
30 Jun
2011
30 Jun
'11
10:58 p.m.
GHCi seems to be clever about some things: If I try to print the empty list in ghci, I encounter no problems: Prelude> [] [] Prelude> show [] "[]" Prelude> print [] [] Even though the type of the list is clearly unknown, it must be picking SOME type. (why does it print [] instead of "")? If I write a program in a file and load it in main = print [] Then I get the ambiguous type variable error that I would expect. Why doesn't ghci generate this error at the prompt? -- Borrow my books: http://goo.gl/UBbSH