[racket-dev] very unhelpful beginner language error message, possible fix proposed

>
> "Ho Ho!" thought I. "Beginner Student Racket will give a much better error message." Actually, though, the error message was much worse: it highlighted the id "list-sum-odd" in what should have been the 'else' case, and wrote:
>
> "list-sum-odd: expected a function call, but there is no open parenthesis before this function"
>
> ... which is really terrible, because there *IS* a parenthesis right before the function name.


This is a variation of one of the cases described in Guillaume's paper
on error messages.  Figure 4 of
http://gmarceau.qc.ca/papers/Marceau-2010-Measuring-Effectiveness.pdf