I want to read a text file, and store it in a String. But readFile will get IO String. I search with google and they tell me it is not necessarily to do so. Can you explain to me why is this? Furthermore, How to read a file and store it in a String?

In fact, I want to read a file and split it into [String] with lines function. Here is what I have tried. link I think I could directly operate on [String]. But it is not true for me.


[1] http://www.haskell.org/hoogle/?hoogle=IO+String+-%3E+String


Yi Lu