module LocalEnv where

import Id

import Type

import Term

-- the sub- and supertypes of a sort

data SortRels = SortRels [Type] [Type] deriving (Show,Eq)

-- the list of items which are part of a "sort-gen" (or free type)

type GenItems = [Symb]

-- real function type of a selector as Decl

data Component = Component Decl deriving (Show,Eq)

-- full function type (in Decl) of constructor

-- plus redundant (apart from partiality) component types

data Alternative = Construct Decl [Component]

| Subsort Decl

deriving (Show,Eq)

-- looseness of a datatype

-- a datatype may (only) be (sub-)part of a "sort-gen"

data GenKind = Free | Generated | Loose deriving (Show,Eq)

-- sort defined as predicate subtype or as more or less loose datatype

data SortDefn = SubsortDefn Term -- binding Term "{ x : t | p(x) }"

| Datatype [Alternative] GenKind GenItems

deriving (Show,Eq)

data SortItem = SortItem { sortDecl :: Decl

, sortRels :: SortRels

, sortDef :: Maybe SortDefn

, sortAn :: [Anno]

} deriving (Eq)

showSortItem (SortItem decl rels def an) =

shows decl . showChar ' ' . showParen True (shows rels)

. showChar ' ' . (case def of Nothing -> showString ""

Just x -> showParen True (shows x))

. showString (unwords an)

instance Show SortItem where

showsPrec _ = showSortItem

showList [] = showString ""

showList (x:r) = shows x . showList r

data OpAttr = AssocOpAttr | CommonOpAttr | IdemOpAttr | UnitOpAttr Term

deriving (Show,Eq)

-- synonyms to indicate the order of arguments

type SortId = Id

type ConsSymb = Symb

type SelSymb = Symb

-- operation defined by a Lambda-Term or generated from a datatype

-- a selector may cover several constructors/alternatives

data OpDefn = Definition Term

| Constructor SortId ConsSymb

| Selector SortId [ConsSymb] SelSymb

deriving (Show,Eq)

data OpItem = OpItem { opDecl :: Decl

, opAttrs :: [OpAttr]

, opDefn :: (Maybe OpDefn)

, opAn :: [Anno]

} deriving (Show,Eq)

type Axiom = Term -- synonyms

-- "local-var-axioms" are a special Term "forall V1,...,V2. F1 /\ F2 /\ ...

data AnItem = ASortItem SortItem

| AnOpItem OpItem

| AVarDecl VarDecl

| AnAxiom Axiom

| BeginGen | EndGen

showItem(ASortItem s) = shows s

showItem(AnOpItem o) = shows o

showItem(AVarDecl d) = shows d

showItem(AnAxiom t) = shows t

showItem BeginGen = showString "generated{"

showItem EndGen = showString "}%[generated]%"

instance Show AnItem where

showsPrec _ = showItem

showList = showSepList (showChar '\n') shows

updateAn :: AnItem -> [Anno] -> AnItem

updateAn(ASortItem s) an = ASortItem (s {sortAn = an})

updateAn(AnOpItem o) an = AnOpItem (o {opAn = an})

updateAn(AVarDecl d) an = AVarDecl (d {declAn = an})

updateAn(AnAxiom (Annotated t _)) an = AnAxiom (Annotated t an)

updateAn(AnAxiom t) an = AnAxiom (Annotated t an)

type Ast = [AnItem]

addAn :: Ast -> [Anno] -> Ast

addAn [] an = []

addAn (EndGen:r) an = EndGen : addAn r an

addAn (BeginGen:r) an = BeginGen : addAn r an

addAn (h:r) an = updateAn h an : r

data Env = Env { sorts :: [SortItem]

, ops :: [OpItem]

, vars :: [VarDecl]

, axioms :: [Axiom]

, generates :: [GenItems]

} deriving ()

showEnv (Env s o v a g) =

shows (reverse s). shows o. shows v. shows a . shows g

instance Show Env where

showsPrec _ = showEnv

addToLastGenItem :: Env -> Symb -> Env

addToLastGenItem (Env s o v a (h:r)) i =

Env s o v a ((i:h):r)

toEnv _ env [] = env

toEnv _ env (BeginGen:r) = toEnv True (env {generates = [] : generates env}) r

toEnv _ env (EndGen:r) = toEnv False env r

toEnv b env ((ASortItem s):r) =

let i = symb (sortDecl s)

env' = if b then addToLastGenItem env i else env

in toEnv b (env' {sorts = s : sorts env'}) r

toEnv b env ((AnOpItem o):r) =

let i = symb (opDecl o)

env' = if b then addToLastGenItem env i else env

in toEnv b (env' {ops = o : ops env'}) r

toEnv b env ((AVarDecl v):r) = toEnv b (env {vars = v : vars env}) r

toEnv b env ((AnAxiom a):r) = toEnv b (env {axioms = a : axioms env}) r

empty = Env [] [] [] [] []