return
			} else if next == ')' {
				rparen := in.lex()
				if in.peek().isEOL() {
					// Empty block.
					in.lex()
					in.file.Stmt = append(in.file.Stmt, &LineBlock{
						Start:  start,
						Token:  tokens,
						LParen: LParen{Pos: tok.pos},
						RParen: RParen{Pos: rparen.pos},
					})
					return
				}
				// '( )' in the middle of the line, not a block.

		Rparen token.Pos // position of ")"
	}

	// A CallExpr node represents an expression followed by an argument list.
	CallExpr struct {
		Fun      Expr      // function expression
		Lparen   token.Pos // position of "("
		Args     []Expr    // function arguments; or nil
		Ellipsis token.Pos // position of "..." (token.NoPos if there is no "...")
		Rparen   token.Pos // position of ")"
	}

						pos := n.Args[0].Pos()
						fun := &ast.SelectorExpr{X: newIdent(pos, "posn"), Sel: newIdent(pos, "Pos")}
						arg := &ast.CallExpr{Fun: fun, Lparen: pos, Args: nil, Ellipsis: token.NoPos, Rparen: pos}
						n.Args[0] = arg
						return false
					}
				case "addf":
					// rewrite err.addf(pos, ...) to err.addf(posn, ...)
					if isIdent(n.Args[0], "pos") {
						pos := n.Args[0].Pos()

				comments = append(comments, d.Doc)
			}
		}
	}

	// Synthesize import declaration.
	importDecl := &ast.GenDecl{
		Tok:    token.IMPORT,
		Lparen: 1, // Need non-zero Lparen and Rparen so that printer
		Rparen: 1, // treats this as a factored import.
	}
	importDecl.Specs = append(namedImports, blankImports...)

	// Synthesize main function.
	funcDecl := &ast.FuncDecl{
		Name: ast.NewIdent("main"),

		check.nonGeneric(nil, x)
		if x.mode == invalid {
			return conversion
		}
		T := x.typ
		x.mode = invalid
		switch n := len(call.Args); n {
		case 0:
			check.errorf(inNode(call, call.Rparen), WrongArgCount, "missing argument in conversion to %s", T)
		case 1:
			check.expr(nil, x, call.Args[0])
			if x.mode != invalid {
				if hasDots(call) {

		"{{/*}}",
		hasError, `comment1:1: unclosed comment`},
	{"comment2",
		"{{/*\nhello\n}}",
		hasError, `comment2:1: unclosed comment`},
	{"lparen",
		"{{.X (1 2 3}}",
		hasError, `unclosed left paren`},
	{"rparen",
		"{{.X 1 2 3 ) }}",
		hasError, "unexpected right paren"},
	{"rparen2",
		"{{(.X 1 2 3",
		hasError, `unclosed action`},
	{"space",
		"{{`x`3}}",
		hasError, `in operand`},
	{"idchar",