> List,
>     I still cannot figure out why the assert instruction
> does not return the line number at which the exception occures.

Basically, it's because the compiler uses character numbers
internally; line numbers are computed only when printing an error message.

> The characters are no good to me in debugging. I suppose they make
> sense from the compiler's point of view, but they are no use to me. 

With Emacs, it's as easy to jump to a character number (M-x goto-char)
than to jump to a line number (M-x goto-line).  Since we (the OCaml
developers) are Emacs fans, we didn't think that character numbers
might be a problem for some users.

- Xavier Leroy