babel-plugin-implicit-function
v0.1.1
Published
Babel plugin to allow lazy expressions by implicit arrow functions via ~ operator
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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