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Timeline for How is pattern specificity decided?

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Apr 13, 2017 at 12:55 history edited CommunityBot
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Jul 21, 2016 at 15:19 comment added masterxilo In V10, there is GeneralUtilities`PatternOrder, which is based on Internal`ComparePatterns. The definition is available (after loading "GeneralUtilities`"). It may be worth exploring. (It does not seem to do the same as my PatternOrder below).
Jul 21, 2016 at 15:12 answer added masterxilo timeline score: 3
Feb 10, 2016 at 19:34 history edited Mr.Wizard
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Feb 10, 2016 at 15:12 review Close votes
Feb 10, 2016 at 19:34
Dec 2, 2014 at 9:10 answer added Stuart Poss timeline score: 4
Dec 1, 2014 at 18:55 answer added Stuart Poss timeline score: 1
Dec 26, 2013 at 6:08 comment added carlosayam Pattern specificity reminds me of en.m.wikipedia.org/wiki/Unification_(computer_science)
Jul 23, 2012 at 19:05 comment added Kim Morrison @Szabolcs, maybe it's better to say that I'm still thinking about it.
Jul 23, 2012 at 19:05 comment added Kim Morrison @magma, when you take into account the time order in which the rules are attached to a symbol, you can obtain a total ordering (as I mentioned in the question). It's pretty easy to see, by playing around with examples that the functions I show above appear to define a partial ordering.
Jul 23, 2012 at 19:02 comment added Kim Morrison @Mr. Wizard, Internal`ComparePatterns says that __ and (_).. are each more specific than the other, while my 'experimental' approach above says they are incomparable.
Jul 23, 2012 at 10:37 history tweeted twitter.com/#!/StackMma/status/227351840499585024
Jul 23, 2012 at 9:07 comment added magma Is it really a partial order? I would argue that it is a total order, since MMA always orders patterns in some way. If it cannot determine algorithmic specificity, it uses temporal or lexicographic ordering (I think), which is another kind of specificity, after all.
Jul 23, 2012 at 8:13 comment added Szabolcs This question made me wonder, are you still working on omath?
Jul 23, 2012 at 8:13 comment added Mr.Wizard This is a deep question. As a point of interest, are you aware of an example where Internal`ComparePatterns fails to distinguish patterns in the way that your test functions do? In other words is it plausible that this function or the mechanism behind it in fact is used?
Jul 23, 2012 at 7:46 history asked Kim Morrison CC BY-SA 3.0