Extracting constructor name

[Gracjan Polak]

Hi all,

To get a bit better error reporting and debugging I'd like to report constructor
names misused. Example:


data X = A | B Int | C String


magic A = doSomething
magic x = error $ "magic can only be used on A, you supplied " ++ constrName x

I'm missing constrName that returns only constructor name as string, skips all
fields (if any).

-- 
Gracjan