signatures interfere with structures in ISL

[mfelleisen]

See racket/racket#1976 for details.

@ccshan
@schackbrian2012

edit: added URL to racket issue ref

[mikesperber]

I just pushed a patch to deinprogramm-signature that has a custom error message for this situation:

function call: expected a function after the parenthesis, but received a signature

I'm sure it's not optimal, so happy to hear suggestions for improvement.

[mfelleisen]

Thanks! This should work fine. I would probably have used the error message rewriter to fix up the message.

[schackbrian2012]

Thank you for changing the error message!

[mikesperber]

Closing this one as it's been addressed.