content: -- Notices:
  --
  -- Copyright 2020 United States Government as represented by the Administrator of the National Aeronautics and Space Administration. All Rights Reserved.
  
  -- Disclaimers
  -- No Warranty: THE SUBJECT SOFTWARE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY OF ANY KIND, EITHER EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, ANY WARRANTY THAT THE SUBJECT SOFTWARE WILL CONFORM TO SPECIFICATIONS, ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR FREEDOM FROM INFRINGEMENT, ANY WARRANTY THAT THE SUBJECT SOFTWARE WILL BE ERROR FREE, OR ANY WARRANTY THAT DOCUMENTATION, IF PROVIDED, WILL CONFORM TO THE SUBJECT SOFTWARE. THIS AGREEMENT DOES NOT, IN ANY MANNER, CONSTITUTE AN ENDORSEMENT BY GOVERNMENT AGENCY OR ANY PRIOR RECIPIENT OF ANY RESULTS, RESULTING DESIGNS, HARDWARE, SOFTWARE PRODUCTS OR ANY OTHER APPLICATIONS RESULTING FROM USE OF THE SUBJECT SOFTWARE.  FURTHER, GOVERNMENT AGENCY DISCLAIMS ALL WARRANTIES AND LIABILITIES REGARDING THIRD-PARTY SOFTWARE, IF PRESENT IN THE ORIGINAL SOFTWARE, AND DISTRIBUTES IT "AS IS."
  
  -- Waiver and Indemnity:  RECIPIENT AGREES TO WAIVE ANY AND ALL CLAIMS AGAINST THE UNITED STATES GOVERNMENT, ITS CONTRACTORS AND SUBCONTRACTORS, AS WELL AS ANY PRIOR RECIPIENT.  IF RECIPIENT'S USE OF THE SUBJECT SOFTWARE RESULTS IN ANY LIABILITIES, DEMANDS, DAMAGES, EXPENSES OR LOSSES ARISING FROM SUCH USE, INCLUDING ANY DAMAGES FROM PRODUCTS BASED ON, OR RESULTING FROM, RECIPIENT'S USE OF THE SUBJECT SOFTWARE, RECIPIENT SHALL INDEMNIFY AND HOLD HARMLESS THE UNITED STATES GOVERNMENT, ITS CONTRACTORS AND SUBCONTRACTORS, AS WELL AS ANY PRIOR RECIPIENT, TO THE EXTENT PERMITTED BY LAW.  RECIPIENT'S SOLE REMEDY FOR ANY SUCH MATTER SHALL BE THE IMMEDIATE, UNILATERAL TERMINATION OF THIS AGREEMENT.
  
  
  module AbsSpecLang where
  
  import Text.Printf
  import PPExt
  import Prelude hiding ((<>))
  import Data.Scientific
  import AbsPVSLang (ResultField(..), PVSType(..))
  
  data LBound
      = LBInt Integer
      | LBDouble Rational
      | LInf
    deriving (Eq, Ord, Show, Read)
  
  data UBound
      = UBInt Integer
      | UBDouble Rational
      | UInf
    deriving (Eq, Ord, Show, Read)
  
  data VarBind
    = VarBind String ResultField PVSType LBound UBound
    deriving (Eq, Ord, Show, Read)
  
  data SpecBind = SpecBind String [VarBind]
    deriving (Eq, Ord, Show, Read)
  
  newtype Spec = Spec [SpecBind]
    deriving (Eq, Ord, Show, Read)
  
  emptySpec :: Spec
  emptySpec = Spec []
  
  findInSpec :: String -> [SpecBind] -> Maybe [VarBind]
  findInSpec _ [] = Nothing
  findInSpec fun (SpecBind g varBind : rest) | fun == g = Just varBind
                                             | otherwise = findInSpec fun rest
  
  
  -----------------------
  -- PPExt instances --
  -----------------------
  
  instance PPExt LBound where
    prettyDoc (LBInt i) = integer i
    prettyDoc (LBDouble d) = text $ printf ("%."++ show e ++"f") (fromRational d :: Double)
       where
        e = abs $ base10Exponent $ fromFloatDigits (fromRational d :: Double)
    prettyDoc LInf = text "-inf"
  
  
  instance PPExt UBound where
    prettyDoc (UBInt i) = integer i
    prettyDoc (UBDouble d) = text $ printf ("%."++ show e ++"f") (fromRational d :: Double)
       where
        e = abs $ base10Exponent $ fromFloatDigits (fromRational d :: Double)
    prettyDoc UInf = text "+inf"
  
  
  instance PPExt VarBind where
    prettyDoc (VarBind x ResValue _ lb ub)
      = text x <+> text "in" <+> lbrack <> prettyDoc lb <> comma <+> prettyDoc ub <> rbrack
    prettyDoc (VarBind x (ResRecordField field) _ lb ub)
      = text x <> text "`" <> text field <+> text "in" <+> lbrack <> prettyDoc lb <> comma <+> prettyDoc ub <> rbrack
    prettyDoc (VarBind x (ResTupleIndex idx) _ lb ub)
      = text x <> text "`" <> integer idx  <+> text "in" <+> lbrack <> prettyDoc lb <> comma <+> prettyDoc ub <> rbrack
  
  
  instance PPExt SpecBind where
    prettyDoc (SpecBind f vbs) = text f <+> colon
                                 <+> hsep (punctuate comma $ map prettyDoc vbs)
  
  
  instance PPExt Spec where
    prettyDoc (Spec specs) = vcat $ punctuate (text ".") $ map prettyDoc specs
  
  