| i ≥ 0 ∧ i < 100 = B.fromByteString "0" ⊕ BT.integral i
| i ≥ 0 ∧ i < 1000 = BT.integral i
| otherwise = error ("show3: the integer i must satisfy 0 <= i < 1000: " ⧺ show i)
+-- FIXME: Drop this function as soon as possible, to eliminate the
+-- dependency on blaze-textual.