<HTML dir=ltr><HEAD><TITLE>[clean-list] Simplified uniqueness typing</TITLE>
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<DIV dir=ltr><FONT face=Arial color=#000000 size=2>Hi Jari-Matti,</FONT></DIV>
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<DIV dir=ltr><FONT face=Arial color=#000000 size=2>Rinus Plasmeijer told me a while ago that they first want to test/reason extensively whether there are any programs accepted by the existing uniqueness type checker but not by the new one. Also, the new system requires somewhat different uniqueness annotations, so there would be a need to have existing clean software automatically converted. Neither are easy tasks.</FONT></DIV>
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<DIV dir=ltr><FONT face=Arial size=2>Clean already has modest ways to split off many unique objects off of one 'mother' object and at the end recombine them: You can open many unique files based on one unique file system. This is easily implemented because there is only one filesystem: whenever you close a unique file, you can be sure that it is closed into the right filesystem.</FONT></DIV>
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<DIV dir=ltr><FONT face=Arial size=2>But this is not a general feature that you could for instance apply to a unique array. A difficulty is that when 'closing' a part of the unique array split off earlier, you should close it into the same mother-array. There is no static test the compiler can apply to ensure this. Also, in case of an array, when you split off unique sub-arrays, they should be non overlapping. The compiler cannot test this in general.</FONT></DIV>
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<DIV dir=ltr><FONT face=Arial size=2>I expect that for parallel processing there will be a number of special purpose constructs like opening and closing files. I know of no research in this direction.</FONT></DIV>
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<DIV dir=ltr><FONT face=Arial size=2>Regards Erik Zuurbier</FONT></DIV></DIV>
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<FONT face=Tahoma size=2><B>Van:</B> clean-list-bounces@science.ru.nl namens Jari-Matti Mäkelä<BR><B>Verzonden:</B> do 20-11-2008 12:12<BR><B>Aan:</B> clean-list@science.ru.nl<BR><B>Onderwerp:</B> [clean-list] Simplified uniqueness typing<BR></FONT><BR></DIV>
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<P><FONT size=2>Hi<BR><BR>are there any plans to adopt the simplified uniqueness typing system<BR>(<A href="http://www.cs.tcd.ie/~devriese/pub/ifl07-paper.pdf">http://www.cs.tcd.ie/~devriese/pub/ifl07-paper.pdf</A>) in the coming versions of<BR>Clean?<BR><BR>Another question - if Clean continues to support parallel/concurrent<BR>programming some day, does uniqueness typing support dividing a massive<BR>computational task to several threads and then combining the results or does<BR>it disallow this. Are there alternative approaches to this problem?<BR><BR>_______________________________________________<BR>clean-list mailing list<BR>clean-list@science.ru.nl<BR><A href="http://mailman.science.ru.nl/mailman/listinfo/clean-list">http://mailman.science.ru.nl/mailman/listinfo/clean-list</A><BR></FONT></P></DIV></BODY></HTML>