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On 09/12/13 19:05, giucam (contact) wrote:<br>
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<div dir="ltr">Having said all that, I <i>strongly dislike</i> changing
libraries like this. I've been burned by this before, when the
Mercury team re-ordered some arguments to map.insert to be more
conducive to state variables, breaking hundreds of lines of
code. This change would be possibly worse, because it wouldn't
triggered any compiler errors, but may introduce subtle
performance issues into peoples' code that has already taken
into account the characteristics of this predicate.<br>
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I'd like to amplify Matt's comments on this. Changing argument
order in the standard library has been a constant irritation to me
and my students in Declarative Programming. Students do their work
on their own laptops, and then submit it to be assessed on centrally
maintained machines, and these tend to be different versions. It's
mystifying at first that the the code won't compile, and
unfortunately, the error messages are often not very helpful
locating the problem in such cases. OK, it's not unexpected to find
that code written with the latest library may not work with an older
library version, but the fact you can't drop back to using the old
version and expect it to work with both is not what one expects, and
it can be time consuming and frustrating to engineer code that will
work with multiple versions of the mercury library.<br>
<br>
<pre class="moz-signature" cols="72">--
Peter Schachte I suppose it is tempting, if the only tool
University of Melbourne you have is a hammer, to treat everything
<a class="moz-txt-link-abbreviated" href="mailto:schachte@unimelb.edu.au">schachte@unimelb.edu.au</a> as if it were a nail. -- Abraham Maslow
<a class="moz-txt-link-abbreviated" href="http://www.cs.mu.oz.au/~schachte/">www.cs.mu.oz.au/~schachte/</a>
Phone: +61 3 8344 1338
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