Unison provides a variety of data types for managing collections of values. We'll show the basics of how to create instances of common collection types here.
Lists
One of the common things you'll be doing as a Unison programmer is managing ordered collections of one type or another. One of Unison's native data structures for this is List
, which we can create between square brackets.
desserts : [Text]
desserts = ["Eclair", "Peach cobbler", "Ice cream"]
Lists can only contain values of one type at a time, and are eagerly evaluated.
An empty list is simply represented []
or with List.empty
.
For the curious, the documentation for List
describes the underlying data structure and details many of the common operations you might perform with it.
Maps
The Map
type is Unison's way of mapping unique keys to values.
You can create a map with a single object with Map.singleton 1 "a"
where 1
is the key and "a"
is the value associated with that key.
Currently Unison does not have special Map
construction syntax so one easy way to create a multi-item map is from a List
of tuples
Check out the Map
documentation with docs Map
in the UCM.
Sets
You can create a Set
from a list of elements with the Set.fromList
constructor
Creating a Set
value enables efficient functions like Set.contains
and Set.union
that you might be familiar with from other languages.
You can explore these types and more collection apis in the base
library.