til/reason/create-a-map-of-strings.md

Create A Map Of Strings

ReasonML has the Map.Make functor in its standard library which allows you to create a Map module with a specific key type. Here is how we can make a map module with string keys.

module StringMap = Map.Make(String);

We can then use that module to to create an empty map followed by adding key-value pairs to it.

StringMap.empty
|> StringMap.add("Morty", "Smith")
|> StringMap.add("Rick", "Sanchez")
|> StringMap.add("Scary", "Terry")
|> StringMap.iter((first, last) => {
  print_endline(Printf.sprintf("%s %s", first, last));
});
/*
Morty Smith
Rick Sanchez
Scary Terry
*/

See the live example.