[luatex] Hash tokens meaning

Sensei senseiwa at gmail.com
Wed May 29 12:02:32 CEST 2013

On 5/29/13 12:32am, Reinhard Kotucha wrote:

> I fear that you have to read the TeXbook first.  [...] You can
> investigate LaTeX later. [...] In short: The TeXbook is unavoidable.

As I said multiple times: I've downloaded the TeX book, and I am reading it.

> Arthur already explained that you can't compare TeX with C.  C is a
> low-level language and if you disassemble a program, you can certainly
> see how it works.  However, TeX is extremely complex and you don't
> achieve anything without having read the TeXbook before.

Ok, I get it. I said i *THOUGHT* I could relate it to C, and I also said 
that I was obviously wrong.

>   > (it's part of my job), especially when you assume that you don't
>   > have the source code.
> I hope that what you do is legal and you don't end up in prison one
> day.  :)

It is legal. You just don't see many do reverse engineering. I'm not 15 
anymore to waste time on "cracks".

> However, the TeX source code is available and there shouldn't be a
> need to reverse engineer things.  It's shipped with TeX Live.
> I just created a PDF file for you and put it on my server:
>    http://ms25.ath.cx/tex/tex.pdf
> It describes Knuth's TeX, thus no PDF or Lua related code inside.

Thanks, I have another source to read!

> BTW, I understand that you want to find out how TeX works.  This is
> understandable.  However, I'm convinced that the hash table is by far
> the worst starting point.  I can't imagine a worse one.  The hash
> table is meaningless unless you know where the entries come from and
> what they are good for.

Disclaimer: I am trying to say why I was proceeding that way.

It is quite common to make a dummy program to see how a compiler encodes 
things, how symbols are translated (their names), how the code is 
produced (symbol's contents). I made the same: a dummy latex, and dumped 
the symbols.

> IMO the best approach to make TeX's internals visible is provided by
> Patrick Gundlach.  His tool examines TeX's internals and uses Graphviz
> in order to display them graphically.
> I'm absolutely convinced that everything you're doing at this low
> level is absolutely useless and you waste your time unless you've read
> the TeXbook before.

You've made your point clear.

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