feat: add DataTable and DataList classes with basic functionality

lab2/data_table.rb

@@ -0,0 +1,63 @@
+class DataTable
+  def initialize(data)
+    @data = data.map { |row| row.dup.freeze }.freeze
+  end
+
+  def item(row, col)
+    return nil unless valid_row?(row) && valid_col?(col)
+    @data[row][col]
+  end
+
+  def rows_count
+    @data.size
+  end
+
+  def columns_count
+    return 0 if @data.empty?
+    @data.first.size
+  end
+
+  private
+
+  def valid_row?(row)
+    row.between?(0, rows_count - 1)
+  end
+
+  def valid_col?(col)
+    col.between?(0, columns_count - 1)
+  end
+end
+
+class DataList
+  def initialize(items)
+    @items = items.dup.freeze
+    @selected = []
+  end
+
+  def select(number)
+    index = number.to_i
+    toggle_selection(index) if valid_index?(index)
+  end
+
+  def get_selected
+    @selected.dup
+  end
+
+  def get_names
+    raise NotImplementedError, "Implement this method in a subclass"
+  end
+
+  def get_data
+    raise NotImplementedError, "Implement this method in a subclass"
+  end
+
+  private
+
+  def valid_index?(index)
+    index.between?(0, @items.size - 1)
+  end
+
+  def toggle_selection(index)
+    @selected.include?(index) ? @selected.delete(index) : @selected << index
+  end
+end

lab2/test_data_table.rb

@@ -0,0 +1,39 @@
+require_relative 'data_table'
+
+data = [
+  [1, "Alice", 25],
+  [2, "Bob", 30],
+  [3, "Charlie", 35]
+]
+
+data_table = DataTable.new(data)
+
+puts "Количество строк: #{data_table.rows_count}" # Ожидаем 3
+puts "Количество столбцов: #{data_table.columns_count}" # Ожидаем 3
+puts "Элемент в строке 1, столбце 2: #{data_table.item(1, 2)}" # Ожидаем 30
+puts "Элемент в строке 0, столбце 1: #{data_table.item(0, 1)}" # Ожидаем "Alice"
+puts "Элемент за пределами таблицы: #{data_table.item(10, 10)}" # Ожидаем nil
+
+items = [
+  { id: 1, name: "Alice", age: 25 },
+  { id: 2, name: "Bob", age: 30 },
+  { id: 3, name: "Charlie", age: 35 }
+]
+
+data_list = DataList.new(items)
+
+data_list.select(0)
+data_list.select(2)
+puts "Выбранные элементы: #{data_list.get_selected.inspect}"
+
+begin
+  data_list.get_names
+rescue NotImplementedError => e
+  puts "Ошибка: #{e.message}" # Ожидаем "Implement this method in a subclass"
+end
+
+begin
+  data_list.get_data
+rescue NotImplementedError => e
+  puts "Ошибка: #{e.message}" # Ожидаем "Implement this method in a subclass"
+end