> On Fri, 14 Jan 2000, John N S Gill wrote:
>
> > I don't think it is true to say that eval doesn't do anything with one
> > arguement. Eg
> >
> > % proc x {args} {
> > puts $args
> > puts [llength $args]
> > }
> > % x {a b c}
> > {a b c}
> > 1
> > % eval x {a b c}
> > a b c
> > 3
>
> Ha! Look again! you gave eval 2 args (x and the list), not one!
Good point, I can't count, but:
% proc x args {
puts $args
puts [llength $args]
}
% eval {x a b c}
a b c
3
% x a b c
a b c
3
% {x a b c}
invalid command name "x a b c"
%
What you get with eval is an extra application of the TCL parser. By
passing the (single) arguement to eval you use the parser to strip
off the quoting {}'s. eval then passes the result on the parser.
This isn't quite a matter of doing nothing.
If eval was doing nothing when called with one argument it ought to
be equivalent to:
proc ee args {
$args
}
But:
% ee {x a b c}
gives:
invalid command name "{x a b c}"
> Also, proc x {args} is a very special case of "args".
err yes.. that was precisely why I was using it. I wanted a command
that wouldn't mind how many arguments it was called with.
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