Relude.Container.One · relude-1.2.0.0

classclass One x where

Typeclass for data types that can be created from one element. E.g. lists, non-empty containers, maps.

Example3 expressions

>>> one True :: [Bool][True]>>> one 'a' :: Text"a">>> one (3, "hello") :: HashMap Int StringfromList [(3,"hello")]

Laws:

single-size: ∀ x . size (one x) ≡ 1

(where size is a specific function for each container that returns the size of this container)

Associated types

type family OneItem x
Type of a single element of the structure.

Methods

one :: OneItem x -> x
Create a list, map, Text, etc from a single element.

Instances14One, …

One ByteStringDefined in relude-1.2.0.0 · Relude.Container.One
Create singleton strict ByteString.
Example1 expression
```
>>> one 97 :: ByteString"a"
```
```
law> length (one x) ≡ 1
```
One ByteStringDefined in relude-1.2.0.0 · Relude.Container.One
Create singleton lazy ByteString.
Example1 expression
```
>>> one 97 :: LByteString"a"
```
```
law> length (one x) ≡ 1
```
One ShortByteStringDefined in relude-1.2.0.0 · Relude.Container.One
Create singleton ShortByteString.
Example1 expression
```
>>> one 97 :: ShortByteString"a"
```
```
law> length (one x) ≡ 1
```
One IntSetDefined in relude-1.2.0.0 · Relude.Container.One
Create singleton IntSet.
Example1 expression
```
>>> one 42 :: IntSetfromList [42]
```
```
law> size (one x) ≡ 1
```
One TextDefined in relude-1.2.0.0 · Relude.Container.One
Create singleton strict Text.
Example1 expression
```
>>> one 'a' :: Text"a"
```
```
law> length (one x) ≡ 1
```
One TextDefined in relude-1.2.0.0 · Relude.Container.One
Create singleton lazy Text.
Example1 expression
```
>>> one 'a' :: LText"a"
```
```
law> length (one x) ≡ 1
```
Hashable a => One (HashSet a)Defined in relude-1.2.0.0 · Relude.Container.One
Create singleton HashSet.
Example1 expression
```
>>> one 42 :: HashSet IntfromList [42]
```
```
law> Relude.length (one @(HashSet a) x) ≡ 1
```
One (IntMap v)Defined in relude-1.2.0.0 · Relude.Container.One
Create singleton IntMap from key-value pair.
Example1 expression
```
>>> one (3, "foo") :: IntMap TextfromList [(3,"foo")]
```
```
law> Relude.length (one @(IntMap a) x) ≡ 1
```
One (Seq a)Defined in relude-1.2.0.0 · Relude.Container.One
Create singleton Seq.
Example1 expression
```
>>> one 42 :: Seq IntfromList [42]
```
```
law> Relude.length (one @(Seq a) x) ≡ 1
```
One (Set a)Defined in relude-1.2.0.0 · Relude.Container.One
Create singleton Set.
Example1 expression
```
>>> one 42 :: Set IntfromList [42]
```
```
law> Relude.length (one @(Set a) x) ≡ 1
```
One (NonEmpty a)Defined in relude-1.2.0.0 · Relude.Container.One
Allows to create singleton NonEmpty list. You might prefer function with name one instead of Relude.pure or (:|[]).
Example1 expression
```
>>> one 42 :: NonEmpty Int42 :| []
```
```
law> Relude.length (one @(NonEmpty a) x) ≡ 1
```
One [a]Defined in relude-1.2.0.0 · Relude.Container.One
Allows to create a singleton list. You might prefer function with name one instead of Relude.pure or (:[]).
Example1 expression
```
>>> one 42 :: [Int][42]
```
```
law> Relude.length (one @[a] x) ≡ 1
```
Hashable k => One (HashMap k v)Defined in relude-1.2.0.0 · Relude.Container.One
Create singleton HashMap from key-value pair.
Example1 expression
```
>>> one (3, "foo") :: HashMap Int TextfromList [(3,"foo")]
```
```
law> Relude.length (one @(HashMap k v) (k, v)) ≡ 1
```
One (Map k v)Defined in relude-1.2.0.0 · Relude.Container.One
Create singleton Map from key-value pair.
Example1 expression
```
>>> one (3, "foo") :: Map Int TextfromList [(3,"foo")]
```
```
law> Relude.length (one @(Map k v) (k, v)) ≡ 1
```