GHCi “let” — what does it do?

Question

I\'d appreciate if someone could point to docs on what "let" does in GHCi, or failing that, explain it convincingly.

So far as I can tell, "let" (

Answer 1

GHCI commands are executed in the IO monad and uses do syntax, so the desugaring rules apply. From Real World Haskell

doNotation4 =
    do let val1 = expr1
           val2 = expr2
           {- ... etc. -}
           valN = exprN
       act1
       act2
       {- ... etc. -}
       actN

translates to:

translated4 =
    let val1 = expr1
        val2 = expr2
        {- ... etc. -}
        valN = exprN
    in do act1
          act2
          {- ... etc. -}
          actN