[Haskell-beginners] Parse error in pattern

[Brent Yorgey]

On Sun, Jan 08, 2012 at 12:11:29AM +0800, Zhi-Qiang Lei wrote:
> 
> scan :: [Point a] -> [Point a]
> scan p1 : p2 : p3 : xs

Patterns with constructors and multiple components must be surrounded
by parentheses.  So this should be

  scan (p1 : p2 : p3 : xs)

-Brent