[GHC] #8370: Ranked Instances

[GHC]

#8370: Ranked Instances
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        Reporter:  wvv               |            Owner:
            Type:  feature request   |           Status:  closed
        Priority:  normal            |        Milestone:
       Component:  Compiler          |          Version:  7.6.3
      Resolution:  invalid           |         Keywords:
Operating System:  Unknown/Multiple  |     Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown      |       Difficulty:  Unknown
       Test Case:                    |       Blocked By:
        Blocking:                    |  Related Tickets:
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Changes (by carter):

 * status:  new => closed
 * resolution:   => invalid


Comment:

 Hey wvv.  Emailing cafe and getting no feedback is not sufficient reason
 to add a type system feature to ghc.

 As a rule, lack of feedback on an idea is a red flag rather than a go
 ahead.

 Remember the criterion I laid out for what most type system extensions
 need to satisfy to be suitable for consideration for ghc? It has to allow
 more valid programs and or prevent more bugs.

 You have given lots of syntactic examples without any clear explanation of
 the type system ideas or why anyone should care.

 Perhaps most importantly, your examples are hard to understand.  Adding
 type system features that are hard to understand for ghc devs, that
 requires even more care!

 Please, read some text books on type systems and programming languages, eg
 the one by Robert Harper is excellent, opinionated, and free online.

 We all really appreciate your enthusiasm, but please take the time to
 learn a solid type theory foundation first!  It's a lot of work, but it's
 also incredibly rewarding and you'll find it will really help force you to
 better clarify your ideas.

 Nb: working through even that one book will take a few months of work.  So
 any new proposals from you till after February 2014, at the earliest, I
 will probably be forced to close. And I will not explain as clearly as I
 have this time and the previous.  This is your last polite warning.

 If you wish to have any future seed of credibility with ghc devs, please
 take the time to learn and develop a more robust pl background wrt type
 systems before you  post another such proposal.

 Additionally: every serious type system proposal tends to be implemented
 by their advocate. You currently glaringly lack a clear picture of how
 type classes and constraint solving interact with inference work.  I
 strongly recommend you read the "outside in" paper to learn more of what's
 going on there


 Best of luck in your learning adventure!

 All the reading suggestions I mention are easy to google for, you should
 be able to find them on your own

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8370#comment:1>
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