~ symbol

Cagdas Ozgenc co19@cornell.edu
Wed, 29 Aug 2001 12:06:37 +0300


Hello,

What is the use of ~ symbol in Haskell? For example in prelude function
unzip

unzip = foldr (\(a,b) ~(as,bs) -> (a:as, b:bs)) ([], [])

It works fine without the tilda. Is the use of tilda specific to lambda
expression?

Thanks