On Sun, Sep 7, 2008 at 10:32 PM, Joseph Wright
<[log in to unmask]> wrote:

> I was rather expecting \c_space_token to save the day, but it didn't.
> Hence my confusion: \space isn't a LaTeX3 name.

Correct. \c_space_token is an implicit space token (because it is
assigned with \let:NN) and a explicit space char is needed.