Sergey, I could not agree more. I sent the following message to the
Hugs implementors a few months ago.....
I have taught Hugs for a couple of years and enjoy using it. Students
like to have a system they can take home and install for free, and the
system seems pretty robust. One problem students do have, however, is
with error messages, which often leave a bit to be desired. An incorrectly
terminated block of definitions can lead to the message
ERROR "test.lhs" (line 2): Syntax error in input (unexpected `;')
for a file in which there is no a `;' in sight. Using = for an equality
comparison instead of == leads to the magisterial
ERROR "test.lhs" (line 6): Attempt to use Typed Records with Extensions
while parsing an expression. This feature is disabled in this build of Hugs.
To help students I have compiled a list of messages and examples of code that
provoke them. In many cases a little effort would, I guess, lead to vastly
more informative error messages. I'd be interested to hear what you (and the
Hugs group) think. The catalogue of errors is at
http://www.cs.ukc.ac.uk/people/staff/sjt/craft2e/errors.html
Regards
Simon Thompson
