On 18 August 2011 19:27, Mark Proctor <mproc...@codehaus.org> wrote: > On 18/08/2011 18:17, Wolfgang Laun wrote: > > On 18 August 2011 18:38, Mark Proctor <mproc...@codehaus.org> wrote: > >> We are looking to tighten up accumulate, using a new keyword to >> differentiate. It will use ; for separation, to follow a similar form to >> a 'for' loop. >> >> acc( CE*; >> <func>*; >> <guard>? ) >> >> so something like: >> >> acc( $o : Order(); >> $min : min( $o.value ), >> $max : max($o.value); >> $min > 100 && $max < 100 ) >> > > Given that I can do this today using an eval after the accumulate CE: > What's the big gain, as compared to the nuisance of yet another CE, with the > need to document (which, traditionally, isn't done so eagerly) and teach and > learn and getting it free of bugs? > > I find the above looks cleaner and easier to read, the more we can reduce > the need for 'eval' the better. It is a common enough use case that I feel > it is worth support. >
Well, a condition that's never true isn't a good use case. Even after repairing it, the example does not tell you *where *the min and max, respectively, are. Apart from determining the exact value of mininimum and maximum (which could easily be added, together with locating the containing Order!) not Order( value <= 100 ) not Order( value >= 200 ) is more descriptive that the rather procedural "for" hidden in the proposed "acc". Perhaps there are better use case; this one does not convince me. -W > Acc is used a lot for CEP use cases and we need a syntax that can compete > succinctly with alternative approaches - if we look like a dog dinner, we'll > lose out to alternative CEP syntaxes. The separation of the segments using > ";" gives a clearer distinction too, and it's 'for' loop like nature should > more natural to people new to the engine. > > Mark > > > -W > > >> >> I have wondered if we could use pipes on our functions, to be able to >> pass the results of one function into another - just not sure how that >> will work or look yet. >> func(...) in func(...) >> func(...) | func(...) >> >> Mark >> >> _______________________________________________ >> rules-dev mailing list >> rules-dev@lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/rules-dev >> > > > > _______________________________________________ > rules-dev mailing > listrules-dev@lists.jboss.orghttps://lists.jboss.org/mailman/listinfo/rules-dev > > > > _______________________________________________ > rules-dev mailing list > rules-dev@lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-dev > >
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