Filter and Sort Pipelines

031_filter_sort.cell

// ============================================================================
// 031 — Filter and Sort Pipelines
// ============================================================================
// filter_by() and sort_by() are the building blocks of data pipelines.
//
// Run:   soma run 031_filter_sort.cell run
// Expect:
//   Expensive items (price > 50):
//     Laptop: 999
//     Phone: 699
//     Tablet: 449
//   Sorted by price ascending:
//     Mouse: 29
//     Keyboard: 49
//     Tablet: 449
//     Phone: 699
//     Laptop: 999

cell FilterSort {

    on run() {
        let products = list(
            map("name", "Laptop", "price", 999),
            map("name", "Mouse", "price", 29),
            map("name", "Keyboard", "price", 49),
            map("name", "Phone", "price", 699),
            map("name", "Tablet", "price", 449)
        )

        // filter_by(list, field, operator, value)
        // Operators: "=", "!=", ">", "<", ">=", "<="
        let expensive = filter_by(products, "price", ">", 50)
        print("Expensive items (price > 50):")
        for item in expensive {
            print("  {item.name}: {item.price}")
        }

        // sort_by(list, field, direction)
        // Direction: "asc" or "desc"
        let sorted = sort_by(products, "price", "asc")
        print("Sorted by price ascending:")
        for item in sorted {
            print("  {item.name}: {item.price}")
        }

        return "done"
    }
}