{- |

Module :$Header$

Copyright : uni-bremen and Razvan Pascanu

Licence : similar to LGPL, see HetCATS/LICENSE.txt or LIZENZ.txt

Maintainer : r.pascanu@iu-bremen.de

Stability : provisional

Portability : portable

Usefull function used by the parser.

TODO

- add comment.

-}

module PGIP.Common where

import PGIP.Commands

import Proofs.EdgeUtils

-- | The 'addOrReplace' function,given a CmdInterpeterStatus and a list of such CmdInterpeterStatus, replaces any occurance of that type

-- of CmdInterpeterStatus with the given one, and if none found it adds one to the list

addOrReplace::(CmdInterpreterStatus,[CmdInterpreterStatus])->[CmdInterpreterStatus]

addOrReplace (val,status)

= case val of

[] -> status

(Env x y):l -> case status of

[] -> addOrReplace(l,(Env x y):[])

CmdInitialState:ls -> addOrReplace ((Env x y):l,ls)

(OutputErr xx):_ -> (OutputErr xx):[]

(Env _ _):ls -> addOrReplace(l,(Env x y):ls)

(SelectedNodes xx):ls -> addOrReplace(l, (SelectedNodes xx):addOrReplace([Env x y],ls))

(SelectedNodes x):l -> case status of

[] -> addOrReplace (l,(SelectedNodes x):[])

CmdInitialState:ls -> addOrReplace ((SelectedNodes x):l, ls)

(OutputErr xx):_ -> (OutputErr xx):[]

(Env xx yy):ls -> addOrReplace(l, (Env xx yy):addOrReplace([SelectedNodes x], ls))

(SelectedNodes _):ls -> addOrReplace(l, (SelectedNodes x):ls)

OutputErr x -> (OutputErr x):[]

CmdInitialState -> status

-- | The 'extractFrom' function, given a list of CmdInterpeterStatus and a CmdInterpreterStatusID, it returns the first occurance of

-- that type of CmdInterpreterStatus from the list

extractFrom::([CmdInterpreterStatus],CmdInterpreterStatusID) -> Maybe CmdInterpreterStatus

extractFrom (status,cmdID)

= case cmdID of

EnvID -> do

case status of

[] -> Nothing

(Env x y):_ -> Just (Env x y)

_:ls-> (extractFrom (ls,cmdID))

-- | The 'extractNodeGoals' function, given a list of parsed goals extracts the NodeGoals as a list of LIB_ID's

--extractNodeGoals::[GOAL] -> [Id]

--extractNodeGoals ls

-- = case ls of

-- [] -> []

-- (Node x):l -> x:(extractNodeGoals l)

-- _:l -> extractNode l