DaoFP Chapter 8 Exercises

exercise

Exercises from DaoFP, Chapter 8. Solutions: DaoFP Chapter 8 Solutions. Index: Map of Content.

Exercise 8.2.1

Describe a functor out of the Walking Arrow category $a\stackrel{f}{\to }b$.

Sources: DaoFP Exercise 8.2.1.

Solution: Solution 8.2.1

Exercise 8.2.2

Show a functor from the “walking iso” ($a\rightleftarrows b$ with $g\circ f={\mathrm{id}}_a$, $f\circ g={\mathrm{id}}_b$) picks an isomorphism.

Sources: DaoFP Exercise 8.2.2.

Solution: Solution 8.2.2

Exercise 8.3.1

Show data WithInt a = WithInt a Int is a Functor.

Sources: DaoFP Exercise 8.3.1.

Solution: Solution 8.3.1

Exercise 8.3.2

Show Identity is a Functor.

Sources: DaoFP Exercise 8.3.2.

Solution: Solution 8.3.2

Exercise 8.3.3

Show Constant c is a Functor (in its second argument).

Sources: DaoFP Exercise 8.3.3.

Solution: Solution 8.3.3

Exercise 8.3.4

Show data MoreThanA a b = More a (Maybe b) is a Bifunctor.

Sources: DaoFP Exercise 8.3.4.

Solution: Solution 8.3.4

Exercise 8.5.1

Define the composition of a Functor after a Contravariant functor.

Sources: DaoFP Exercise 8.5.1.

Solution: Solution 8.5.1