{- |

Module : $Header$

Description : abstract syntax for Relational Schemes

Copyright : Dominik Luecke, Uni Bremen 2008

License : GPLv2 or higher, see 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

, map_rel

, getRels

, getSignature

)

where

import Common.Id

import Common.AS_Annotation

import Common.Doc

import Common.DocUtils

import RelationalScheme.Keywords

import RelationalScheme.Sign

import qualified Data.Map as Map

import Common.Result

-- DrIFT command

{-! global: GetRange !-}

data RSRelType = RSone_to_one | RSone_to_many | RSmany_to_one | RSmany_to_many

deriving (Eq, Ord)

-- first Id is TableId, second is columnId

data RSQualId = RSQualId

{

table :: Id

, column :: Id

, q_pos :: Range

}

deriving (Eq, Ord, Show)

data RSRel = RSRel

{

r_lhs :: [RSQualId]

, r_rhs :: [RSQualId]

, r_type :: RSRelType

, r_pos :: Range

}

deriving (Eq, Ord, Show)

data RSRelationships = RSRelationships [Annoted RSRel] Range

deriving (Eq, Ord, Show)

data RSScheme = RSScheme RSTables RSRelationships Range

deriving (Eq, Ord, Show)

type Sentence = RSRel

-- Pretty printing stuff

instance Pretty RSScheme where

pretty (RSScheme t r _) = pretty t $++$ pretty r

instance Pretty RSRelationships where

pretty (RSRelationships rs _) = if null rs then empty else

keyword rsRelationships $+$ vcat (map pretty rs)

instance Pretty RSRel where

pretty (RSRel i1 i2 tp _) =

let tbl is = case is of

[] -> empty

t : _ -> pretty (table t)

<> brackets (ppWithCommas is)

in fsep [tbl i1, funArrow, tbl i2, keyword (show tp)]

instance Pretty RSQualId where

pretty = pretty . column

instance Show RSRelType where

show r = case r of

RSone_to_one -> rs1to1

RSone_to_many -> rs1tom

RSmany_to_one -> rsmto1

RSmany_to_many -> rsmtom

map_qualId :: RSMorphism -> RSQualId -> Result RSQualId

map_qualId mor qid =

let

(tid, rid, rn) = case qid of

RSQualId i1 i2 rn1 -> (i1, i2, rn1)

in maybe (fail "map_qualId") return $ do

mtid <- Map.lookup tid $ table_map mor

rmor <- Map.lookup tid $ column_map mor

mrid <- Map.lookup rid $ col_map rmor

return $ RSQualId mtid mrid rn

map_rel :: RSMorphism -> RSRel -> Result RSRel

map_rel mor rel =

let

(q1, q2, rt, rn) = case rel of

RSRel qe1 qe2 rte rne -> (qe1, qe2, rte, rne)

in

do

mq1 <- mapM (map_qualId mor) q1

mq2 <- mapM (map_qualId mor) q2

return $ RSRel mq1 mq2 rt rn

{-

map_arel :: RSMorphism -> (Annoted RSRel) -> Result (Annoted RSRel)

map_arel mor arel =

let

rel = item arel

(q1, q2, rt, rn) = case rel of

RSRel qe1 qe2 rte rne -> (qe1, qe2, rte, rne)

in

do

mq1 <- mapM (map_qualId mor) q1

mq2 <- mapM (map_qualId mor) q2

return $ arel

{

item = RSRel mq1 mq2 rt rn

}

map_relships :: RSMorphism -> RSRelationships -> Result RSRelationships

map_relships mor rsh =

let

(arel, rn) = case rsh of

RSRelationships arel1 rn1 -> (arel1, rn1)

in

do

orel <- mapM (map_arel mor) arel

return $ RSRelationships orel rn

-}

-- ^ oo-style getter function for Relations

getRels :: RSScheme -> [Annoted RSRel]

getRels spec = case spec of

RSScheme _ (RSRelationships rels _) _ -> rels

-- ^ oo-style getter function for signatures

getSignature :: RSScheme -> RSTables

getSignature spec = case spec of

RSScheme tb _ _ -> tb