HashSet -package:unordered-containers

A set of values. A set cannot contain duplicate values.

Set with hashed members. Import as:

import qualified RIO.HashSet as HS

Persistent Set based on hashing, which is defined as

data Set e = IntMap (Some e)

is an IntMap indexed by hash values of elements, containing a value of Some e. That contains either one e or a Set e with elements of the same hash values. The interface of a Set is a suitable subset of IntSet and can be used as a drop-in replacement of Set. The complexity of operations is determined by the complexities of IntMap and Set operations. See the sources of Set to see which operations from containers package are used.

Deprecated: HashSet is deprecated. Please use Set instead.

A set of values. A set cannot contain duplicate values.

A HashSet whose contents are tracked by the type parameter s. This is a "singleton": for a given s there's only one value of this type. Since this is just a Dict, you can freely convert between the value (HashSet) and the constraint (KnownHashSet). This library prefers to use the constraint.

Fold values into a hash-set

This is a slight lie, as roundtrip doesn't preserve ordering.

Codec for HashSet of values. Represented in TOML as an array of tables. Example: Haskell HashSet Int can look like this in your TOML file:

foo =
[ {a = 1}
, {a = 2}
]

Decodes to an empty HashSet in case of the missing field in TOML.

Decode a HashSet from a List with distinct elements.

>>> input (hashSetFromDistinctList natural) "[1, 2, 3]"
fromList [1,2,3]

An error is thrown if the list contains duplicates.

>>> input (hashSetFromDistinctList natural) "[1, 1, 3]"
*** Exception: Error: Failed extraction

The expression type-checked successfully but the transformation to the target
type failed with the following error:

One duplicate element in the list: 1

>>> input (hashSetFromDistinctList natural) "[1, 1, 3, 3]"
*** Exception: Error: Failed extraction

The expression type-checked successfully but the transformation to the target
type failed with the following error:

2 duplicates were found in the list, including 1

Decode a HashSet from a List.

>>> input (hashSetIgnoringDuplicates natural) "[1, 2, 3]"
fromList [1,2,3]

Duplicate elements are ignored.

>>> input (hashSetIgnoringDuplicates natural) "[1, 1, 3]"
fromList [1,3]

HashSet which tries its best to remember insertion order of elements.

Takes a BiMap of a value and returns a BiMap for a HashSet of values and AnyValue as an array. Usually used as the arrayHashSetOf combinator.

Codec for hash sets. Takes converter for single hashable value and returns a set of hashable values. Example: Haskell HashSet Int can look like this in your TOML file:

foo = [1, 2, 3]

In case of the missing field, the following error will be seen:

tomland decode error:  Key foo is not found