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