class Arel::DeleteManager

def from(relation)
  @ast.relation = relation
  self
end

def group(columns)
  columns.each do |column|
    column = Nodes::SqlLiteral.new(column) if String === column
    column = Nodes::SqlLiteral.new(column.to_s) if Symbol === column
    @ast.groups.push Nodes::Group.new column
  end
  self
end

def having(expr)
  @ast.havings << expr
  self
end

def initialize(table = nil)
  @ast = Nodes::DeleteStatement.new(table)
end