map -is:exact is:module -is:exact -is:exact -is:exact package:daml-stdlib

Note: This is only supported in Daml-LF 1.11 or later. This module exports the generic map type `Map k v` and associated functions. This module should be imported qualified, for example: ``` import DA.Map (Map) import DA.Map qualified as M ``` This will give access to the `Map` type, and the various operations as `M.lookup`, `M.insert`, `M.fromList`, etc. `Map k v` 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 map operations. It is recommended to only use `Map k v` 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.

TextMap - A map is an associative array data type composed of a collection of key/value pairs such that, each possible key appears at most once in the collection.