{- |

Module : $Header$

Description : Abstract syntax for Constraint Satisfaction Problems

Copyright : (c) Tilman Thiry, Uni Freiburg 2010

License : GPLv2 or higher, see LICENSE.txt

Maintainer : thiry@informatik.uni-freiburg.de

Stability : experimental

Portability : portable

Definition of abstract syntax for constraint satisfaction problems

-}

import Common.Id as Id

import Common.Doc

import Common.DocUtils

import Common.Keywords

import Common.AS_Annotation as AS_Anno

type DOMAIN_ID = Id.Token

type RELATION_ID = Id.Token

type ELEMENT_ID = Id.Token

type VARIABLE_ID = Id.Token

data CONSTRAINT = Atomic_Constraint RELATION_ID [VARIABLE_ID] Id.Range

deriving Show

data TASK = Solve_satisfy

data FORMULA =

Constraint CONSTRAINT

| Task TASK

data BASIC_ITEMS =

Domain_item DOMAIN_ID [ELEMENT_ID] Id.Range

-- case of Domain declaration

| Relation_item RELATION_ID [DOMAIN_ID] Id.Range

-- case of relation declaration

| Definition_item RELATION_ID [[ELEMENT_ID]] Id.Range

-- case of relation definition

| Variable_item [VARIABLE_ID] DOMAIN_ID Id.Range

-- case of variable declaration

| Axiom_items [AS_Anno.Annoted (FORMULA)]