Top N Analysis

038_top_n.cell

// ============================================================================
// 038 — Top N Analysis
// ============================================================================
// top() takes the first N rows from a (usually sorted) list.
//
// Run:   soma run 038_top_n.cell run
// Expect:
//   Top 3 by population:
//     Tokyo: 37400000
//     Delhi: 30290000
//     Shanghai: 27058000
//   Bottom 2 by population:
//     Osaka: 19281000
//     Cairo: 20076000

cell TopN {

    on run() {
        let cities = list(
            map("name", "Tokyo", "population", 37400000),
            map("name", "Delhi", "population", 30290000),
            map("name", "Shanghai", "population", 27058000),
            map("name", "Cairo", "population", 20076000),
            map("name", "Osaka", "population", 19281000)
        )

        // Top 3 by population (descending)
        let top3 = cities
            |> sort_by("population", "desc")
            |> top(3)

        print("Top 3 by population:")
        for city in top3 {
            print("  {city.name}: {city.population}")
        }

        // Bottom 2 (sort ascending, take top 2)
        let bottom2 = cities
            |> sort_by("population", "asc")
            |> top(2)

        print("Bottom 2 by population:")
        for city in bottom2 {
            print("  {city.name}: {city.population}")
        }

        return "done"
    }
}