[erlang-questions] Re: Parameterized module idioms

Richard O'Keefe <>
Mon Apr 19 05:20:37 CEST 2010


On Apr 18, 2010, at 9:28 AM, Jayson Vantuyl wrote:

>> For example, [unless you're doing some crazy rewriting tricks] it's
>> obvious which function this is calling:
>>
>>   some_module:echo(E, "hello")
>>
>> This isn't so obvious:
>>
>>   E:echo("hello")
>>
>> Here you have to trace back to the definition of E to find out what
>> module it refers to.
> Actually, that's the point.  There are two good reasons to do this.
>
> 1.  Hide massive amounts of information.

We can already do this with plain old closures.
Instead of
	E:echo("hello")
we can do
	E(echo, "hello")

To a first approximation, any module with parameters can be written
as a function that returns a closure (the standard OO-in-FP trick).
>
> 2.  Polymorphism

Also trivially doable with plain old closures.




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