[texhax] fmt to cls conversion

Philip TAYLOR P.Taylor at rhul.ac.uk
Sat Jun 23 09:49:21 CEST 2012

Heiko Oberdiek wrote:
 > All you have after format generation is the result.
 > The information, how the result was calculated, is lost.

But also irrelevant : a format is a /fait accompli/, and
if the object is to be able to re-create the format from
source, and then to be able to change that source, then
in practice it does not matter whether the source code
with which the reverse engineer ends up is /identical/
to the original source, or merely has the same effect.

 > That means, the right catcodes has to be guessed and the
 > derived definition needs to be verified by comparing (\ifx)
 > with the definition in the format.

Agreed : identity at the \meaning level is not necessarily
suffient, but it is most certainly a good starting point.

 > Also the format could have disabled \meaning to make
 > reverse engineering more difficult.

Of course : the format could have done many devious things.
But is this likely, in the real world ?  All that Messers
Bodducherla and Rao are trying to achieve is to be able
to re-create a source file that will enable them to regenerate
an existing format, and then modify that source file to accomplish
new goals : let us not make their life more difficult by
suggesting artificial difficulties that almost certainly do not
obtain in practice.

Philip Taylor

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