@babel/plugin-proposal-numeric-separator
This plugin allows Babel to transform Decimal, Binary, Hex and Octal literals containing Numeric Literal Separator to their non-separated form.
Example
Decimal Literals
let budget = 1_000_000_000_000;
console.log(budget === 10 ** 12);
Binary Literals
let nibbles = 0b1010_0001_1000_0101;
console.log(!!(nibbles & (1 << 7)));
Hex Literal
let message = 0xA0_B0_C0;
let a = (message >> 16) & 0xFF;
console.log(a.toString(16), a);
let b = (message >> 8) & 0xFF;
console.log(b.toString(16), b);
let c = message & 0xFF;
console.log(c.toString(16), b);
Octal Literal
hand wave emoji
Octals are great for permissions, but also look better when represented in 0o0000
form. No real benefit with separators here.
Installation
npm install --save-dev @babel/plugin-proposal-numeric-separator
Usage
Via .babelrc
(Recommended)
.babelrc
{
"plugins": ["@babel/plugin-proposal-numeric-separator"]
}
Via CLI
babel --plugins @babel/plugin-proposal-numeric-separator script.js
Via Node API
require("@babel/core").transform("code", {
plugins: ["@babel/plugin-proposal-numeric-separator"]
});
Additional Information
If you need to further compile ES2015 Decimal, Binary, Hex and Octal number representations to their pre-ES2015 numeric literal form, add the "@babel/plugin-transform-literals"
plugin:
@babel/plugin-transform-literals
is already included in @babel/preset-env and @babel/preset-es2015.
Via .babelrc
(Recommended)
.babelrc
{
"presets": ["@babel/preset-env"],
"plugins": ["@babel/plugin-proposal-numeric-separator"]
}
{
"plugins": ["@babel/plugin-proposal-numeric-separator", "@babel/plugin-transform-literals"]
}
References