cryptol-3.3.0: src/Cryptol/TypeCheck/AST.hs
-- |
-- Module : Cryptol.TypeCheck.AST
-- Copyright : (c) 2013-2016 Galois, Inc.
-- License : BSD3
-- Maintainer : cryptol@galois.com
-- Stability : provisional
-- Portability : portable
{-# LANGUAGE Safe #-}
{-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE PatternGuards #-}
{-# LANGUAGE FlexibleInstances, FlexibleContexts #-}
{-# LANGUAGE DeriveAnyClass, DeriveGeneric #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE ViewPatterns #-}
module Cryptol.TypeCheck.AST
( module Cryptol.TypeCheck.AST
, Name()
, TFun(..)
, Selector(..)
, Import, ImportG(..), ImpName(..)
, ImportSpec(..)
, ExportType(..)
, ExportSpec(..), isExportedBind, isExportedType, isExported
, Pragma(..)
, Fixity(..)
, PrimMap(..)
, module Cryptol.TypeCheck.Type
, DocFor(..)
) where
import Data.Maybe(catMaybes)
import Cryptol.Utils.Panic(panic)
import Cryptol.Utils.Ident (Ident,isInfixIdent,ModName,PrimIdent,prelPrim)
import Cryptol.Parser.Position(Located, HasLoc(..), Range)
import Cryptol.ModuleSystem.Name
import Cryptol.ModuleSystem.NamingEnv.Types
import Cryptol.ModuleSystem.Interface
import Cryptol.ModuleSystem.Exports(ExportSpec(..)
, isExportedBind, isExportedType, isExported)
import Cryptol.Parser.AST ( Selector(..),Pragma(..)
, Import
, ImportG(..), ImportSpec(..), ExportType(..)
, Fixity(..)
, ImpName(..)
)
import Cryptol.Utils.RecordMap
import Cryptol.TypeCheck.FFI.FFIType
import Cryptol.TypeCheck.PP
import Cryptol.TypeCheck.Type
import GHC.Generics (Generic)
import Control.DeepSeq
import qualified Data.IntMap as IntMap
import Data.Map (Map)
import qualified Data.Map as Map
import Data.Maybe (mapMaybe, maybeToList, isJust)
import Data.Set (Set)
import Data.Text (Text)
data TCTopEntity =
TCTopModule (ModuleG ModName)
| TCTopSignature ModName ModParamNames
deriving (Show, Generic, NFData)
tcTopEntitytName :: TCTopEntity -> ModName
tcTopEntitytName ent =
case ent of
TCTopModule m -> mName m
TCTopSignature m _ -> m
-- | Panics if the entity is not a module
tcTopEntityToModule :: TCTopEntity -> Module
tcTopEntityToModule ent =
case ent of
TCTopModule m -> m
TCTopSignature {} -> panic "tcTopEntityToModule" [ "Not a module" ]
-- | A Cryptol module.
data ModuleG mname =
Module { mName :: !mname
, mDoc :: ![Text]
, mExports :: ExportSpec Name
-- Functors:
, mParamTypes :: Map Name ModTParam
, mParamFuns :: Map Name ModVParam
, mParamConstraints :: [Located Prop]
, mParams :: FunctorParams
-- ^ Parameters grouped by "import".
, mFunctors :: Map Name (ModuleG Name)
-- ^ Functors directly nested in this module.
-- Things further nested are in the modules in the
-- elements of the map.
, mNested :: !(Set Name)
-- ^ Submodules, functors, and interfaces nested directly
-- in this module
-- These have everything from this module and all submodules
, mTySyns :: Map Name TySyn
, mNominalTypes :: Map Name NominalType
, mDecls :: [DeclGroup]
, mSubmodules :: Map Name Submodule
, mSignatures :: !(Map Name ModParamNames)
, mInScope :: NamingEnv
-- ^ Things in scope at the top level.
-- Submodule in-scope information is in 'mSubmodules'.
} deriving (Show, Generic, NFData)
data Submodule = Submodule
{ smIface :: IfaceNames Name
, smInScope :: NamingEnv
} deriving (Show, Generic, NFData)
emptyModule :: mname -> ModuleG mname
emptyModule nm =
Module
{ mName = nm
, mDoc = mempty
, mExports = mempty
, mParams = mempty
, mParamTypes = mempty
, mParamConstraints = mempty
, mParamFuns = mempty
, mNested = mempty
, mTySyns = mempty
, mNominalTypes = mempty
, mDecls = mempty
, mFunctors = mempty
, mSubmodules = mempty
, mSignatures = mempty
, mInScope = mempty
}
-- | Find all the foreign declarations in the module and return their names and FFIFunTypes.
findForeignDecls :: ModuleG mname -> [(Name, FFIFunType)]
findForeignDecls = mapMaybe getForeign . concatMap groupDecls . mDecls
where getForeign d =
case dDefinition d of
DForeign ffiType _ -> Just (dName d, ffiType)
_ -> Nothing
-- | Find all the foreign declarations that are in functors, including in the
-- top-level module itself if it is a functor.
-- This is used to report an error
findForeignDeclsInFunctors :: ModuleG mname -> [Name]
findForeignDeclsInFunctors mo
| isParametrizedModule mo = fromM mo
| otherwise = findInSubs mo
where
findInSubs :: ModuleG mname -> [Name]
findInSubs = concatMap fromM . Map.elems . mFunctors
fromM m = map fst (findForeignDecls m) ++ findInSubs m
type Module = ModuleG ModName
-- | Is this a parameterized module?
isParametrizedModule :: ModuleG mname -> Bool
isParametrizedModule m = not (null (mParams m) &&
null (mParamTypes m) &&
null (mParamConstraints m) &&
null (mParamFuns m))
data Expr = EList [Expr] Type -- ^ List value (with type of elements)
| ETuple [Expr] -- ^ Tuple value
| ERec (RecordMap Ident Expr) -- ^ Record value
| ESel Expr Selector -- ^ Elimination for tuple/record/list
| ESet Type Expr Selector Expr -- ^ Change the value of a field.
-- The included type gives the type of the record being updated
| EIf Expr Expr Expr -- ^ If-then-else
| ECase Expr (Map Ident CaseAlt) (Maybe CaseAlt)
-- ^ Case expression. The keys are the name of constructors
-- `Nothing` for default case, the expresssions are what to
-- do if the constructor matches. If the constructor binds
-- variables, then then the expr should be `EAbs`
| EComp Type Type Expr [[Match]]
-- ^ List comprehensions
-- The types cache the length of the
-- sequence and its element type.
| EVar Name -- ^ Use of a bound variable
| ETAbs TParam Expr -- ^ Function Value
| ETApp Expr Type -- ^ Type application
| EApp Expr Expr -- ^ Function application
| EAbs Name Type Expr -- ^ Function value
| ELocated Range Expr -- ^ Source location information
{- | Proof abstraction. Because we don't keep proofs around
we don't need to name the assumption, but we still need to
record the assumption. The assumption is the 'Type' term,
which should be of kind 'KProp'.
-}
| EProofAbs {- x -} Prop Expr
{- | If @e : p => t@, then @EProofApp e : t@,
as long as we can prove @p@.
We don't record the actual proofs, as they are not
used for anything. It may be nice to keep them around
for sanity checking.
-}
| EProofApp Expr {- proof -}
| EWhere Expr [DeclGroup]
{- | Use 'ePropGuards' when constructing to get automatic
simplification of trivial constraints -}
| EPropGuards [([Prop], Expr)] Type
deriving (Show, Generic, NFData)
-- | Used for case expressions. Similar to a lambda, the variables
-- are bound by the value examined in the case.
data CaseAlt = CaseAlt [(Name,Type)] Expr
deriving (Show, Generic, NFData)
data Match = From Name Type Type Expr
-- ^ Type arguments are the length and element
-- type of the sequence expression
| Let Decl
deriving (Show, Generic, NFData)
data DeclGroup = Recursive [Decl] -- ^ Mutually recursive declarations
| NonRecursive Decl -- ^ Non-recursive declaration
deriving (Show, Generic, NFData)
groupDecls :: DeclGroup -> [Decl]
groupDecls dg = case dg of
Recursive ds -> ds
NonRecursive d -> [d]
data Decl = Decl { dName :: !Name
, dSignature :: Schema
, dDefinition :: DeclDef
, dPragmas :: [Pragma]
, dInfix :: !Bool
, dFixity :: Maybe Fixity
, dDoc :: Maybe Text
} deriving (Generic, NFData, Show)
data DeclDef = DPrim
-- | Foreign functions can have an optional cryptol
-- implementation
| DForeign FFIFunType (Maybe Expr)
| DExpr Expr
deriving (Show, Generic, NFData)
--------------------------------------------------------------------------------
-- | Construct a primitive, given a map to the unique primitive name.
ePrim :: PrimMap -> PrimIdent -> Expr
ePrim pm n = EVar (lookupPrimDecl n pm)
-- | Make an expression that is @error@ pre-applied to a type and a message.
eError :: PrimMap -> Type -> String -> Expr
eError prims t str =
EApp (ETApp (ETApp (ePrim prims (prelPrim "error")) t)
(tNum (length str))) (eString prims str)
eString :: PrimMap -> String -> Expr
eString prims str = EList (map (eChar prims) str) tChar
eChar :: PrimMap -> Char -> Expr
eChar prims c = ETApp (ETApp (ePrim prims (prelPrim "number")) (tNum v)) (tWord (tNum w))
where v = fromEnum c
w = 8 :: Int
-- | Construct a prop guard expression simplifying trivial cases.
ePropGuards :: [([Prop], Expr)] -> Type -> Expr
ePropGuards guards ty =
case check True guards of
Left body -> body
Right guards' -> EPropGuards guards' ty
where
check _ [] = Right []
check trivial ((p, e):xs)
| trivial, all (null . pSplitAnd) p = Left e
| otherwise = ((p,e):) <$> check trivial' xs
where
trivial' = trivial && any (isJust . tIsError) p
instance PP TCTopEntity where
ppPrec _ te =
case te of
TCTopModule m -> pp m
TCTopSignature x p ->
("interface" <+> pp x <+> "where") $$ nest 2 (pp p)
instance PP (WithNames Expr) where
ppPrec prec (WithNames expr nm) =
case expr of
ELocated _ t -> ppWP prec t
EList [] t -> optParens (prec > 0)
$ text "[]" <+> colon <+> ppWP prec t
EList es _ -> ppList $ map ppW es
ETuple es -> ppTuple $ map ppW es
ERec fs -> ppRecord
[ pp f <+> text "=" <+> ppW e | (f,e) <- displayFields fs ]
ESel e sel -> ppWP 4 e <.> text "." <.> pp sel
ESet _ty e sel v -> braces (pp e <+> "|" <+> pp sel <+> "=" <+> pp v)
EIf e1 e2 e3 -> optParens (prec > 0)
$ sep [ text "if" <+> ppW e1
, text "then" <+> ppW e2
, text "else" <+> ppW e3 ]
ECase e arms dflt ->
optParens (prec > 0) $
vcat [ "case" <+> pp e <+> "of"
, indent 2 (vcat ppArms $$ ppDflt)
]
where
ppArms = [ pp i <+> pp c | (i,c) <- reverse (Map.toList arms) ]
ppDflt = maybe mempty pp dflt
EComp _ _ e mss -> let arm ms = text "|" <+> commaSep (map ppW ms)
in brackets $ ppW e <+> align (vcat (map arm mss))
EVar x -> ppPrefixName x
EAbs {} -> let (xs,e) = splitWhile splitAbs expr
in ppLam nm prec [] [] xs e
EProofAbs {} -> let (ps,e1) = splitWhile splitProofAbs expr
(xs,e2) = splitWhile splitAbs e1
in ppLam nm prec [] ps xs e2
ETAbs {} -> let (ts,e1) = splitWhile splitTAbs expr
(ps,e2) = splitWhile splitProofAbs e1
(xs,e3) = splitWhile splitAbs e2
in ppLam nm prec ts ps xs e3
-- infix applications
EApp (EApp (EVar o) a) b
| isInfixIdent (nameIdent o) ->
ppPrec 3 a <+> ppInfixName o <+> ppPrec 3 b
| otherwise ->
ppPrefixName o <+> ppPrec 3 a <+> ppPrec 3 b
EApp e1 e2 -> optParens (prec > 3)
$ ppWP 3 e1 <+> ppWP 4 e2
EProofApp e -> optParens (prec > 3)
$ ppWP 3 e <+> text "<>"
ETApp e t -> optParens (prec > 3)
$ ppWP 3 e <+> ppWP 5 t
EWhere e ds -> optParens (prec > 0) $ align $ vsep $
[ ppW e
, hang "where" 2 (vcat (map ppW ds))
]
EPropGuards guards _ ->
parens (text "propguards" <+> vsep (ppGuard <$> guards))
where ppGuard (props, e) = indent 1
$ pipe <+> commaSep (ppW <$> props)
<+> text "=>" <+> ppW e
where
ppW x = ppWithNames nm x
ppWP x = ppWithNamesPrec nm x
instance PP CaseAlt where
ppPrec _ (CaseAlt xs e) = hsep (map ppV xs) <+> "->" <+> pp e
where ppV (x,t) = parens (pp x <.> ":" <+> pp t)
ppLam :: NameMap -> Int -> [TParam] -> [Prop] -> [(Name,Type)] -> Expr -> Doc
ppLam nm prec [] [] [] e = nest 2 (ppWithNamesPrec nm prec e)
ppLam nm prec ts ps xs e =
optParens (prec > 0) $
nest 2 $ sep
[ text "\\" <.> hsep (tsD ++ psD ++ xsD ++ [text "->"])
, ppWithNames ns1 e
]
where
ns1 = addTNames ts nm
tsD = if null ts then [] else [braces $ commaSep $ map ppT ts]
psD = if null ps then [] else [parens $ commaSep $ map ppP ps]
xsD = if null xs then [] else [sep $ map ppArg xs]
ppT = ppWithNames ns1
ppP = ppWithNames ns1
ppArg (x,t) = parens (pp x <+> text ":" <+> ppWithNames ns1 t)
splitWhile :: (a -> Maybe (b,a)) -> a -> ([b],a)
splitWhile f e = case f e of
Nothing -> ([], e)
Just (x,e1) -> let (xs,e2) = splitWhile f e1
in (x:xs,e2)
splitLoc :: Expr -> Maybe (Range, Expr)
splitLoc expr =
case expr of
ELocated r e -> Just (r,e)
_ -> Nothing
-- | Remove outermost locations
dropLocs :: Expr -> Expr
dropLocs = snd . splitWhile splitLoc
splitAbs :: Expr -> Maybe ((Name,Type), Expr)
splitAbs (dropLocs -> EAbs x t e) = Just ((x,t), e)
splitAbs _ = Nothing
splitApp :: Expr -> Maybe (Expr,Expr)
splitApp (dropLocs -> EApp f a) = Just (a, f)
splitApp _ = Nothing
splitTAbs :: Expr -> Maybe (TParam, Expr)
splitTAbs (dropLocs -> ETAbs t e) = Just (t, e)
splitTAbs _ = Nothing
splitProofAbs :: Expr -> Maybe (Prop, Expr)
splitProofAbs (dropLocs -> EProofAbs p e) = Just (p,e)
splitProofAbs _ = Nothing
splitTApp :: Expr -> Maybe (Type,Expr)
splitTApp (dropLocs -> ETApp e t) = Just (t, e)
splitTApp _ = Nothing
splitProofApp :: Expr -> Maybe ((), Expr)
splitProofApp (dropLocs -> EProofApp e) = Just ((), e)
splitProofApp _ = Nothing
-- | Deconstruct an expression, typically polymorphic, into
-- the types and proofs to which it is applied.
-- Since we don't store the proofs, we just return
-- the number of proof applications.
-- The first type is the one closest to the expr.
splitExprInst :: Expr -> (Expr, [Type], Int)
splitExprInst e = (e2, reverse ts, length ps)
where
(ps,e1) = splitWhile splitProofApp e
(ts,e2) = splitWhile splitTApp e1
instance HasLoc Expr where
getLoc (ELocated r _) = Just r
getLoc _ = Nothing
instance PP Expr where
ppPrec n t = ppWithNamesPrec IntMap.empty n t
instance PP (WithNames Match) where
ppPrec _ (WithNames mat nm) =
case mat of
From x _ _ e -> pp x <+> text "<-" <+> ppWithNames nm e
Let d -> text "let" <+> ppWithNames nm d
instance PP Match where
ppPrec = ppWithNamesPrec IntMap.empty
instance PP (WithNames DeclGroup) where
ppPrec _ (WithNames dg nm) =
case dg of
Recursive ds -> text "/* Recursive */"
$$ vcat (map (ppWithNames nm) ds)
$$ text ""
NonRecursive d -> text "/* Not recursive */"
$$ ppWithNames nm d
$$ text ""
instance PP DeclGroup where
ppPrec = ppWithNamesPrec IntMap.empty
instance PP (WithNames Decl) where
ppPrec _ (WithNames Decl { .. } nm) =
vcat $
[ pp dName <+> text ":" <+> ppWithNames nm dSignature ]
++ (if null dPragmas
then []
else [text "pragmas" <+> pp dName <+> sep (map pp dPragmas)])
++ [ nest 2 (sep [pp dName <+> text "=", ppWithNames nm dDefinition]) ]
instance PP (WithNames DeclDef) where
ppPrec _ (WithNames DPrim _) = text "<primitive>"
ppPrec _ (WithNames (DForeign _ me) nm) =
case me of
Just e -> text "(foreign)" <+> ppWithNames nm e
Nothing -> text "<foreign>"
ppPrec _ (WithNames (DExpr e) nm) = ppWithNames nm e
instance PP Decl where
ppPrec = ppWithNamesPrec IntMap.empty
instance PP n => PP (ModuleG n) where
ppPrec = ppWithNamesPrec IntMap.empty
instance PP n => PP (WithNames (ModuleG n)) where
ppPrec _ (WithNames Module { .. } nm) =
vcat $
catMaybes
[ Just (text "module" <+> pp mName)
, Just ""
-- XXX: Print exports?
, vcat' (map pp' (Map.elems mTySyns))
-- XXX: Print abstarct types/functions
, vcat' (map pp' mDecls)
, vcat' (map pp (Map.elems mFunctors))
, vcat' (map ppSig (Map.toList mSignatures))
]
where mps = map mtpParam (Map.elems mParamTypes)
pp' :: PP (WithNames a) => a -> Doc
pp' = ppWithNames (addTNames mps nm)
ppSig (x,y) = "interface module" <+> pp x <+> "where"
$$ indent 2 (pp y)
vcat' xs = if null xs then Nothing else Just (vcat xs)
instance PP (WithNames TCTopEntity) where
ppPrec _ (WithNames ent nm) =
case ent of
TCTopModule m -> ppWithNames nm m
TCTopSignature n ps ->
hang ("interface module" <+> pp n <+> "where") 2 (pp ps)
data DocItem = DocItem
{ docModContext :: ImpName Name -- ^ The module scope to run repl commands in
, docFor :: DocFor -- ^ The name the documentation is attached to
, docText :: [Text] -- ^ The text of the attached docstring, if any
}
data DocFor
= DocForMod (ImpName Name)
| DocForDef Name -- definitions that aren't modules
instance PP DocFor where
ppPrec p x =
case x of
DocForMod m -> ppPrec p m
DocForDef n -> ppPrec p n
gatherModuleDocstrings ::
Map Name (ImpName Name) ->
Module ->
[DocItem]
gatherModuleDocstrings nameToModule m =
[DocItem
{ docModContext = ImpTop (mName m)
, docFor = DocForMod (ImpTop (mName m))
, docText = mDoc m
}
] ++
-- mParams m
-- mParamTypes m
-- mParamFuns m
[DocItem
{ docModContext = lookupModuleName n
, docFor = DocForDef n
, docText = maybeToList (tsDoc t)
} | (n, t) <- Map.assocs (mTySyns m)] ++
[DocItem
{ docModContext = lookupModuleName n
, docFor = DocForDef n
, docText = maybeToList (ntDoc t)
} | (n, t) <- Map.assocs (mNominalTypes m)] ++
[DocItem
{ docModContext = lookupModuleName (dName d)
, docFor = DocForDef (dName d)
, docText = maybeToList (dDoc d)
} | g <- mDecls m, d <- groupDecls g] ++
[DocItem
{ docModContext = ImpNested n
, docFor = DocForMod (ImpNested n)
, docText = ifsDoc (smIface s)
} | (n, s) <- Map.assocs (mSubmodules m)] ++
[DocItem
{ docModContext = ImpTop (mName m)
, docFor = DocForMod (ImpNested n)
, docText = maybeToList (mpnDoc s)
} | (n, s) <- Map.assocs (mSignatures m)]
where
lookupModuleName n =
case Map.lookup n nameToModule of
Just x -> x
Nothing -> panic "gatherModuleDocstrings" ["No owning module for name:", show (pp n)]