Jira (PUP-1172) Several bits of the language are order dependant

[Henrik Lindberg (JIRA)]

Title: Message Title

Henrik Lindberg commented on an issue   Re: Several bits of the language are order dependant The language is actually very much evaluation order dependent, has always been, and probably will be in the future. If the language is to become completely order independent, we are really talking about a new completely function oriented language. At the same time, the created catalog is a declarative thing that is compiled by the language, here order is defined by other mechanisms. If the language is to become truly order independent, then this would work: $a = $b $b = 10 The implications of that is that we have a completely different language that pretty much breaks all existing code. If we instead take the opposite approach and take an approach with Futures - i.e. that parts that are lazily evaluated return a future, then we also have to introduce threading, as you can't block on the future otherwise. IMO that is taking a large step away from the language being a DSL for catalogs and it introduces concepts that even computer science people in average have issues dealing with correctly. What is going on with the language though is a gradual cleanup of hard to understand (odd/weird) behavior and deprecation/removal of the corner cases that lead to most of the problems with evaluation order. New features in the language will later allow giving lambdas/closures to lazily evaluated logic to ensure that something runs after the construct it is attached to (real closures can not yet be implemented, as they require further refactoring of the puppet core (mainly how scope works). This is something we may get around to in Puppet 5. As an example, there is not much you can do with a collector (except realize and override attributes of resources), if you can pass a lambda it can be called once the collector has been fully evaluated. Another goal is to break up puppet into smaller pieces with well defined APIs. With this in place, it is much easier to to experiment with new languages, or even using existing languages and APIs to compile catalogs. So... what to do with this issue - it is basically a very extensive wish for a different language. At the same time the issue of strange order wrt. what is defined at any given moment. My suggestion is to file concrete tickets for concrete things that are not working as expected - many such cases have been fixed since the original issue was filed in redmine, and other are also logged and being worked on. There will be major changes coming in Puppet 4 with an overhaul of the chain "from puppet source to entries in the catalog", and more things to come in Puppet 5. With that long note, I am going to be bold and mark this issue as "won't fix". Add Comment   Puppet / PUP-1172 Several bits of the language are order dependant I am filing this as a bug, could be a feature request too? anyway, puppet is pointedly a order independent language this is a major tenant of how things work and how manifests gets constructed, nodes populated and so forth - this is probably a discussion on its own but thats my view. Assuming we agree its all independent of order then functions like... This message was sent by Atlassian JIRA (v6.1.4#6159-sha1:44eaede) -- You received this message because you are subscribed to the Google Groups "Puppet Bugs" group. To unsubscribe from this group and stop receiving emails from it, send an email to puppet-bugs+unsubscr...@googlegroups.com. To post to this group, send email to puppet-bugs@googlegroups.com. Visit this group at http://groups.google.com/group/puppet-bugs. For more options, visit https://groups.google.com/groups/opt_out.