Check out Hoogle: <a href="http://haskell.org/hoogle/?q=guard">http://haskell.org/hoogle/?q=guard</a><br><br>import Control.Monad<br><br>-Greg<br><br><br><br><div><span class="gmail_quote">On 2/12/07, <b class="gmail_sendername">
<a href="mailto:phiroc@free.fr">phiroc@free.fr</a></b> <<a href="mailto:phiroc@free.fr">phiroc@free.fr</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Hello,<br><br>the "Advanced Monads" page in the Haskell Wikibook<br>(<a href="http://en.wikibooks.org/wiki/Haskell/Advanced_monads">http://en.wikibooks.org/wiki/Haskell/Advanced_monads</a>) contains the following
<br>example of a List Monad<br><br>pythags = do<br> x <- [1..]<br> y <- [x..]<br> z <- [y..]<br> guard (x^2 + y^2 == z^2)<br> return (x, y, z)<br><br>However, whenever you load that function definition into Hugs or GHCi, you get a
<br>message saying that "guard" is an undefined variable.<br><br>Does anyone know why?<br><br>Thanks.<br><br>phiroc<br>_______________________________________________<br>Haskell-Cafe mailing list<br><a href="mailto:Haskell-Cafe@haskell.org">
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