CoffeeScript lazy singleton class instance function

Explanation

“@instance:” allows us to attach an object/value to the Foo class instead of Foo’s prototype. Recall that “@” in CoffeeScript refers to JavaScript’s “this”.

After “@instance:” there is a function that is immediately executed. This function returns a function, closed around a variable called instance. Both these functions have their context (their “this”) bound to the Foo object using CoffeeScript’s wonderful “define and bind” operator “=>” as opposed to the normal function definition operator “->”.

When called, the function that “@instance” ends up referring to simply checks to see if the “instance” variable is empty and if so, assigns a new instance of Foo to it. Newing up a Foo is done using the “@” symbol since the function’s “this” refers to the Foo object. It then returns the instance.

Output

The CoffeeScript above compiles down to this:

23,235 thoughts on “CoffeeScript lazy singleton class instance function

  1. I would like to thank you for the efforts you’ve put in penning this site.
    I really hope to see the same high-grade blog
    posts by you later on as well. In truth, your creative writing abilities has motivated me to get my very own blog now ;
    )

  2. The devices available at phone shops can truly enhance your gadget’s performance! I discovered some fantastic gadgets just recently. If you’re interested, check out what phone store has in stock!

  3. customized contracting does superb paintings on my residence

    tradition contracting eavestrough & roofing kitchner roofing
    kitchner roofing tradition contracting eavestrough & roofing
    custom-contracting home improvement tips