<br><br><div class="gmail_quote">On Sat, May 30, 2009 at 10:32 PM, Cetin Sert <span dir="ltr"><<a href="mailto:cetin.sert@gmail.com">cetin.sert@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<span style="font-family:courier new,monospace"><span style="font-family:arial,helvetica,sans-serif">Thank you for your reply, I'd come up with the following:</span><br><br></span><div style="margin-left:40px"><div class="im">
<span style="font-family:courier new,monospace">timed :: Int → IO a → b → IO (Either b a)</span><br style="font-family:courier new,monospace">
<span style="font-family:courier new,monospace">timed max act def = do</span><br style="font-family:courier new,monospace"><br style="font-family:courier new,monospace"></div><span style="font-family:courier new,monospace"> r ← new</span><br style="font-family:courier new,monospace">
<span style="font-family:courier new,monospace"> </span><br style="font-family:courier new,monospace"><span style="font-family:courier new,monospace"> t ← forkIO $ do</span><br style="font-family:courier new,monospace">
<span style="font-family:courier new,monospace"> a ← act</span><br style="font-family:courier new,monospace"><span style="font-family:courier new,monospace"> r ≔ Right a</span><br style="font-family:courier new,monospace">
<br style="font-family:courier new,monospace"><span style="font-family:courier new,monospace"> s ← forkIO $ do</span><br style="font-family:courier new,monospace"><span style="font-family:courier new,monospace"> wait max</span><br style="font-family:courier new,monospace">
<span style="font-family:courier new,monospace"> e ← em r</span><br style="font-family:courier new,monospace"><span style="font-family:courier new,monospace"> case e of</span><br style="font-family:courier new,monospace">
<span style="font-family:courier new,monospace"> True → do</span><br style="font-family:courier new,monospace"><span style="font-family:courier new,monospace"> kill t</span><br style="font-family:courier new,monospace">
<span style="font-family:courier new,monospace"> r ≔ Left def</span><br style="font-family:courier new,monospace"><br style="font-family:courier new,monospace"><span style="font-family:courier new,monospace"> False → return ()</span><br style="font-family:courier new,monospace">
<br style="font-family:courier new,monospace"><span style="font-family:courier new,monospace"> takeMVar r</span><br></div><br><div class="gmail_quote">---------------------<br><br><div style="margin-left:40px"><span style="font-family:courier new,monospace">*Network.Port.Scan> timed 500 (wait 50000 >> return 0) 'x'</span><br style="font-family:courier new,monospace">
<span style="font-family:courier new,monospace">Left 'x'</span><br style="font-family:courier new,monospace"><span style="font-family:courier new,monospace">*Network.Port.Scan> timed 500000 (wait 50000 >> return 0) 'x'</span><br style="font-family:courier new,monospace">
<span style="font-family:courier new,monospace">Right 0</span><br></div><br>---------------------<br>
<br>before reading your reply:<div class="im"><br><br><div style="font-family:courier new,monospace;margin-left:40px">timed timeout act fallback = do</div><div style="font-family:courier new,monospace;margin-left:40px"> res <- newEmptyMVar</div>
<div style="font-family:courier new,monospace;margin-left:40px"> tid <- forkIO $ act >>= writeMVar res</div><div style="font-family:courier new,monospace;margin-left:40px"> threadDelay timeout</div><div style="font-family:courier new,monospace;margin-left:40px">
stillRunning <- isEmptyMVar res</div>
<div style="font-family:courier new,monospace;margin-left:40px"> if stillRunning then killThread tid >> return fallback else takeMVar res</div><br></div>---------------------<br><br><div style="margin-left:40px">
<span style="font-family:courier new,monospace">*Network.Port.Scan> timed2 500 (wait 50000 >> return 0) 'x'</span><br style="font-family:courier new,monospace"><br style="font-family:courier new,monospace">
<span style="font-family:courier new,monospace"><interactive>:1:33:</span><br style="font-family:courier new,monospace"><span style="font-family:courier new,monospace"> No instance for (Num Char)</span><br style="font-family:courier new,monospace">
<span style="font-family:courier new,monospace"> arising from the literal `0' at <interactive>:1:33</span><br style="font-family:courier new,monospace"><span style="font-family:courier new,monospace"> Possible fix: add an instance declaration for (Num Char)</span><br style="font-family:courier new,monospace">
<span style="font-family:courier new,monospace"> In the first argument of `return', namely `0'</span><br style="font-family:courier new,monospace"><span style="font-family:courier new,monospace"> In the second argument of `(>>)', namely `return 0'</span><br style="font-family:courier new,monospace">
<span style="font-family:courier new,monospace"> In the second argument of `timed2', namely</span><br style="font-family:courier new,monospace"><span style="font-family:courier new,monospace"> `(wait 50000 >> return 0)'</span><br>
</div></div></blockquote><div><br></div><div><br></div><div>Right, I forgot about the "Either" bit so you'd have to make sure the action's result and the default has the same type (or modify it to return an Either).</div>
</div><br><br clear="all"><br>-- <br>Sebastian Sylvan<br>+44(0)7857-300802<br>UIN: 44640862<br>