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Let and where constructs

Hard differences

let constructs are legal

example code:

main = print (1 + (let i = 10 in 2 * i + 1))

where constructs are ilegal

example code:

main = print (1 + (2 * i + 1 where i = 10))

where constructs are legal

example code:

hasVowel [] = False
hasVowel (x:xs)
  | x `elem` vowels = True
  | otherwise = False
  where vowels = "AEIOUaeiou"

let constructs are ilegal

example code:

let vowels = "AEIOUaeiou"
in hasVowel = ...

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