babel-plugin-implicit-function v0.1.1

babel-plugin-implicit-function

This plugin is made to make JS syntax easier to work with functional programming by creating quoted expressions that may be lazily evaluated and work together with functional libraries, like Ramda. I've overloaded the ~ prefix unary operator for that.

Examples

import { cond } from 'ramda';

const precomputedResult = ~(10 === 20);
const otherwise = ~true;
const matches = cond([
    [precomputedResult, ~'Something is reeeeally wrong!'],
    [otherwise, ~'Nice! Math still works!']
]);

Turn into

import { cond } from 'ramda';

const precomputedResult = () => 10 === 20;
const otherwise = () => true;
const matches = cond([
    [precomputedResult, () => 'Something is reeeeally wrong!'],
    [otherwise, () => 'Nice! Math still works!']
]);

This is a good replacement for always function, because this is really lazy, and the value only gets computed when you need it. Using always can cause problems by premature evaluation:

getUsers()
    .then(always(doSomethingImportantAndReturn());

Note that doSomethingImportantAndReturn needs getUsers to be computed before, but that's not what happen, and this is a source of error and code smell. We could easily fix that with ~ operator. Remember: never use always!

getUsers()
    .then(~doSomethingImportantAndReturn());

Disabling in current scope

If you want to use the original bitwise negation operator, you can disable this plugin in current scope (and it children scopes) using 'no implicit function' directive.

Installation

$ npm install --save-dev babel-plugin-implicit-function

Usage

Via .babelrc (Recommended)

.babelrc

{
  "plugins": ["implicit-function"]
}

Via CLI

$ babel --plugins implicit-function script.js

Via Node API

require('babel-core').transform('code', {
  plugins: ['implicit-function']
});

License

MIT