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Subject: Re: [proto] Transform result_of nightmare and preserving terminal identity
From: Agustín K-ballo Bergé (kaballo86_at_[hidden])
Date: 2012-11-01 00:49:16

On 31/10/2012 05:28 p.m., Agustín K-ballo Bergé wrote:
> On 31/10/2012 04:59 p.m., Eric Niebler wrote:
>>> >I will
>>> >continue my research by implementing a custom evaluation context that
>>> >does this optimization 'on the fly', without actually modifying the
>>> >expression.
> >
>> Evaluation contexts are weaker than transforms. If it can't be done with
>> a transform, it can't be done with a context. I can't tell from the code
>> fragment what exactly you're doing with the transforms you've written,
>> or whether they can be improved.
> Quoting from my original mail, what I want is to replace the following
> geometric vector expression:
> p = q + r;
> by
> p[0] = q[0] + r[0],
> p[1] = q[1] + r[1],
> ...,
> p[N] = q[N] + r[N],
> p;
> It **can** be done with a transform and that's what I did. The optimized
> proto expression evaluates ~33% faster than the original proto expression.
> I believe it can also be done with an evaluation context, that evaluates
> an expression N times with a component-wise evaluation context. A
> component-wise evaluation context would be a default context evaluation
> except that vector terminals are evaluated to one of its scalar components.
> Now that my transform finally works as intended, I will clean up the
> code and upload it somewhere for you and anyone interested to see it.

I have uploaded my experiment to .
It only implements what is needed for my research, there are wholes
pretty much everywhere.

Agustín K-ballo Bergé.-

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