> parse "3.1"
Right (Real 3.1)


> parse "add A2,B3"
Left (Formula Add (Pair { left = { col = 1, row = 0 }, right = { col = 2, row = 1 } }))


> parse "add A2:A8"
Left (Formula Add (Range { left = { col = 1, row = 0 }, right = { col = 7, row = 0 } }))mula Add (Pair { left = { col = 1, row = 0 }, right = { col = 7, row = 0 } }))


> parse "add B3:B9"
Left (Formula Add (Range { left = { col = 2, row = 1 }, right = { col = 8, row = 1 } }))

> run C.parseIndex "a2"
Ok { col = 1, row = 0 }