Our first data model

We're using Immuto because we want all our data to be immutable. For a really simple example we'll go with:

export interface Person {
    readonly firstName: string;
    readonly lastName: string;
    readonly trusted: boolean;
}

Looks like we have trust issues. But anyway. Save the above into your project directory as Person.ts.

Now let's describe this structure to Immuto. At the top of the file add:

import { property, reducer } from "immuto";

Then at the bottom continue with:

export namespace Person {

    export const empty: Person = {
        firstName: "",
        lastName: "",
        trusted: false
    };

    export const firstName = property("FIRST_NAME", (p: Person) => p.firstName);
    export const lastName = property("LAST_NAME", (p: Person) => p.lastName);
    export const trusted = property("TRUSTED", (p: Person) => p.trusted);

    export const reduce = reducer(empty)
        .action(firstName)
        .action(lastName)
        .action(trusted);

    export type Cursor = typeof reduce.cursorType;
}

We've declared an empty Person (not saying they're emotionally empty.) Then we've declared property helpers for each of the properties we want user to be able to independently edit, giving each one a Redux-style all-caps name.

Then we create the reduce function. This is the crux of the Redux approach, but here Immuto writes the function for us.

The last part, where we declare a type alias called Cursor, is hard to explain at this point, but we'll get to it soon.