class Sass::Tree::Visitors::DeepCopy

def visit(node)
  super(node.dup)
end

def visit_children(parent)
  parent.children = parent.children.map {|c| visit(c)}
  parent
end

def visit_debug(node)
  node.expr = node.expr.deep_copy
  yield
end

def visit_directive(node)
  node.value = node.value.map {|c| c.is_a?(Sass::Script::Tree::Node) ? c.deep_copy : c}
  yield
end

def visit_each(node)
  node.list = node.list.deep_copy
  yield
end

def visit_error(node)
  node.expr = node.expr.deep_copy
  yield
end

def visit_extend(node)
  node.selector = node.selector.map {|c| c.is_a?(Sass::Script::Tree::Node) ? c.deep_copy : c}
  yield
end

def visit_for(node)
  node.from = node.from.deep_copy
  node.to = node.to.deep_copy
  yield
end

def visit_function(node)
  node.args = node.args.map {|k, v| [k.deep_copy, v && v.deep_copy]}
  yield
end

def visit_if(node)
  node.expr = node.expr.deep_copy if node.expr
  node.else = visit(node.else) if node.else
  yield
end

def visit_media(node)
  node.query = node.query.map {|c| c.is_a?(Sass::Script::Tree::Node) ? c.deep_copy : c}
  yield
end

def visit_mixin(node)
  node.args = node.args.map {|a| a.deep_copy}
  node.keywords = Sass::Util::NormalizedMap.new(Hash[node.keywords.map {|k, v| [k, v.deep_copy]}])
  yield
end

def visit_mixindef(node)
  node.args = node.args.map {|k, v| [k.deep_copy, v && v.deep_copy]}
  yield
end

def visit_prop(node)
  node.name = node.name.map {|c| c.is_a?(Sass::Script::Tree::Node) ? c.deep_copy : c}
  node.value = node.value.map {|c| c.is_a?(Sass::Script::Tree::Node) ? c.deep_copy : c}
  yield
end

def visit_return(node)
  node.expr = node.expr.deep_copy
  yield
end

def visit_rule(node)
  node.rule = node.rule.map {|c| c.is_a?(Sass::Script::Tree::Node) ? c.deep_copy : c}
  yield
end

def visit_supports(node)
  node.condition = node.condition.deep_copy
  yield
end

def visit_variable(node)
  node.expr = node.expr.deep_copy
  yield
end

def visit_warn(node)
  node.expr = node.expr.deep_copy
  yield
end

def visit_while(node)
  node.expr = node.expr.deep_copy
  yield
end