[clean-list] support for OpenGl

[Maks Verver]

Hi

At 12:32 5-7-2002 -0400, you wrote:
>1. can you tell me more about concurrency control?

The nice thing about a side effect free language, is that no concurrency 
control in the source code is needed whatsoever (although hints might be 
useful). The compiler (or the run time environment, for that matter) can 
positively decide which parts of the code are independent  and can thus be 
run concurrently (on seperate processors, for example). In computational 
environments (academic work on a multiprocessor supercomputer, for example) 
or applications executing on a (possible dedicated) multi-programmed 
operating system (like any modern operating system, really) this means more 
effective usage of resources.

I believe that when I first heard about Clean, it was still known as 
Concurrent Clean, due to some concurrency control mechanism. I have never 
read anything specific about this, though, and I believe it is no longer 
available in the current version of Clean. I think others (and especially 
the developers) may tell you more about this.

>2. does a constant-time functional queue implementation exist?

For a bounded queue (ie. a queue with some at run-time determined maximum 
number of items) a simple and (time) efficient implementation using a tuple 
containing an array of items and the number of items would suffice. 
Ofcourse, this would make the queue a unique datastructure, but this is 
usually not a problem. If it is, it can be copied in linear time.

In some situations (if the maximum and average size of a queue differ 
greatly), choosing a fixed bound is not acceptable because of the overhead 
in initialization and memory usage, and some other implementation is 
needed. I must admit that I can't think of a suitable implementation for 
the general case. Maybe someone else can answer this question?

Kind regards,
Maks Verver.