<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;">Subtle stuff.<br><br>Thanks, everyone, for your patience. You've been VERY helpful. Great list!<br><br>Michael<br><br>--- On <b>Sat, 7/31/10, Brandon S Allbery KF8NH <i><allbery@ece.cmu.edu></i></b> wrote:<br><blockquote style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;"><br>From: Brandon S Allbery KF8NH <allbery@ece.cmu.edu><br>Subject: Re: [Haskell-cafe] Laziness question<br>To: haskell-cafe@haskell.org<br>Date: Saturday, July 31, 2010, 2:29 PM<br><br><div class="plainMail">-----BEGIN PGP SIGNED MESSAGE-----<br>Hash: SHA1<br><br>On 7/31/10 14:24 , michael rice wrote:<br>> Are you saying:<br>> <br>> [ head x ] -> [ *thunk* ] and length [ *thunk* ] -> 1, independent of<br>> what *thunk* is, even head [], i.e., *thunk* never needs be
evaluated?<br><br>Exactly. (I was being cagey because the first response was cagey, possibly<br>suspecting a homework question although it seems like an odd time for it.)<br><br>length not only does not look inside of the thunk, it *can't* look inside<br>it; all it knows is that it has a list, it specifically does *not* know what<br>that list can hold. So the only thing it can do is count the number of<br>"unknown somethings" in the list.<br><br>- -- <br>brandon s. allbery [linux,solaris,freebsd,perl] <a ymailto="mailto:allbery@kf8nh.com" href="/mc/compose?to=allbery@kf8nh.com">allbery@kf8nh.com</a><br>system administrator [openafs,heimdal,too many hats] <a ymailto="mailto:allbery@ece.cmu.edu" href="/mc/compose?to=allbery@ece.cmu.edu">allbery@ece.cmu.edu</a><br>electrical and computer engineering, carnegie mellon university KF8NH<br>-----BEGIN PGP
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