{- |

Module : $Header$

Description : folding functions for CSL terms and commands

Copyright : (c) Ewaryst.Schulz, DFKI 2010

License : GPLv2 or higher, see LICENSE.txt

Maintainer : Ewaryst.Schulz@dfki.de

Stability : provisional

Portability : portable

folding functions for CSL terms and commands

-}

module CSL.Fold where

import Common.Id

import CSL.AS_BASIC_CSL

data Record a b c = Record

{ foldAss :: c -> CMD -> b -> b -> a

, foldCmd :: c -> CMD -> String -> [b] -> a

, foldSequence :: c -> CMD -> [a] -> a

, foldCond :: c -> CMD -> [(b, [a])] -> a

, foldRepeat :: c -> CMD -> b -> [a] -> a

, foldVar :: c -> EXPRESSION -> Token -> b

, foldOp :: c -> EXPRESSION -> String -> [EXTPARAM] -> [b] -> Range -> b

, foldList :: c -> EXPRESSION -> [b] -> Range -> b

, foldInterval :: c -> EXPRESSION -> APFloat -> APFloat -> Range -> b

, foldInt :: c -> EXPRESSION -> APInt -> Range -> b

, foldDouble :: c -> EXPRESSION -> APFloat -> Range -> b

}

-- | Produces an error with given message on all entries. Use this if you

-- overwrite only the EXPRESSION part and you do not use the CMD part anyway

-- , e.g., if you use the record in foldTerm

emptyRecord :: String -> Record a b c

emptyRecord s =

Record { foldAss = error s

, foldCmd = error s

, foldSequence = error s

, foldCond = error s

, foldRepeat = error s

, foldVar = error s

, foldOp = error s

, foldList = error s

, foldInterval = error s

, foldInt = error s

, foldDouble = error s

}

-- | The identity transformation

idRecord :: Record CMD EXPRESSION c

idRecord =

Record { foldAss = \ _ v _ _ -> v

, foldCmd = \ _ v _ _ -> v

, foldSequence = \ _ v _ -> v

, foldCond = \ _ v _ -> v

, foldRepeat = \ _ v _ _ -> v

, foldVar = \ _ v _ -> v

, foldOp = \ _ v _ _ _ _ -> v

, foldList = \ _ v _ _ -> v

, foldInterval = \ _ v _ _ _ -> v

, foldInt = \ _ v _ _ -> v

, foldDouble = \ _ v _ _ -> v

}

-- | Passes the transformation through the CMD part and is the identity

-- on the EXPRESSION part

passRecord :: Record CMD EXPRESSION c

passRecord =

Record { foldAss = \ _ _ -> Ass

, foldCmd = \ _ _ -> Cmd

, foldSequence = \ _ _ -> Sequence

, foldCond = \ _ _ -> Cond

, foldRepeat = \ _ _ -> Repeat

, foldVar = \ _ v _ -> v

, foldOp = \ _ v _ _ _ _ -> v

, foldList = \ _ v _ _ -> v

, foldInterval = \ _ v _ _ _ -> v

, foldInt = \ _ v _ _ -> v

, foldDouble = \ _ v _ _ -> v

}

-- | Returns the first constant on the CMD part and the second

-- on the EXPRESSION part

constRecord :: a -> b -> Record a b c

constRecord a b =

Record { foldAss = \ _ _ _ _ -> a

, foldCmd = \ _ _ _ _ -> a

, foldSequence = \ _ _ _ -> a

, foldCond = \ _ _ _ -> a

, foldRepeat = \ _ _ _ _ -> a

, foldVar = \ _ _ _ -> b

, foldOp = \ _ _ _ _ _ _ -> b

, foldList = \ _ _ _ _ -> b

, foldInterval = \ _ _ _ _ _ -> b

, foldInt = \ _ _ _ _ -> b

, foldDouble = \ _ _ _ _ -> b

}

foldCMD :: Record a b c -> c -> CMD -> a

foldCMD r acc f = case f of

Ass c def -> foldAss r acc f (foldTerm r acc c) $ foldTerm r acc def

Cmd s l -> foldCmd r acc f s $ map (foldTerm r acc) l

Sequence l -> foldSequence r acc f $ map (foldCMD r acc) l

Cond l -> foldCond r acc f $ map cf l where

cf (x, y) = (foldTerm r acc x, map (foldCMD r acc) y)

Repeat c l -> foldRepeat r acc f (foldTerm r acc c) $ map (foldCMD r acc) l

foldTerm :: Record a b c -> c -> EXPRESSION -> b

foldTerm r acc t = case t of

Var tok -> foldVar r acc t tok

Op s epl al rg -> foldOp r acc t s epl (map (foldTerm r acc) al) rg

List l rg -> foldList r acc t (map (foldTerm r acc) l) rg

Interval from to rg -> foldInterval r acc t from to rg

Int i rg -> foldInt r acc t i rg

Double f rg -> foldDouble r acc t f rg