CSV-Like Data Processing

071_csv_processing.cell

// ============================================================================
// 071 — CSV-Like Data Processing
// ============================================================================
// Parse and process tabular data represented as lists of maps.
//
// Run:   soma run 071_csv_processing.cell run
// Expect:
//   Loaded 5 employees
//   Eng employees: 2
//   Average salary: 96
//   CSV output:
//   name,dept,salary
//   Alice,Eng,120
//   Bob,Sales,80
//   Carol,Eng,95
//   Dave,Marketing,85
//   Eve,Sales,100

cell CsvProcessing {

    on run() {
        // Simulate loading CSV data as a list of maps
        let data = list(
            map("name", "Alice", "dept", "Eng", "salary", 120),
            map("name", "Bob", "dept", "Sales", "salary", 80),
            map("name", "Carol", "dept", "Eng", "salary", 95),
            map("name", "Dave", "dept", "Marketing", "salary", 85),
            map("name", "Eve", "dept", "Sales", "salary", 100)
        )

        let count = data.length
        print("Loaded {count} employees")

        // Filter and count
        let eng = data |> filter_by("dept", "=", "Eng")
        let eng_count = eng.length
        print("Eng employees: {eng_count}")

        // Average
        let avg = data |> avg_by("salary")
        print("Average salary: {avg}")

        // Generate CSV output
        print("CSV output:")
        print("name,dept,salary")
        for row in data {
            let salary_str = to_string(row.salary)
            let line = concat(row.name, concat(",", concat(row.dept, concat(",", salary_str))))
            print(line)
        }

        return "done"
    }
}