This is quite counterintuitive... It also happens if I define a string
variable, use concatenate operator to set its value, and then finally pass
the string to textext macro.

Is there a way to get around this issue?

On Sun, Mar 3, 2019, 1:13 PM Alan Braslau <braslau.list@comcast.net> wrote:

> On Sun, 3 Mar 2019 12:52:53 -0500
> Mohammad Hossein Bateni <bateni@gmail.com> wrote:
>
> > Hi,
> >
> > I can't understand why the following code does not work.  Could someone
> > help me out here?
> >
> > \starttext
> > \startMPpage
> > draw textext("\convertnumber{r}{12}");
> > draw textext("\convertnumber{r}{" & "12" & "}");
> > \stopMPpage
> > \stoptext
> >
> > The first draw statement works perfectly.  But the second one throws out
> > errors and complains as follows:
>
> Because luatex intercepts and processes \convertnumber{r}{
> and tries to pass this result to MP as a string, not the other way around.
>
> Alan
>