// ============================================================================
// 030 — Collection Algorithms
// ============================================================================
// Higher-level operations: group_by, unique counting, frequency analysis.
//
// Run:   soma run 030_collection_algorithms.cell run
// Expect:
//   Grouped by dept:
//     Eng: [{"dept": "Eng", "name": "Alice"}, {"dept": "Eng", "name": "Bob"}]
//     Sales: [{"dept": "Sales", "name": "Carol"}]
//   Unique departments: [{"dept": "Eng"}, {"dept": "Sales"}]
//   Engineers: 2

cell CollectionAlgorithms {

    on run() {
        let employees = list(
            map("dept", "Eng", "name", "Alice"),
            map("dept", "Eng", "name", "Bob"),
            map("dept", "Sales", "name", "Carol")
        )

        // group_by() returns a map of field_value -> list
        let grouped = group_by(employees, "dept")
        print("Grouped by dept:")
        print("  Eng: {grouped.Eng}")
        print("  Sales: {grouped.Sales}")

        // distinct() for unique values
        let unique = distinct(employees, "dept")
        print("Unique departments: {unique}")

        // count_by() counts occurrences of a specific value
        let eng_count = count_by(employees, "dept", "Eng")
        print("Engineers: {eng_count}")

        return "done"
    }
}