Re: [stack] Why is point-free form so interesting?

This is an approach which I am unfamiliar with, and it does appear to be
very powerful.

Thanks for sharing it!


On 7/10/07, stevan apter <[email protected]> wrote:
>
>   for clarity, nothing beats a 2-d notation with peirce's "lines
> of identity" connecting input and output. for example, consider
> some set of functions f ... each having n arguments and returning
> m results, and suppose that the f's are arranged in some call
> tree. so f calls g with two arguments, which returns three,
> two of which go to h and one to i, each of which returns a
> single result, both of which go to j, which returns two results.
> in a k-like syntax for lambdas, something like
>
> f:{
> [a;b;c]:g[x;y]
> [d;e]:j[h[a;c];i[b]]
> }
>
> now on a sheet of paper, write down g, h, i, and j in any
> orientation with slots for arguments and results:
>
> _ _ _ g _ _
>
> h _ _ i _
>
> _ _ j _ _
>
> now draw lines connecting inputs and outputs (i won't attempt
> that here!)
>
> if any of the functions have "internal structure", replace the
> name of the function with a similar graph. (extra credit:
> how do you diagram recursion?)
>
> death to linear notation -- long live the diagram!
>
>
> ----- Original Message -----
> From: "William Tanksley, Jr" <[email protected]<wtanksleyjr%40gmail.com>
> >
> To: <[email protected] <concatenative%40yahoogroups.com>>
> Sent: Tuesday, July 10, 2007 9:18 AM
> Subject: Re: [stack] Why is point-free form so interesting?
>
> > John Carter <[email protected] <john.carter%40tait.co.nz>> wrote:
> > > Christopher Diggins wrote:
> > > Is there a representation of a program where the mechanism of moving
> > > parameters to values in expressions is...
> > > * Explicit (ie. Can be reasoned about / transparent on inlining)
> > > * Trivial (Adds almost nothing to the code / vanishes in
> > > this representation)?
> >
> > Not in general. If the data transport mechanism is explicit, then the
> > written data transport will vanish only when the data transport needs
> > are simple in the given notation.
> >
> > Stack notation is NOT the simplest possible data transfer notation; it
> > imposes a total ordering on data, when often a partial ordering is
> > sufficient. Adding support for arrays helps a lot; Ripple's support
> > for simultaneous return values is another interesting experiment in
> > this area.
> >
> > So there's plenty of research to be done on this topic.
> >
> > I will add that although in general explicit data transfer can't
> > vanish, it's sometimes (often?) the case that it can be made simpler.
> >
> > > John Carter Phone : (64)(3) 358 6639
> >
> > -Billy
> >
>
> 
>


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