Go rant

[Daniel de Kok]

On 2009-12-21 19:13:48 +0100, Andrei Alexandrescu 
<SeeWebsiteForEmail at erdani.org> said:
> I disagree. We don't want to educate people to write patently 
> inefficient code and in poor programming practice.

I do not mind it, it's ok for explaining a concept clearly. Of course, 
inadequacies should also be discussed. I'd argue that these are also 
the thinking steps normally involved in designing a solution to a 
problem: first try to solve it in the obvious way to understand the 
problem. Then, make a more performant implementation. Of course, 
performant also depends on the context. I have written a lot of C++ 
code that tries to squeeze the last bit of performance out of the 
machine in a single-core world, but it is also difficult to 
parallelize. In a parallel world, the 'slower' solution is sometimes 
better.

> In my mind "elegant" and "at a polynomial blowup in complexity" can't 
> be reconciled anywhere outside a Turing machine introduction where 
> everything is equivalent within a polynomial difference in time and 
> space.

Elegant in the sense of being able to describe a concept briefly. The 
in-place quicksort does not do this.

> I think that's a roundabout way of saying that functional programming 
> is unable to express certain algorithms easily or at all.

...in pure FP. Of course, another problem is that some algorithms are 
inherently imperative. For instance, I find calculating the edit 
distance in a performant manner ugly in functional languages.

-- Daniel