typescript2.ts

namespace Structure {
    export type TabState = "impact" | "timeline" | "geography"; 
    export type OpState = "and" | "or"; 
 
    export interface AppState { 
        tab?: TabState, 
        op: OpState, 
        tags: Array<string>, 
    }
}

let app_state: Structure.AppState = {
    tab: "impact",
    op: "and",
    tags: ["artificial-intelligence", "unix", "lisp"],
}