cvs commit: fptools/libraries/base/Data/Array Base.hs

[Simon Marlow]

simonmar    2003/01/13 03:42:17 PST

  Modified files:
    libraries/base/Data/Array Base.hs 
  Log:
  UArrays should always be initialized with known elements, otherwise we
  can lose referential transparency:
  
  Prelude> :m + Data.Array.Unboxed
  Prelude Data.Array.Unboxed> let f () = array (1, 5) [] :: UArray Int Int
  Prelude Data.Array.Unboxed> f () == f ()
  False
  
  Noticed-by: Tomasz Zielonka <t.zielonka@students.mimuw.edu.pl>
  
  MERGE TO STABLE
  
  Revision  Changes    Path
  1.14      +24 -21    fptools/libraries/base/Data/Array/Base.hs