On 18/09/2010, at 7:04 AM, Uwe Lueck wrote:



> Will Robertson <[log in to unmask]>, 17.09.2010 07:21:30:

>> 

>> \def\foo{...

>>  \lccode`#1=`\~

> 

> ! Illegal parameter number in definition of \foo.

> 

> And according to my own experience, it must be \lccode`\~=`#1..., 

> cf. doc.sty \@sverb/\do@noligs and below.



Oops, yes, that's of course what I meant :) I was writing off the cuff (and the \def\foo was implied to be inside another macro, say).





On 18/09/2010, at 9:03 AM, Heiko Oberdiek wrote:



>    \providecommand*{\MakeActiveDef}[1]{%

>      \catcode`#1\active

>      \begingroup

>        \lccode`\~`#1%

>        \lowercase{\endgroup \def ~}%

>    }





Ah, this is nice. Better than what I was thinking of as you no longer need a stray active character floating around.



I've added these tentatively to expl3 in the "candidates" module under the names \char_active_set:Npn, \char_active_set_eq:NN, and so on.



Thanks Uwe and Heiko,

-- Will