3 Jun
2011
3 Jun
'11
9:01 a.m.
-- followed by a symbol does not start a comment, thus for example, haddock declarations must begin with -- |, and not --|.
What might --| mean, if not a comment? It doesn't seem possible to define it as an operator.
GHCi, at least, allows it.
Prelude> let (--|) = (+) Prelude> 1 --| 2 3
I believe the motivating example that persuaded the Language Committee to allow these symbols was --> which is not of course used anywhere in the standard libraries, but is an extremely nice symbol to have available in user code. Regards, Malcolm