Hi Jochen, you seem to be back on the mailing lists, so here is a pending question for you.
I was comparing the source position of assert statement case with some other statements and noticed that for other cases the position of the ':' token was getting set on the statement but the actual position was getting carried by the expressions inside them. Whereas in case of AssertStatement, it was having an impact because Power-Assert code uses the source position from the AssertStatement itself, which is wrong.
So, by comparison, one potential solution could be to have a AssertExpression wrapped inside a AssertStatement, and make assert code use the source position from AssertExpression instead of AssertExpression.
Do you think it is a worthwhile thing to try that change? Or, do you see a simpler solution?