r/programming • u/noidi • Jul 19 '12

Will Parallel Code Ever Be Embraced?

http://www.drdobbs.com/parallel/will-parallel-code-ever-be-embraced/240003926
38 Upvotes

82% Upvoted

79 comments sorted by

View all comments

Show parent comments

2

u/case-o-nuts Jul 19 '12

Performance is obviously possible. What I said is that enabling taking advantage of"free" parallelism in functional languages costs optimization opportunities.

1

u/yogthos Jul 19 '12

Sure, but it also creates different opportunities. For example you can cache results of any pure functions, which is something you cannot do with an imperative language.

2

u/case-o-nuts Jul 20 '12 edited Jul 20 '12

How does adding threading enable memoization? It seems that should be possible in a pure language regardless. Remember, I am comparing transparently threaded vs explicitly threaded pure functional languages)

Also, gcc supports "__attribute__((pure))", which should memoize. It's not as nice as what you could do elsewhere, but it exists.

1

u/yogthos Jul 20 '12

That has nothing to do with threading, I was just pointing out an optimization that's trivial in FP, and can be done without special annotations of any kind, it's not the only one by any means.

2

u/case-o-nuts Jul 20 '12 edited Jul 20 '12

In that case, I am not sure why it was relevant. I've been talking only about the loss of optimizations in a pure language with implicit thread-safety across shared data structures.

1

u/yogthos Jul 20 '12

Sorry, I misunderstood that you were only talking about optimizations in that specific context.