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DA.Set

Note: This is only supported in Daml-LF 1.11 or later. This module exports the generic set type Set k and associated functions. This module should be imported qualified, for example: 

import DA.Set (Set)

import DA.Set qualified as S
This will give access to the Set type, and the various operations as S.lookup, S.insert, S.fromList, etc. Set k internally uses the built-in order for the type k. This means that keys that contain functions are not comparable and will result in runtime errors. To prevent this, the Ord k instance is required for most set operations. It is recommended to only use Set k for key types that have an Ord k instance that is derived automatically using deriving: 

data K = ...

deriving (Eq, Ord)
This includes all built-in types that aren’t function types, such as Int, Text, Bool, (a, b) assuming a and b have default Ord instances, Optional t and [t] assuming t has a default Ord instance, Map k v assuming k and v have default Ord instances, and Set k assuming k has a default Ord instance.

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Module Snapshot

Lifecycle

Stable.

Notices

Status: active Introduced in: 3.4.9 Removed in: - Warnings: 0 Deprecations: 0 Deprecated since: -

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Data Types

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data Set k

The type of a set. This is a wrapper over the Map type. Constructors:
  • Set | Field | Type | Description | | :---- | :--- | :---------- | | map | Map k () | |
Instances:
  • instance Foldable Set
  • instance Ord k => Monoid (Set k)
  • instance Ord k => Semigroup (Set k)
  • instance GetField map (Set k) (Map k ())
  • instance SetField map (Set k) (Map k ())
  • instance IsParties (Set Party)
  • instance Ord k => Eq (Set k)
  • instance Ord k => Ord (Set k)
  • instance (Ord k, Show k) => Show (Set k)

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Functions

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empty

empty : Set k
The empty set.

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size

size : Set k -> Int
The number of elements in the set.

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toList

toList : Set k -> [k]
Convert the set to a list of elements.

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fromList

fromList : Ord k => [k] -> Set k
Create a set from a list of elements.

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toMap

toMap : Set k -> Map k ()
Convert a Set into a Map.

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fromMap

fromMap : Map k () -> Set k
Create a Set from a Map.

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member

member : Ord k => k -> Set k -> Bool
Is the element in the set?

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notMember

notMember : Ord k => k -> Set k -> Bool
Is the element not in the set? notMember k s is equivalent to not (member k s).

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null

null : Set k -> Bool
Is this the empty set?

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insert

insert : Ord k => k -> Set k -> Set k
Insert an element in a set. If the set already contains the element, this returns the set unchanged.

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filter

filter : Ord k => (k -> Bool) -> Set k -> Set k
Filter all elements that satisfy the predicate.

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delete

delete : Ord k => k -> Set k -> Set k
Delete an element from a set.

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singleton

singleton : Ord k => k -> Set k
Create a singleton set.

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union

union : Ord k => Set k -> Set k -> Set k
The union of two sets.

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intersection

intersection : Ord k => Set k -> Set k -> Set k
The intersection of two sets.

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difference

difference : Ord k => Set k -> Set k -> Set k

`difference x y` returns the set consisting of all
elements in `x` that are not in `y`.

>>> fromList [1, 2, 3] `difference` fromList [1, 4]
fromList [2, 3]

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isSubsetOf

isSubsetOf : Ord k => Set k -> Set k -> Bool
isSubsetOf a b returns true if a is a subset of b, that is, if every element of a is in b.

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isProperSubsetOf

isProperSubsetOf : Ord k => Set k -> Set k -> Bool
isProperSubsetOf a b returns true if a is a proper subset of b. That is, if a is a subset of b but not equal to b.

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Orphan Typeclass Instances

  • instance Ord k => Eq (Set k)
  • instance Ord k => Ord (Set k)
  • instance (Ord k, Show k) => Show (Set k)
  • instance IsParties (Set Party)
  • instance Ord k => Semigroup (Set k)
  • instance Ord k => Monoid (Set k)
  • instance GetField map (Set k) (Map k ())
  • instance SetField map (Set k) (Map k ())
  • instance Foldable Set