case ast.SEND:
			children = append(children, tok(n.Begin, len("chan<-")))
		case ast.RECV | ast.SEND:
			children = append(children, tok(n.Begin, len("chan")))
		}

	case *ast.CommClause:
		if n.Comm == nil {
			children = append(children,
				tok(n.Case, len("default")))
		} else {
			children = append(children,
				tok(n.Case, len("case")))
		}

			}

		case *ast.CaseClause:
			blockBranches(nil, s.Body)

		case *ast.SwitchStmt:
			stmtBranches(s.Body)

		case *ast.TypeSwitchStmt:
			stmtBranches(s.Body)

		case *ast.CommClause:
			blockBranches(nil, s.Body)

		case *ast.SelectStmt:
			stmtBranches(s.Body)

		case *ast.ForStmt:
			stmtBranches(s.Body)

		case *ast.RangeStmt:
			stmtBranches(s.Body)
		}
	}

	case *RangeClause:
		if n.Lhs != nil {
			w.node(n.Lhs)
		}
		w.node(n.X)

	case *CaseClause:
		if n.Cases != nil {
			w.node(n.Cases)
		}
		w.stmtList(n.Body)

	case *CommClause:
		if n.Comm != nil {
			w.node(n.Comm)
		}
		w.stmtList(n.Body)

	default:
		panic(fmt.Sprintf("internal error: unknown node type %T", n))
	}

	w.v.Visit(nil)
}

		}
		if n.Tag != nil {
			Walk(v, n.Tag)
		}
		Walk(v, n.Body)

	case *TypeSwitchStmt:
		if n.Init != nil {
			Walk(v, n.Init)
		}
		Walk(v, n.Assign)
		Walk(v, n.Body)

	case *CommClause:
		if n.Comm != nil {
			Walk(v, n.Comm)
		}
		walkList(v, n.Body)

	case *SelectStmt:
		Walk(v, n.Body)

	case *ForStmt:
		if n.Init != nil {
			Walk(v, n.Init)
		}

	KindRangeDone       // block after RangeStmt
	KindRangeLoop       // head of RangeStmt
	KindSelectCaseBody  // body of SelectStmt
	KindSelectDone      // block after SelectStmt
	KindSelectAfterCase // block after a CommClause
	KindSwitchCaseBody  // body of CaseClause
	KindSwitchDone      // block after {Type.}SwitchStmt
	KindSwitchNextCase  // secondary expression of a multi-expression CaseClause
)

	}

	c.Colon = p.pos()
	p.want(_Colon)
	c.Body = p.stmtList()

	return c
}

func (p *parser) commClause() *CommClause {
	if trace {
		defer p.trace("commClause")()
	}

	c := new(CommClause)
	c.pos = p.pos()

	switch p.tok {
	case _Case:
		p.next()
		c.Comm = p.simpleStmt(nil, 0)

		p.print(newline)
		for i, c := range list {
			p.printCaseClause(c, i+1 == len(list))
			p.print(newline)
		}
	}
	p.print(_Rbrace)
}

func (p *printer) printSelectBody(list []*CommClause) {
	p.print(_Lbrace)
	if len(list) > 0 {
		p.print(newline)
		for i, c := range list {
			p.printCommClause(c, i+1 == len(list))
			p.print(newline)
		}
	}
	p.print(_Rbrace)
}

	case *ast.TypeSwitchStmt:
		for _, c := range s.Body.List {
			cc := c.(*ast.CaseClause)
			forEachLastStmt(cc.Body, onLast)
		}
	case *ast.SelectStmt:
		for _, c := range s.Body.List {
			cc := c.(*ast.CommClause)
			forEachLastStmt(cc.Body, onLast)
		}
	default:
		onLast(s)
	}
}

// litStmts returns all statements from the function body of a function
// literal.
//

	var first ast.Stmt
	for _, s := range list {
		var d ast.Stmt
		switch c := s.(type) {
		case *ast.CaseClause:
			if len(c.List) == 0 {
				d = s
			}
		case *ast.CommClause:
			if c.Comm == nil {
				d = s
			}
		default:
			check.error(s, InvalidSyntaxTree, "case/communication clause expected")
		}
		if d != nil {
			if first != nil {

				// TODO(gri) probably ok to bail out after first error (and simplify this code)
			} else {
				first = c
			}
		}
	}
}

func (check *Checker) multipleSelectDefaults(list []*syntax.CommClause) {
	var first *syntax.CommClause
	for _, c := range list {
		if c.Comm == nil {
			if first != nil {
				check.errorf(c, DuplicateDefault, "multiple defaults (first at %s)", first.Pos())