Options.

Compatibility

Projects maintained by the unified collective are compatible with all maintained versions of Node.js. As of now, that is Node.js 14.14+ and 16.0+. Our projects sometimes work with older versions, but this is not guaranteed.

Related

• goto-bus-stop/estree-is-identifier — check if an AST node is an identifier

Contribute

See contributing.md in syntax-tree/.github for ways to get started. See support.md for ways to get help.

This project has a code of conduct. By interacting with this repository, organization, or community you agree to abide by its terms.

License

MIT © Titus Wormer