{- |

Module : $Header$

Description : abstract syntax for Relational Schemes

Copyright : Dominik Luecke, Uni Bremen 2008

License : similar to LGPL, see Hets/LICENSE.txt or LIZENZ.txt

Maintainer : luecke@informatik.uni-bremen.de

Stability : provisional

Portability : portable

Abstract syntax for Relational Schemes

-}

module RelationalScheme.AS

(

RSRelType(..)

, RSQualId(..)

, RSRel(..)

, RSRelationships(..)

, RSScheme(..)

, Sentence

)

where

import Common.Id

import Common.AS_Annotation

import Common.Doc

import Common.DocUtils

import RelationalScheme.Keywords

import RelationalScheme.Sign

-- DrIFT command

{-! global: UpPos !-}

data RSRelType = RSone_to_one | RSone_to_many | RSmany_to_one | RSmany_to_many

deriving (Eq, Ord, Show)

-- first Id is TableId, second is columnId

data RSQualId = RSQualId Id Id Range

deriving (Eq, Ord)

data RSRel = RSRel [RSQualId] [RSQualId] RSRelType Range

deriving (Eq, Ord)

data RSRelationships = RSRelationships [Annoted RSRel] Range

deriving (Eq, Ord)

data RSScheme = RSScheme RSTables RSRelationships Range

deriving (Eq, Ord)

type Sentence = RSRel

-- Pretty printing stuff

instance Show RSScheme where

show s = case s of

RSScheme t r _ -> (show t) ++ "\n" ++ (show r)

instance Show RSRelationships where

show r = case r of

RSRelationships r1 _ ->

case r1 of

[] -> ""

_ -> rsRelationships ++ "\n" ++

(unlines $ map (show . item) r1)

instance Show RSRel where

show r = case r of

RSRel i1 i2 tp _ -> (concatComma $ map show i1) ++ " " ++ rsArrow ++ " "++

(concatComma $ map show i2) ++ " " ++ show tp

instance Show RSQualId where

show q = case q of

RSQualId i1 i2 _ -> (show i1) ++ "." ++ (show i2)

instance Pretty RSScheme where

pretty = text . show

instance Pretty RSRel where

pretty = text . show