JavaScript double colon (bind operator)

Question

As you know, there is a proposal for a shortcut for .bind() function, so you can write:

::this.handleStuff

and it will work like that in es5:

this.handleStuff.bind(this)

My question is: will it be possible to pass arguments this way?

I mean a way of writing this with the aforementioned shortcut:

this.handleStuff.bind(this, 'stuff')

It's a pretty common pattern in React, so it would be nice to shorten it a little.

Michał Perłakowski · Accepted Answer · 2016-08-19 19:34:24Z

165

No. The bind operator (spec proposal) comes in two flavours:

Method extraction

::obj.method     ≡ obj.method.bind(obj)

"virtual method" calls

obj::function    ≡ function.bind(obj)
obj::function(…) ≡ function.call(obj, …)

Neither of them feature partial application. For what you want, you should use an arrow function:

(...args) => this.handleStuff('stuff', ...args) ≡ this.handleStuff.bind(this, 'stuff')

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answered Jul 4, 2015 at 13:32

Bergi

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1 Comment

(There was some discussion about supporting partial application)