[GHC] #10930: missing empty-Enumeration and out-of-range warning for `Natural` (was: missing empty-Enumeration warning for `Natural`)

[GHC]

#10930: missing empty-Enumeration and out-of-range warning for `Natural`
-------------------------------------+-------------------------------------
        Reporter:  hvr               |                Owner:  hvr
            Type:  bug               |               Status:  new
        Priority:  low               |            Milestone:  8.0.1
       Component:  Compiler          |              Version:  7.10.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #7881, #10929     |  Differential Rev(s):  Phab:D1306
-------------------------------------+-------------------------------------
Description changed by hvr:

Old description:



New description:

 {{{
 GHCi, version 7.10.2: http://www.haskell.org/ghc/  :? for help
 λ:2> :set -XNegativeLiterals
 λ:3> (-123) :: Word

 <interactive>:3:2: Warning: Literal -123 is out of the Word range
 0..18446744073709551615
 18446744073709551493
 it :: Word

 λ:4> (-123) :: Numeric.Natural.Natural
 *** Exception: arithmetic underflow

 λ:5>
 λ:6> [10..3] :: [Word]
 <interactive>:6:1: Warning: Enumeration is empty
 []
 it :: [Word]

 λ:7> [10..3] :: [Numeric.Natural.Natural]
 []
 it :: [GHC.Natural.Natural]

 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10930#comment:2>
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