Data.NonNull

A monomorphic container that is not null.

Safely convert from an unsafe monomorphic container to a safe non-null monomorphic container.

Unsafely convert from an unsafe monomorphic container to a safe non-null monomorphic container.

Throws an exception if the monomorphic container is empty.

Old synonym for impureNonNull

Safely convert from a non-null monomorphic container to a nullable monomorphic container.

Safely convert from a NonEmpty list to a non-null monomorphic container.

Safely convert from a NonNull container to a NonEmpty list.

Prepend an element to a SemiSequence, creating a non-null SemiSequence.

Generally this uses cons underneath. cons is not efficient for most data structures.

Alternatives:

• if you don't need to cons, use fromNullable or nonNull if you can create your structure in one go.

• if you need to cons, you might be able to start off with an efficient data structure such as a NonEmpty List. fromNonEmpty will convert that to your data structure using the structure's fromList function.

Extract the first element of a sequence and the rest of the non-null sequence if it exists.

Same as nuncons with no guarantee that the rest of the sequence is non-null.

Equivalent to Data.Sequences.filter, but works on non-nullable sequences.

Equivalent to Data.Sequences.filterM, but works on non-nullable sequences.

Equivalent to Data.Sequences.replicate

i must be > 0

i <= 0 is treated the same as providing 1

Return the first element of a monomorphic container.

Safe version of headEx, only works on monomorphic containers wrapped in a NonNull.

Safe version of tailEx, only working on non-nullable sequences.

Return the last element of a monomorphic container.

Safe version of lastEx, only works on monomorphic containers wrapped in a NonNull.

Safe version of initEx, only working on non-nullable sequences.

Map each element of a monomorphic container to a semigroup, and combine the results.

Safe version of ofoldMap1Ex, only works on monomorphic containers wrapped in a NonNull.

Examples

> let xs = ncons ("hello", 1 :: Integer) [(" world", 2)]
> ofoldMap1 fst xs
"hello world"

Join a monomorphic container, whose elements are Semigroups, together.

Safe, only works on monomorphic containers wrapped in a NonNull.

Examples

> let xs = ncons "a" ["b", "c"]
> xs
NonNull {toNullable = ["a","b","c"]}

> ofold1 xs
"abc"

Right-associative fold of a monomorphic container with no base element.

Safe version of ofoldr1Ex, only works on monomorphic containers wrapped in a NonNull.

foldr1 f = Prelude.foldr1 f . otoList

Examples

> let xs = ncons "a" ["b", "c"]
> ofoldr1 (++) xs
"abc"

Strict left-associative fold of a monomorphic container with no base element.

Safe version of ofoldl1Ex', only works on monomorphic containers wrapped in a NonNull.

foldl1' f = Prelude.Prelude.foldl1' f . otoList

Examples

> let xs = ncons "a" ["b", "c"]
> ofoldl1' (++) xs
"abc"

Get the maximum element of a monomorphic container.

Safe version of maximumEx, only works on monomorphic containers wrapped in a NonNull.

Examples

> let xs = ncons 1 [2, 3 :: Int]
> maximum xs
3

Get the maximum element of a monomorphic container, using a supplied element ordering function.

Safe version of maximumByEx, only works on monomorphic containers wrapped in a NonNull.

Get the minimum element of a monomorphic container.

Safe version of minimumEx, only works on monomorphic containers wrapped in a NonNull.

Examples

> let xs = ncons 1 [2, 3 :: Int]
> minimum xs
1

Get the minimum element of a monomorphic container, using a supplied element ordering function.

Safe version of minimumByEx, only works on monomorphic containers wrapped in a NonNull.

Prepend an element to a non-null SemiSequence.

Specializes fromNonEmpty to lists only.

fmap over the underlying container in a NonNull.

Containers which, when two values are combined, the combined length is no less than the larger of the two inputs. In code:

olength (x <> y) >= max (olength x) (olength y)

This class has no methods, and is simply used to assert that this law holds, in order to provide guarantees of correctness (see, for instance, Data.NonNull).

This should have a Semigroup superclass constraint, however, due to Semigroup only recently moving to base, some packages do not provide instances.