47 lines
1.1 KiB
JavaScript
47 lines
1.1 KiB
JavaScript
import {start as startRe, cont as contRe} from './regex.js'
|
|
|
|
/**
|
|
* Checks if the given character code can start an identifier.
|
|
*
|
|
* @param {number} code
|
|
* Character code to check.
|
|
* @returns {boolean}
|
|
* Whether `code` can start an identifier.
|
|
*/
|
|
// To do: support astrals.
|
|
export function start(code) {
|
|
return startRe.test(String.fromCharCode(code))
|
|
}
|
|
|
|
/**
|
|
* Checks if the given character code can continue an identifier.
|
|
*
|
|
* @param {number} code
|
|
* Character code to check.
|
|
* @returns {boolean}
|
|
* Whether `code` can continue an identifier.
|
|
*/
|
|
// To do: support astrals.
|
|
export function cont(code) {
|
|
const character = String.fromCharCode(code)
|
|
return startRe.test(character) || contRe.test(character)
|
|
}
|
|
|
|
/**
|
|
* Checks if the given value is a valid identifier name.
|
|
*
|
|
* @param {string} name
|
|
* Identifier to check.
|
|
* @returns {boolean}
|
|
* Whether `name` can be an identifier.
|
|
*/
|
|
export function name(name) {
|
|
let index = -1
|
|
|
|
while (++index < name.length) {
|
|
if (!(index ? cont : start)(name.charCodeAt(index))) return false
|
|
}
|
|
|
|
// `false` if `name` is empty.
|
|
return index > 0
|
|
}
|