Re: PIL 3rd electronic version

[Finn Wilcox <finnw@...>]

On 15/05/2013 10:28, steve donovan wrote:
> On Wed, May 15, 2013 at 11:07 AM, Finn Wilcox <finnw@finnw.me.uk
> <mailto:finnw@finnw.me.uk>> wrote:
> 
>     -- defines a factorial function
>     function fact (n)
> 
> 
> Excellent command of written Martian displayed here, but what's the trick?
> 
It's just a substitution cipher, i.e. each character is globally
replaced by another.  I don't have the .pdf, but I am guessing they
generate a random permutation of the codepoints used in the document and
embed a font whose glyphs have the same permutation applied.

And it is easy to guess which is which if you are familiar with the
language.  In this case I started with ❡♥❞, which I guessed meant "end"
as it appears twice on a line by itself.  That was enough to recognize
the remaining Lua keywords, followed by the words in the comment and
finally the punctuation.

But the point I was trying to make was that it is pretty much useless,
other than causing inconvenience (and for the target audience of a
programming book, that inconvenience is quite small.)

Finn