[Haskell] Strange "let"

Jinwoo Lee blue6811 at freechal.com
Wed Jul 21 01:36:54 EDT 2004

I'm a Haskell newbie.
I was trying several things with GHCi and found out that the expression "let
a + b = 3" does not generate any errors.
Prelude> let a + b = 3
Prelude> a

<interactive>:1: Variable not in scope: `a'
Prelude> b

<interactive>:1: Variable not in scope: `b'

What does "let a + b = 3" mean in this case?

I also tries with GHC compiler using the code below, but it generates no

main :: IO ()
main =
  do let a + b = 3
     putStrLn "Hello"

Could somebody answer this?


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