Schwartzian Transform in Python?

[François Pinard]

Lloyd Zusman <ljz at asfast.com> écrit:

> François Pinard <pinard at iro.umontreal.ca> writes:

> > The "technique" called Schwartzian Transform by Perlers is as old as
> > earth (OK, OK!  I agree we should put eternity in some relative context,
> > here :-).  I just wanted to say that I'm surprised that someone could
> > so easily give his name to such an old technique.  I presume that
> > there is some confusion between the syntax and the method?

> Perhaps so ... and in this particular case there could very well also
> be some confusion between the ego and the method ... :)

It reminds me of the superb demonstration of Niklaus Wirth (the "father" of
Pascal) about how to implement integer `i**j' by bit shifting the exponent
while squaring the mantissa, while gargling with Hoare's axioms and loop
invariants, trying to astonish the assembly about those powerful methods
that could come out of "Pascal thinking".  Once again, it was presenting
as new another thing as old as earth, as if he just invented it.

About the same time, I read a fluffy scientific article on disk system
optimisation (walking on the traces of Per Brinch-Hansen's Solo system,
written in Concurrent Pascal, if I remember correctly).  The article
was announcing revolutionary methods and speedup.  But it turned out to
merely push forward the idea of sparing disk revolutions by allocating
files over odd sectors of a given cylinder before using the even sectors.
Something that has been current for _years_ on the CDC mainframes of
the time, and that was just inherent to drum programming (according to
tales old people were telling me at the time).  Even my little Apple ][
and CP\M were doing exactly this while formatting diskettes (yet I surely
do not remember the details! :-)

All the time, and still now, I see oldish ideas being appropriated by later
people, changing the terminology (sometimes by a great deal), adding some
fluff (sometimes a lot of fluff).  But, if you go as far as scratching
the surface a tiny bit, these are rather minor things.  In some way,
I often feel that things do not evolve as fast as some like to think.
We confuse our own learning with the feeling that things just happened.

-- 
François Pinard   http://www.iro.umontreal.ca/~pinard