<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><br></div><div>Take the parens out: </div><div><br></div><div><div>#lang racket</div><div>(class object% (super-new) (displayln "hello world") (field (x 10)) (displayln x))</div></div><div><br></div><br><div><div>On Dec 19, 2012, at 10:43 PM, Chen Xiao wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>class: field element is not an optionally renamed identifier-expression pair</div><div>  at: ((x 10))</div><div>  in: (class object% (super-new) (displayln "hello world") (field ((x 10))) (displayln x))</div> <br><div class="gmail_quote">2012/12/20 Matthias Felleisen <span dir="ltr"><<a href="mailto:matthias@ccs.neu.edu" target="_blank">matthias@ccs.neu.edu</a>></span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> (new (class object% (super-new) (displayln "hello world") (field ([x 10])) (displayln x)))</blockquote></div><br> </blockquote></div><br></body></html>