[Haskell-cafe] Haskell maximum stack depth

[Don Stewart]

ndmitchell:
> Hi
> 
> > implementations. Certainly my experience of library tuning tells
> > me that (with ghc at least), designing your code and data structures
> > to keep heap allocation down to an absolute minimum is very important.
> 
> Yes. Keeping allocation low is very important, be it heap or stack.
> Heap allocation is not free, its just not any more expensive than the
> stack.
> 
> > A lot also depends on compiler (and associated rts), such as whether
> > or not it translates to CPS, thereby in effect building a "stack" (in
> > all but name) on the heap.
> 
> If you burn a lot of heap, for not much gain, that's still a bug,
> albeit one which large limits might be able to paper over for a short
> amount of time. Is the GHC stack not stored on the heap? I thought it
> was. I know the Hugs stack is stored on the stack, and the Yhc one
> isn't.
> 
> > Surely the alleged buginess of programs should not be dependent
> > on choice of compiler/rst?
> 
> Hmm, debatable. Things like the garbage collection inside tuples can
> change the space behaviour and implementability of some things, and
> are supported by GHC but not Hugs.
> 
> > As nobody has provided any sensible justification for the assertion
> > that using lots of stack (vs. heap) inherently is bad
> 
> My claim is that "any program which needs to adjust the stack size has
> a laziness leak" - since I've made a universally quantified claim, a
> couple of real examples should blow it out of the water.

I think that's a reasonable rule of thumb

-- Don