The questions for this chapter were:

Exercises

• Lambdas are a nice way to avoid defining unnecessary separate functions. Convert the following let- or where-bindings to lambdas:
  • map f xs where f x = x * 2 + 3

map (\ x -> x * 2 + 3) xs

• • let f x y = read x + y in foldr f 1 xs

foldr (\ x y -> read x + y) 1 xs

• • Sections are just syntactic sugar for lambda operations. I.e. (+2) is equivalent to \x -> x + 2. What would the following sections 'desugar' to? What would be their types?
  • (4+)

\x -> 4 + x

• • (1 `elem`)

\x -> elem 1 x

• • (`notElem` "abc")

\x -> notElem x "abc"