[GHC] #16089: seq is not cooperating with :sprint in GHCi as expected

[GHC]

#16089: seq is not cooperating with :sprint in GHCi as expected
-------------------------------------+-------------------------------------
        Reporter:  radrow            |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  GHCi              |              Version:  8.6.3
      Resolution:                    |             Keywords:  seq sprint
                                     |  strictness
Operating System:  Linux             |         Architecture:
 Type of failure:  Incorrect result  |  Unknown/Multiple
  at runtime                         |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by osa1):

 I can't reproduce this:

 {{{
 GHCi, version 8.6.3: http://www.haskell.org/ghc/  :? for help
 Loaded GHCi configuration from /home/omer/rcbackup/.ghci
 λ:1> let x = [True, False]
 λ:2> :sprint x
 x = [True,False]
 }}}

 With 8.4.4:

 {{{
 GHCi, version 8.4.4: http://www.haskell.org/ghc/  :? for help
 Loaded GHCi configuration from /home/omer/rcbackup/.ghci
 λ:1> let x = [True, False]
 λ:2> :sprint x
 x = [True,False]
 }}}

 With 8.2.2:

 {{{
 GHCi, version 8.2.2: http://www.haskell.org/ghc/  :? for help
 Loaded GHCi configuration from /home/omer/rcbackup/.ghci
 λ:1> let x = [True, False]
 λ:2> :sprint x
 x = [True,False]
 }}}

 However if I use a list that is not completely static then I can see that
 `:sprint` doesn't print the evaluated constructor:

 {{{
 GHCi, version 8.6.3: http://www.haskell.org/ghc/  :? for help
 Loaded GHCi configuration from /home/omer/rcbackup/.ghci
 λ:1> let x = [1..]
 λ:2> :sprint x
 x = _
 λ:3> x `seq` ()
 ()
 λ:4> :sprint x
 x = _
 }}}

 Even `:print` doesn't work as expected (I'd expect it to print something
 like `x : y`):

 {{{
 λ:5> :print x
 x = (_t1::(Num a, Enum a) => [a])
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16089#comment:1>
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