Re: M-x mystery

[Silvio Levy]

Hi,

Sorry to bother you all, but the info in 
http://www.gnu.org/software/emacs/manual/html_node/elisp/Functions-for-Key-Lookup.html
doesn't seem to correspond to my experience.  I wonder if it
corresponds to yours.

First, let me tell you what does work as described. My ALT key does
seem to be interpreted by Emacs as Meta, in principle. The page above says

        M-<F1>, a function key, is not converted into <ESC> <F1>. 

and indeed, if I type ALT-F5 the response is "<M-f5> undefined", as
expected. (I'm using F5 because my F1 is intercepted by the window
manager - can't figure out how.)

And, ALT-x is interpreted as ESC x, also as described above. 

The problem is the variable meta-prefix-char, which is supposed to
alter that relationship.

If I load a file containing only the command (setq meta-prefix-char [f5])
and check the value of the variable, the answer is [f5].  

******** Yet, after that, ALT-x is still interpreted as ESC x. ********  

You might say that [f5] is not a valid prefix key. But [f2] is (it's
bound to 2C-mode-map in two-column.el). After I set meta-prefix-char
to [f2], typing ALT-x is still interpreted as ESC x, not [f2] x.

In fact, I can't even duplicate the example near the bottom of the
"Functions for Key Lookup" page (link above). Namely, setting
meta-prefix-char to 24 **should** make M-x behave like C-x, according
to that page. But that does not happen; even with meta-prefix-char=24,
ALT-x is interpreted as ESC x.

What have I misunderstood?

This is all in emacs 23.1.50.1 called with -q.

Silvio