[R] Iteration idioms & laziness

[David Duffy]

Duncan Murdoch murdoch at stats.uwo.ca wrote:
> 
> > On 27/11/2009 3:36 PM, Alexander Søndergaard wrote:
> > I'm new to R. Having a functional background, I was wondering what's
> > the idiomatic way to iterate. It seems that for loops are the default
> > given there's no tail-call optimization.
> >
> > I'm curious to know whether there is a way to transform the following
> > toy snippet into something that doesn't eat up gigabytes of memory
> > (like it's for loop counterpart) using laziness:
> >
> > Reduce('+', seq(1,1e6))
> 
> I believe the iterators and foreach packages give ways to iterate
> without creating the whole array, so they might do what you want.

The OP may also be interested in the jit package, which currently 
just covers (see http://www.milbo.users.sonic.net/ra) loops, but 
might eventually extend to TCO.

David Duffy.

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| David Duffy (MBBS PhD)                                         ,-_|\
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