Morten Høgholm wrote:



> On Mon, 31 Dec 2007 16:44:35 +0100, Andreas Matthias wrote:

> 

> Hi Andreas,

> 

>> I struggled a while to understand how to use \prg_whiledo:nT.

>> I think I figured it out, but it seems to be rather clumsy:

>> 

>> 

>> \RequirePackage{l3prg}

>> \ExplSyntaxOn

>> 

>> \tlp_new:N \a_tlp

>> \int_new:N \a_int

>> \int_zero:N \a_int

>> 

>> \prg_whiledo:nT {

>>   \tlp_set:Nx \a_tlp {

>>     \predicate_p:n {

>>       \int_compare_p:nNn \a_int < 4 &&

>>       \c_true % some complex tests here

>>     }

>>   }

>>   \exp_after:NN \tlp_if_eq:NNT \a_tlp

> 

> This last line should just be

>   \bool_if:NT \a_tlp

> and I can see we left out \bool_set:Nn functions which evaluate

> such  predicate expressions. It would make sense for such a

> function to work  that way, wouldn't it?



Yes, I missed it, too. But maybe one doesn't need it? At least, if

one uses \prg_whiledo:nT in a straight-forward way as in:



> The entire test could be simplified to

> 

> \prg_whiledo:nT {

>   \predicate:nT{

>     \int_compare_p:nNn \a_int < 4 &&

>     \c_true % some complex tests here

>   }

> }{

>   \io_put_term:x{Loop~ \int_use:N \a_int}

>   \int_incr:N \a_int

> }



Oh, yes. That's it: \predicate:nT. That's what I was looking for.

But yesterday I stubbornly sticked to \predicate_p:n again and again.



>> In xtheorem.sty it is used as:

>> 

>>     \prg_whiledo:nT{

>>       \int_compare:nNnT \etex_lastnodetype:D = \c_eleven

>>     }{\tex_unskip:D}

>> 

>> And actually, this was the way it expected it to work? But

>> it doesn't work, does it? I didn't run xtheorem.sty, though.



Well, again I was misleadingly thinking of \int_compare_p:nNn.

But \int_compare:nNnT succeeds, of course.



Thanks!



Ciao

Andreas