On Thu, 2 Feb 2006, Henrik Nilsson wrote:
Hi all,
To corroborate Wadler's law further.
Josef wrote:
Oh yes, it does happen that a single line comment begins with a special symbol. It has happened to me on several occations when using haddock annotation to my source code. It is all to easy to forget that extra space. With incomprehensible error messages as a result.
But might that not just mean that the error messages ought to be improved?
I don't know how hard that would be, but after having played around a bit with GHC, the messages I get are either of the type "parse error on input '--|'" or of the type "Not in scope: `-->'" (followed by lots of other stuff not being in scope etc).
If this really is a big problem for beginners, it would not seem totally infeasible to add some special code that helpfully suggests that a space perhaps ought to be inserted?
Or have you seen significantly worse error messages?
Well, if anecdotal evidence from a real live beginner would help, I've never had problems with the comments. I think I made that mistake once, looked at the line it failed on, and added the space.