[texhax] Constructing a very thin space

[Philip Taylor]

Paul Isambert wrote:

> The space is important in the definition so a subsequent space, if
> any is not gobbled. In other words, the space in the definition makes
> sure the macro will have no effect on the tokens to come.

That point I had completely failed to appreciate (until now).
Thank you.

> In an old TUGboat paper, Donald Arseneau, Raymond Chen and Victor 
> Eijkhout introduced a “TeX Hierearchy”, describing levels of
> knowledge characterizing novices, programmers, wizards, etc., in TeX.
> They did not include space tokens as shibboleths, but they could have
> done so: - the novice’s document is riddled with unwanted spaces; -
> the user puts “%” everywhere, avoiding spurious spaces but sometimes 
> running into trouble; - the wizard knows when s/he should ask
> her/himself whether to leave a space or not, and how to answer that
> question; - the guru always knows when to put a space character or
> not, even when spaces have funny catcodes.

"Some are born gurus. Some achieve guruhood. And some, no
matter how long they practise, will never have guruhood thrust
upon them" :-)

** Phil.