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Idris-dev/src/Idris/Core/TT.hs
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1{-# LANGUAGE MultiParamTypeClasses, FunctionalDependencies, DeriveFunctor #-}
3{-| TT is the core language of Idris. The language has:
5 * Full dependent types
7 * A hierarchy of universes, with cumulativity: Type : Type1, Type1 : Type2, ...
9 * Pattern matching letrec binding
11 * (primitive types defined externally)
13 Some technical stuff:
15 * Typechecker is kept as simple as possible - no unification, just a checker for incomplete terms.
17 * We have a simple collection of tactics which we use to elaborate source
18 programs with implicit syntax into fully explicit terms.
19-}
21module Idris.Core.TT(module Idris.Core.TT, module Idris.Core.TC) where
23import Idris.Core.TC
25import Control.Monad.State.Strict
26import Control.Monad.Trans.Error (Error(..))
27import Debug.Trace
28import qualified Data.Map.Strict as Map
29import Data.Char
30import qualified Data.Text as T
31import Data.List
32import Data.Maybe (listToMaybe)
33import Data.Vector.Unboxed (Vector)
34import qualified Data.Vector.Unboxed as V
35import qualified Data.Binary as B
36import Data.Binary hiding (get, put)
37import Foreign.Storable (sizeOf)
39import Util.Pretty hiding (Str)
41data Option = TTypeInTType
42 | CheckConv
43 deriving Eq
45-- | Source location. These are typically produced by the parser 'Idris.Parser.getFC'
46data FC = FC { fc_fname :: String, -- ^ Filename
47 fc_start :: (Int, Int), -- ^ Line and column numbers for the start of the location span
48 fc_end :: (Int, Int) -- ^ Line and column numbers for the end of the location span
49 }
51-- | Ignore source location equality (so deriving classes do not compare FCs)
52instance Eq FC where
53 _ == _ = True
55-- | FC with equality
56newtype FC' = FC' { unwrapFC :: FC }
58instance Eq FC' where
59 FC' fc == FC' fc' = fcEq fc fc'
60 where fcEq (FC n s e) (FC n' s' e') = n == n' && s == s' && e == e'
62-- | Empty source location
63emptyFC :: FC
64emptyFC = fileFC ""
66-- | Source location with file only
67fileFC :: String -> FC
68fileFC s = FC s (0, 0) (0, 0)
70{-!
71deriving instance Binary FC
72deriving instance NFData FC
73!-}
75instance Sized FC where
76 size (FC f s e) = 4 + length f
78instance Show FC where
79 show (FC f s e) = f ++ ":" ++ showLC s e
80 where showLC (sl, sc) (el, ec) | sl == el && sc == ec = show sl ++ ":" ++ show sc
81 | sl == el = show sl ++ ":" ++ show sc ++ "-" ++ show ec
82 | otherwise = show sl ++ ":" ++ show sc ++ "-" ++ show el ++ ":" ++ show ec
84-- | Output annotation for pretty-printed name - decides colour
85data NameOutput = TypeOutput | FunOutput | DataOutput | MetavarOutput
87-- | Text formatting output
88data TextFormatting = BoldText | ItalicText | UnderlineText
90-- | Output annotations for pretty-printing
91data OutputAnnotation = AnnName Name (Maybe NameOutput) (Maybe String) (Maybe String)
92 -- ^^ The name, classification, docs overview, and pretty-printed type
93 | AnnBoundName Name Bool
94 -- ^^ The name and whether it is implicit
95 | AnnConstData
96 | AnnConstType
97 | AnnKeyword
98 | AnnFC FC
99 | AnnTextFmt TextFormatting
101-- | Used for error reflection
102data ErrorReportPart = TextPart String
103 | NamePart Name
104 | TermPart Term
105 | SubReport [ErrorReportPart]
106 deriving (Show, Eq)
109-- Please remember to keep Err synchronised with
110-- Language.Reflection.Errors.Err in the stdlib!
112-- | Idris errors. Used as exceptions in the compiler, but reported to users
113-- if they reach the top level.
114data Err' t
115 = Msg String
116 | InternalMsg String
117 | CantUnify Bool t t (Err' t) [(Name, t)] Int
118 -- Int is 'score' - how much we did unify
119 -- Bool indicates recoverability, True indicates more info may make
120 -- unification succeed
121 | InfiniteUnify Name t [(Name, t)]
122 | CantConvert t t [(Name, t)]
123 | CantSolveGoal t [(Name, t)]
124 | UnifyScope Name Name t [(Name, t)]
125 | CantInferType String
126 | NonFunctionType t t
127 | NotEquality t t
128 | TooManyArguments Name
129 | CantIntroduce t
130 | NoSuchVariable Name
131 | NoTypeDecl Name
132 | NotInjective t t t
133 | CantResolve t
134 | CantResolveAlts [String]
135 | IncompleteTerm t
136 | UniverseError
137 | ProgramLineComment
138 | Inaccessible Name
139 | NonCollapsiblePostulate Name
140 | AlreadyDefined Name
141 | ProofSearchFail (Err' t)
142 | NoRewriting t
143 | At FC (Err' t)
144 | Elaborating String Name (Err' t)
145 | ElaboratingArg Name Name [(Name, Name)] (Err' t)
146 | ProviderError String
147 | LoadingFailed String (Err' t)
148 | ReflectionError [[ErrorReportPart]] (Err' t)
149 | ReflectionFailed String (Err' t)
150 deriving (Eq, Functor)
152type Err = Err' Term
154{-!
155deriving instance NFData Err
156!-}
158instance Sized Err where
159 size (Msg msg) = length msg
160 size (InternalMsg msg) = length msg
161 size (CantUnify _ left right err _ score) = size left + size right + size err
162 size (InfiniteUnify _ right _) = size right
163 size (CantConvert left right _) = size left + size right
164 size (UnifyScope _ _ right _) = size right
165 size (NoSuchVariable name) = size name
166 size (NoTypeDecl name) = size name
167 size (NotInjective l c r) = size l + size c + size r
168 size (CantResolve trm) = size trm
169 size (NoRewriting trm) = size trm
170 size (CantResolveAlts _) = 1
171 size (IncompleteTerm trm) = size trm
172 size UniverseError = 1
173 size ProgramLineComment = 1
174 size (At fc err) = size fc + size err
175 size (Elaborating _ n err) = size err
176 size (ElaboratingArg _ _ _ err) = size err
177 size (ProviderError msg) = length msg
178 size (LoadingFailed fn e) = 1 + length fn + size e
179 size _ = 1
181score :: Err -> Int
182score (CantUnify _ _ _ m _ s) = s + score m
183score (CantResolve _) = 20
184score (NoSuchVariable _) = 1000
185score (ProofSearchFail _) = 10000
186score (CantSolveGoal _ _) = 10000
187score (InternalMsg _) = -1
188score _ = 0
190instance Show Err where
191 show (Msg s) = s
192 show (InternalMsg s) = "Internal error: " ++ show s
193 show (CantUnify _ l r e sc i) = "CantUnify " ++ show l ++ " " ++ show r ++ " "
194 ++ show e ++ " in " ++ show sc ++ " " ++ show i
195 show (CantSolveGoal g _) = "CantSolve " ++ show g
196 show (Inaccessible n) = show n ++ " is not an accessible pattern variable"
197 show (ProviderError msg) = "Type provider error: " ++ msg
198 show (LoadingFailed fn e) = "Loading " ++ fn ++ " failed: (TT) " ++ show e
199 show ProgramLineComment = "Program line next to comment"
200 show (At f e) = show f ++ ":" ++ show e
201 show (ElaboratingArg f x prev e) = "Elaborating " ++ show f ++ " arg " ++
202 show x ++ ": " ++ show e
203 show (Elaborating what n e) = "Elaborating " ++ what ++ show n ++ ":" ++ show e
204 show _ = "Error"
206instance Pretty Err OutputAnnotation where
207 pretty (Msg m) = text m
208 pretty (CantUnify _ l r e _ i) =
209 text "Cannot unify" <+> colon <+> pretty l <+> text "and" <+> pretty r <+>
210 nest nestingSize (text "where" <+> pretty e <+> text "with" <+> (text . show $ i))
211 pretty (ProviderError msg) = text msg
212 pretty err@(LoadingFailed _ _) = text (show err)
213 pretty _ = text "Error"
215instance Error Err where
216 strMsg = InternalMsg
218type TC = TC' Err
220instance (Pretty a OutputAnnotation) => Pretty (TC a) OutputAnnotation where
221 pretty (OK ok) = pretty ok
222 pretty (Error err) =
223 text "Error" <+> colon <+> pretty err
225instance Show a => Show (TC a) where
226 show (OK x) = show x
227 show (Error str) = "Error: " ++ show str
229tfail :: Err -> TC a
230tfail e = Error e
232failMsg :: String -> TC a
233failMsg str = Error (Msg str)
235trun :: FC -> TC a -> TC a
236trun fc (OK a) = OK a
237trun fc (Error e) = Error (At fc e)
239discard :: Monad m => m a -> m ()
240discard f = f >> return ()
242showSep :: String -> [String] -> String
243showSep sep [] = ""
244showSep sep [x] = x
245showSep sep (x:xs) = x ++ sep ++ showSep sep xs
247pmap f (x, y) = (f x, f y)
249traceWhen True msg a = trace msg a
250traceWhen False _ a = a
252-- RAW TERMS ----------------------------------------------------------------
254-- | Names are hierarchies of strings, describing scope (so no danger of
255-- duplicate names, but need to be careful on lookup).
256data Name = UN T.Text -- ^ User-provided name
257 | NS Name [T.Text] -- ^ Root, namespaces
258 | MN Int T.Text -- ^ Machine chosen names
259 | NErased -- ^ Name of somethng which is never used in scope
260 | SN SpecialName -- ^ Decorated function names
261 | SymRef Int -- ^ Reference to IBC file symbol table (used during serialisation)
262 deriving (Eq, Ord)
264txt :: String -> T.Text
265txt = T.pack
267str :: T.Text -> String
268str = T.unpack
270tnull :: T.Text -> Bool
271tnull = T.null
273thead :: T.Text -> Char
274thead = T.head
276-- Smart constructors for names, using old String style
277sUN :: String -> Name
278sUN s = UN (txt s)
280sNS :: Name -> [String] -> Name
281sNS n ss = NS n (map txt ss)
283sMN :: Int -> String -> Name
284sMN i s = MN i (txt s)
286{-!
287deriving instance Binary Name
288deriving instance NFData Name
289!-}
291data SpecialName = WhereN Int Name Name
292 | InstanceN Name [T.Text]
293 | ParentN Name T.Text
294 | MethodN Name
295 | CaseN Name
296 | ElimN Name
297 | InstanceCtorN Name
298 deriving (Eq, Ord)
299{-!
300deriving instance Binary SpecialName
301deriving instance NFData SpecialName
302!-}
304sInstanceN :: Name -> [String] -> SpecialName
305sInstanceN n ss = InstanceN n (map T.pack ss)
307sParentN :: Name -> String -> SpecialName
308sParentN n s = ParentN n (T.pack s)
310instance Sized Name where
311 size (UN n) = 1
312 size (NS n els) = 1 + length els
313 size (MN i n) = 1
314 size _ = 1
316instance Pretty Name OutputAnnotation where
317 pretty n@(UN n') = annotate (AnnName n Nothing Nothing Nothing) $ text (T.unpack n')
318 pretty n@(NS un s) = annotate (AnnName n Nothing Nothing Nothing) . noAnnotate $ pretty un
319 pretty n@(MN i s) = annotate (AnnName n Nothing Nothing Nothing) $
320 lbrace <+> text (T.unpack s) <+> (text . show $ i) <+> rbrace
321 pretty n@(SN s) = annotate (AnnName n Nothing Nothing Nothing) $ text (show s)
323instance Pretty [Name] OutputAnnotation where
324 pretty = encloseSep empty empty comma . map pretty
326instance Show Name where
327 show (UN n) = str n
328 show (NS n s) = showSep "." (map T.unpack (reverse s)) ++ "." ++ show n
329 show (MN _ u) | u == txt "underscore" = "_"
330 show (MN i s) = "{" ++ str s ++ show i ++ "}"
331 show (SN s) = show s
332 show NErased = "_"
334instance Show SpecialName where
335 show (WhereN i p c) = show p ++ ", " ++ show c
336 show (InstanceN cl inst) = showSep ", " (map T.unpack inst) ++ " instance of " ++ show cl
337 show (MethodN m) = "method " ++ show m
338 show (ParentN p c) = show p ++ "#" ++ T.unpack c
339 show (CaseN n) = "case block in " ++ show n
340 show (ElimN n) = "<<" ++ show n ++ " eliminator>>"
341 show (InstanceCtorN n) = "constructor of " ++ show n
343-- Show a name in a way decorated for code generation, not human reading
344showCG :: Name -> String
345showCG (UN n) = T.unpack n
346showCG (NS n s) = showSep "." (map T.unpack (reverse s)) ++ "." ++ showCG n
347showCG (MN _ u) | u == txt "underscore" = "_"
348showCG (MN i s) = "{" ++ T.unpack s ++ show i ++ "}"
349showCG (SN s) = showCG' s
350 where showCG' (WhereN i p c) = showCG p ++ ":" ++ showCG c ++ ":" ++ show i
351 showCG' (InstanceN cl inst) = '@':showCG cl ++ '$':showSep ":" (map T.unpack inst)
352 showCG' (MethodN m) = '!':showCG m
353 showCG' (ParentN p c) = showCG p ++ "#" ++ show c
354 showCG' (CaseN c) = showCG c ++ "_case"
355 showCG' (ElimN sn) = showCG sn ++ "_elim"
356showCG NErased = "_"
359-- |Contexts allow us to map names to things. A root name maps to a collection
360-- of things in different namespaces with that name.
361type Ctxt a = Map.Map Name (Map.Map Name a)
362emptyContext = Map.empty
364mapCtxt :: (a -> b) -> Ctxt a -> Ctxt b
365mapCtxt = fmap . fmap
367-- |Return True if the argument 'Name' should be interpreted as the name of a
368-- typeclass.
369tcname (UN xs) | T.null xs = False
370 | otherwise = T.head xs == '@'
371tcname (NS n _) = tcname n
372tcname (SN (InstanceN _ _)) = True
373tcname (SN (MethodN _)) = True
374tcname (SN (ParentN _ _)) = True
375tcname _ = False
377implicitable (NS n _) = implicitable n
378implicitable (UN xs) | T.null xs = False
379 | otherwise = isLower (T.head xs)
380implicitable (MN _ _) = True
381implicitable _ = False
383nsroot (NS n _) = n
384nsroot n = n
386addDef :: Name -> a -> Ctxt a -> Ctxt a
387addDef n v ctxt = case Map.lookup (nsroot n) ctxt of
388 Nothing -> Map.insert (nsroot n)
389 (Map.insert n v Map.empty) ctxt
390 Just xs -> Map.insert (nsroot n)
391 (Map.insert n v xs) ctxt
393{-| Look up a name in the context, given an optional namespace.
394 The name (n) may itself have a (partial) namespace given.
396 Rules for resolution:
398 - if an explicit namespace is given, return the names which match it. If none
399 match, return all names.
401 - if the name has has explicit namespace given, return the names which match it
402 and ignore the given namespace.
404 - otherwise, return all names.
406-}
408lookupCtxtName :: Name -> Ctxt a -> [(Name, a)]
409lookupCtxtName n ctxt = case Map.lookup (nsroot n) ctxt of
410 Just xs -> filterNS (Map.toList xs)
411 Nothing -> []
412 where
413 filterNS [] = []
414 filterNS ((found, v) : xs)
415 | nsmatch n found = (found, v) : filterNS xs
416 | otherwise = filterNS xs
418 nsmatch (NS n ns) (NS p ps) = ns `isPrefixOf` ps
419 nsmatch (NS _ _) _ = False
420 nsmatch looking found = True
422lookupCtxt :: Name -> Ctxt a -> [a]
423lookupCtxt n ctxt = map snd (lookupCtxtName n ctxt)
425lookupCtxtExact :: Name -> Ctxt a -> Maybe a
426lookupCtxtExact n ctxt = listToMaybe [ v | (nm, v) <- lookupCtxtName n ctxt, nm == n]
428updateDef :: Name -> (a -> a) -> Ctxt a -> Ctxt a
429updateDef n f ctxt
430 = let ds = lookupCtxtName n ctxt in
431 foldr (\ (n, t) c -> addDef n (f t) c) ctxt ds
433toAlist :: Ctxt a -> [(Name, a)]
434toAlist ctxt = let allns = map snd (Map.toList ctxt) in
435 concat (map (Map.toList) allns)
437addAlist :: Show a => [(Name, a)] -> Ctxt a -> Ctxt a
438addAlist [] ctxt = ctxt
439addAlist ((n, tm) : ds) ctxt = addDef n tm (addAlist ds ctxt)
441data NativeTy = IT8 | IT16 | IT32 | IT64
442 deriving (Show, Eq, Ord, Enum)
444instance Pretty NativeTy OutputAnnotation where
445 pretty IT8 = text "Bits8"
446 pretty IT16 = text "Bits16"
447 pretty IT32 = text "Bits32"
448 pretty IT64 = text "Bits64"
450data IntTy = ITFixed NativeTy | ITNative | ITBig | ITChar
451 | ITVec NativeTy Int
452 deriving (Show, Eq, Ord)
454intTyName :: IntTy -> String
455intTyName ITNative = "Int"
456intTyName ITBig = "BigInt"
457intTyName (ITFixed sized) = "B" ++ show (nativeTyWidth sized)
458intTyName (ITChar) = "Char"
459intTyName (ITVec ity count) = "B" ++ show (nativeTyWidth ity) ++ "x" ++ show count
461data ArithTy = ATInt IntTy | ATFloat -- TODO: Float vectors
462 deriving (Show, Eq, Ord)
463{-!
464deriving instance NFData IntTy
465deriving instance NFData NativeTy
466deriving instance NFData ArithTy
467!-}
469instance Pretty ArithTy OutputAnnotation where
470 pretty (ATInt ITNative) = text "Int"
471 pretty (ATInt ITBig) = text "BigInt"
472 pretty (ATInt ITChar) = text "Char"
473 pretty (ATInt (ITFixed n)) = pretty n
474 pretty (ATInt (ITVec e c)) = pretty e <> text "x" <> (text . show $ c)
475 pretty ATFloat = text "Float"
477nativeTyWidth :: NativeTy -> Int
478nativeTyWidth IT8 = 8
479nativeTyWidth IT16 = 16
480nativeTyWidth IT32 = 32
481nativeTyWidth IT64 = 64
483{-# DEPRECATED intTyWidth "Non-total function, use nativeTyWidth and appropriate casing" #-}
484intTyWidth :: IntTy -> Int
485intTyWidth (ITFixed n) = nativeTyWidth n
486intTyWidth ITNative = 8 * sizeOf (0 :: Int)
487intTyWidth ITChar = error "IRTS.Lang.intTyWidth: Characters have platform and backend dependent width"
488intTyWidth ITBig = error "IRTS.Lang.intTyWidth: Big integers have variable width"
490data Const = I Int | BI Integer | Fl Double | Ch Char | Str String
491 | B8 Word8 | B16 Word16 | B32 Word32 | B64 Word64
492 | B8V (Vector Word8) | B16V (Vector Word16)
493 | B32V (Vector Word32) | B64V (Vector Word64)
494 | AType ArithTy | StrType
495 | PtrType | ManagedPtrType | BufferType | VoidType | Forgot
496 deriving (Eq, Ord)
497{-!
498deriving instance Binary Const
499deriving instance NFData Const
500!-}
502instance Sized Const where
503 size _ = 1
505instance Pretty Const OutputAnnotation where
506 pretty (I i) = text . show $ i
507 pretty (BI i) = text . show $ i
508 pretty (Fl f) = text . show $ f
509 pretty (Ch c) = text . show $ c
510 pretty (Str s) = text s
511 pretty (AType a) = pretty a
512 pretty StrType = text "String"
513 pretty BufferType = text "prim__UnsafeBuffer"
514 pretty PtrType = text "Ptr"
515 pretty ManagedPtrType = text "Ptr"
516 pretty VoidType = text "Void"
517 pretty Forgot = text "Forgot"
518 pretty (B8 w) = text . show $ w
519 pretty (B16 w) = text . show $ w
520 pretty (B32 w) = text . show $ w
521 pretty (B64 w) = text . show $ w
523data Raw = Var Name
524 | RBind Name (Binder Raw) Raw
525 | RApp Raw Raw
526 | RType
527 | RForce Raw
528 | RConstant Const
529 deriving (Show, Eq)
531instance Sized Raw where
532 size (Var name) = 1
533 size (RBind name bind right) = 1 + size bind + size right
534 size (RApp left right) = 1 + size left + size right
535 size RType = 1
536 size (RForce raw) = 1 + size raw
537 size (RConstant const) = size const
539instance Pretty Raw OutputAnnotation where
540 pretty = text . show
542{-!
543deriving instance Binary Raw
544deriving instance NFData Raw
545!-}
547-- The type parameter `b` will normally be something like `TT Name` or just
548-- `Raw`. We do not make a type-level distinction between TT terms that happen
549-- to be TT types and TT terms that are not TT types.
550-- | All binding forms are represented in a uniform fashion. This type only represents
551-- the types of bindings (and their values, if any); the attached identifiers are part
552-- of the 'Bind' constructor for the 'TT' type.
553data Binder b = Lam { binderTy :: !b {-^ type annotation for bound variable-}}
554 | Pi { binderTy :: !b }
555 {-^ A binding that occurs in a function type expression, e.g. @(x:Int) -> ...@ -}
556 | Let { binderTy :: !b,
557 binderVal :: b {-^ value for bound variable-}}
558 -- ^ A binding that occurs in a @let@ expression
559 | NLet { binderTy :: !b,
560 binderVal :: b }
561 | Hole { binderTy :: !b}
562 | GHole { envlen :: Int,
563 binderTy :: !b}
564 | Guess { binderTy :: !b,
565 binderVal :: b }
566 | PVar { binderTy :: !b }
567 -- ^ A pattern variable
568 | PVTy { binderTy :: !b }
569 deriving (Show, Eq, Ord, Functor)
570{-!
571deriving instance Binary Binder
572deriving instance NFData Binder
573!-}
575instance Sized a => Sized (Binder a) where
576 size (Lam ty) = 1 + size ty
577 size (Pi ty) = 1 + size ty
578 size (Let ty val) = 1 + size ty + size val
579 size (NLet ty val) = 1 + size ty + size val
580 size (Hole ty) = 1 + size ty
581 size (GHole _ ty) = 1 + size ty
582 size (Guess ty val) = 1 + size ty + size val
583 size (PVar ty) = 1 + size ty
584 size (PVTy ty) = 1 + size ty
586fmapMB :: Monad m => (a -> m b) -> Binder a -> m (Binder b)
587fmapMB f (Let t v) = liftM2 Let (f t) (f v)
588fmapMB f (NLet t v) = liftM2 NLet (f t) (f v)
589fmapMB f (Guess t v) = liftM2 Guess (f t) (f v)
590fmapMB f (Lam t) = liftM Lam (f t)
591fmapMB f (Pi t) = liftM Pi (f t)
592fmapMB f (Hole t) = liftM Hole (f t)
593fmapMB f (GHole i t) = liftM (GHole i) (f t)
594fmapMB f (PVar t) = liftM PVar (f t)
595fmapMB f (PVTy t) = liftM PVTy (f t)
597raw_apply :: Raw -> [Raw] -> Raw
598raw_apply f [] = f
599raw_apply f (a : as) = raw_apply (RApp f a) as
601raw_unapply :: Raw -> (Raw, [Raw])
602raw_unapply t = ua [] t where
603 ua args (RApp f a) = ua (a:args) f
604 ua args t = (t, args)
606-- WELL TYPED TERMS ---------------------------------------------------------
608-- | Universe expressions for universe checking
609data UExp = UVar Int -- ^ universe variable
610 | UVal Int -- ^ explicit universe level
611 deriving (Eq, Ord)
612{-!
613deriving instance NFData UExp
614!-}
616instance Sized UExp where
617 size _ = 1
619-- We assume that universe levels have been checked, so anything external
620-- can just have the same universe variable and we won't get any new
621-- cycles.
623instance Binary UExp where
624 put x = return ()
625 get = return (UVar (-1))
627instance Show UExp where
628 show (UVar x) | x < 26 = [toEnum (x + fromEnum 'a')]
629 | otherwise = toEnum ((x `mod` 26) + fromEnum 'a') : show (x `div` 26)
630 show (UVal x) = show x
631-- show (UMax l r) = "max(" ++ show l ++ ", " ++ show r ++")"
633-- | Universe constraints
634data UConstraint = ULT UExp UExp -- ^ Strictly less than
635 | ULE UExp UExp -- ^ Less than or equal to
636 deriving Eq
638instance Show UConstraint where
639 show (ULT x y) = show x ++ " < " ++ show y
640 show (ULE x y) = show x ++ " <= " ++ show y
642type UCs = (Int, [UConstraint])
644data NameType = Bound
645 | Ref
646 | DCon {nt_tag :: Int, nt_arity :: Int} -- ^ Data constructor
647 | TCon {nt_tag :: Int, nt_arity :: Int} -- ^ Type constructor
648 deriving (Show, Ord)
649{-!
650deriving instance Binary NameType
651deriving instance NFData NameType
652!-}
654instance Sized NameType where
655 size _ = 1
657instance Pretty NameType OutputAnnotation where
658 pretty = text . show
660instance Eq NameType where
661 Bound == Bound = True
662 Ref == Ref = True
663 DCon _ a == DCon _ b = (a == b) -- ignore tag
664 TCon _ a == TCon _ b = (a == b) -- ignore tag
665 _ == _ = False
667-- | Terms in the core language. The type parameter is the type of
668-- identifiers used for bindings and explicit named references;
669-- usually we use @TT 'Name'@.
670data TT n = P NameType n (TT n) -- ^ named references with type
671 -- (P for "Parameter", motivated by McKinna and Pollack's
672 -- Pure Type Systems Formalized)
673 | V !Int -- ^ a resolved de Bruijn-indexed variable
674 | Bind n !(Binder (TT n)) (TT n) -- ^ a binding
675 | App !(TT n) (TT n) -- ^ function, function type, arg
676 | Constant Const -- ^ constant
677 | Proj (TT n) !Int -- ^ argument projection; runtime only
678 -- (-1) is a special case for 'subtract one from BI'
679 | Erased -- ^ an erased term
680 | Impossible -- ^ special case for totality checking
681 | TType UExp -- ^ the type of types at some level
682 deriving (Ord, Functor)
683{-!
684deriving instance Binary TT
685deriving instance NFData TT
686!-}
688class TermSize a where
689 termsize :: Name -> a -> Int
691instance TermSize a => TermSize [a] where
692 termsize n [] = 0
693 termsize n (x : xs) = termsize n x + termsize n xs
695instance TermSize (TT Name) where
696 termsize n (P _ n' _)
697 | n' == n = 1000000 -- recursive => really big
698 | otherwise = 1
699 termsize n (V _) = 1
700 -- for `Bind` terms, we can erroneously declare a term
701 -- "recursive => really big" if the name of the bound
702 -- variable is the same as the name we're using
703 -- So generate a different name in that case.
704 termsize n (Bind n' (Let t v) sc)
705 = let rn = if n == n' then sMN 0 "noname" else n in
706 termsize rn v + termsize rn sc
707 termsize n (Bind n' b sc)
708 = let rn = if n == n' then sMN 0 "noname" else n in
709 termsize rn sc
710 termsize n (App f a) = termsize n f + termsize n a
711 termsize n (Proj t i) = termsize n t
712 termsize n _ = 1
714instance Sized a => Sized (TT a) where
715 size (P name n trm) = 1 + size name + size n + size trm
716 size (V v) = 1
717 size (Bind nm binder bdy) = 1 + size nm + size binder + size bdy
718 size (App l r) = 1 + size l + size r
719 size (Constant c) = size c
720 size Erased = 1
721 size (TType u) = 1 + size u
723instance Pretty a o => Pretty (TT a) o where
724 pretty _ = text "test"
726type EnvTT n = [(n, Binder (TT n))]
728data Datatype n = Data { d_typename :: n,
729 d_typetag :: Int,
730 d_type :: (TT n),
731 d_cons :: [(n, TT n)] }
732 deriving (Show, Functor, Eq)
734instance Eq n => Eq (TT n) where
735 (==) (P xt x _) (P yt y _) = x == y
736 (==) (V x) (V y) = x == y
737 (==) (Bind _ xb xs) (Bind _ yb ys) = xs == ys && xb == yb
738 (==) (App fx ax) (App fy ay) = ax == ay && fx == fy
739 (==) (TType _) (TType _) = True -- deal with constraints later
740 (==) (Constant x) (Constant y) = x == y
741 (==) (Proj x i) (Proj y j) = x == y && i == j
742 (==) Erased _ = True
743 (==) _ Erased = True
744 (==) _ _ = False
746-- * A few handy operations on well typed terms:
748-- | A term is injective iff it is a data constructor, type constructor,
749-- constant, the type Type, pi-binding, or an application of an injective
750-- term.
751isInjective :: TT n -> Bool
752isInjective (P (DCon _ _) _ _) = True
753isInjective (P (TCon _ _) _ _) = True
754isInjective (Constant _) = True
755isInjective (TType x) = True
756isInjective (Bind _ (Pi _) sc) = True
757isInjective (App f a) = isInjective f
758isInjective _ = False
760-- | Count the number of instances of a de Bruijn index in a term
761vinstances :: Int -> TT n -> Int
762vinstances i (V x) | i == x = 1
763vinstances i (App f a) = vinstances i f + vinstances i a
764vinstances i (Bind x b sc) = instancesB b + vinstances (i + 1) sc
765 where instancesB (Let t v) = vinstances i v
766 instancesB _ = 0
767vinstances i t = 0
769-- | Replace the outermost (index 0) de Bruijn variable with the given term
770instantiate :: TT n -> TT n -> TT n
771instantiate e = subst 0 where
772 subst i (V x) | i == x = e
773 subst i (Bind x b sc) = Bind x (fmap (subst i) b) (subst (i+1) sc)
774 subst i (App f a) = App (subst i f) (subst i a)
775 subst i (Proj x idx) = Proj (subst i x) idx
776 subst i t = t
778-- | As 'instantiate', but also decrement the indices of all de Bruijn variables
779-- remaining in the term, so that there are no more references to the variable
780-- that has been substituted.
781substV :: TT n -> TT n -> TT n
782substV x tm = dropV 0 (instantiate x tm) where
783 dropV i (V x) | x > i = V (x - 1)
784 | otherwise = V x
785 dropV i (Bind x b sc) = Bind x (fmap (dropV i) b) (dropV (i+1) sc)
786 dropV i (App f a) = App (dropV i f) (dropV i a)
787 dropV i (Proj x idx) = Proj (dropV i x) idx
788 dropV i t = t
790-- | Replace all non-free de Bruijn references in the given term with references
791-- to the name of their binding.
792explicitNames :: TT n -> TT n
793explicitNames (Bind x b sc) = let b' = fmap explicitNames b in
794 Bind x b'
795 (explicitNames (instantiate
796 (P Bound x (binderTy b')) sc))
797explicitNames (App f a) = App (explicitNames f) (explicitNames a)
798explicitNames (Proj x idx) = Proj (explicitNames x) idx
799explicitNames t = t
801-- | Replace references to the given 'Name'-like id with references to
802-- de Bruijn index 0.
803pToV :: Eq n => n -> TT n -> TT n
804pToV n = pToV' n 0
805pToV' n i (P _ x _) | n == x = V i
806pToV' n i (Bind x b sc)
807-- We can assume the inner scope has been pToVed already, so continue to
808-- resolve names from the *outer* scope which may happen to have the same id.
809 | n == x = Bind x (fmap (pToV' n i) b) sc
810 | otherwise = Bind x (fmap (pToV' n i) b) (pToV' n (i+1) sc)
811pToV' n i (App f a) = App (pToV' n i f) (pToV' n i a)
812pToV' n i (Proj t idx) = Proj (pToV' n i t) idx
813pToV' n i t = t
815-- increase de Bruijn indices, as if a binder has been added
816addBinder :: TT n -> TT n
817addBinder t = ab 0 t
818 where
819 ab top (V i) | i >= top = V (i + 1)
820 | otherwise = V i
821 ab top (Bind x b sc) = Bind x (fmap (ab top) b) (ab (top + 1) sc)
822 ab top (App f a) = App (ab top f) (ab top a)
823 ab top (Proj t idx) = Proj (ab top t) idx
824 ab top t = t
826-- | Convert several names. First in the list comes out as V 0
827pToVs :: Eq n => [n] -> TT n -> TT n
828pToVs ns tm = pToVs' ns tm 0 where
829 pToVs' [] tm i = tm
830 pToVs' (n:ns) tm i = pToV' n i (pToVs' ns tm (i+1))
832-- | Replace de Bruijn indices in the given term with explicit references to
833-- the names of the bindings they refer to. It is an error if the given term
834-- contains free de Bruijn indices.
835vToP :: TT n -> TT n
836vToP = vToP' [] where
837 vToP' env (V i) = let (n, b) = (env !! i) in
838 P Bound n (binderTy b)
839 vToP' env (Bind n b sc) = let b' = fmap (vToP' env) b in
840 Bind n b' (vToP' ((n, b'):env) sc)
841 vToP' env (App f a) = App (vToP' env f) (vToP' env a)
842 vToP' env t = t
844-- | Replace every non-free reference to the name of a binding in
845-- the given term with a de Bruijn index.
846finalise :: Eq n => TT n -> TT n
847finalise (Bind x b sc) = Bind x (fmap finalise b) (pToV x (finalise sc))
848finalise (App f a) = App (finalise f) (finalise a)
849finalise t = t
851-- Once we've finished checking everything about a term we no longer need
852-- the type on the 'P' so erase it so save memory
854pEraseType :: TT n -> TT n
855pEraseType (P nt t _) = P nt t Erased
856pEraseType (App f a) = App (pEraseType f) (pEraseType a)
857pEraseType (Bind n b sc) = Bind n (fmap pEraseType b) (pEraseType sc)
858pEraseType t = t
860-- | As 'instantiate', but in addition to replacing @'V' 0@,
861-- replace references to the given 'Name'-like id.
862subst :: Eq n => n {-^ The id to replace -} ->
863 TT n {-^ The replacement term -} ->
864 TT n {-^ The term to replace in -} ->
865 TT n
866subst n v tm = instantiate v (pToV n tm)
868-- If there are no Vs in the term (i.e. in proof state)
869psubst :: Eq n => n -> TT n -> TT n -> TT n
870psubst n v tm = s' tm where
871 s' (P _ x _) | n == x = v
872 s' (Bind x b sc) | n == x = Bind x (fmap s' b) sc
873 | otherwise = Bind x (fmap s' b) (s' sc)
874 s' (App f a) = App (s' f) (s' a)
875 s' (Proj t idx) = Proj (s' t) idx
876 s' t = t
878-- | As 'subst', but takes a list of (name, substitution) pairs instead
879-- of a single name and substitution
880substNames :: Eq n => [(n, TT n)] -> TT n -> TT n
881substNames [] t = t
882substNames ((n, tm) : xs) t = subst n tm (substNames xs t)
884-- | Replaces all terms equal (in the sense of @(==)@) to
885-- the old term with the new term.
886substTerm :: Eq n => TT n {-^ Old term -} ->
887 TT n {-^ New term -} ->
888 TT n {-^ template term -}
889 -> TT n
890substTerm old new = st where
891 st t | t == old = new
892 st (App f a) = App (st f) (st a)
893 st (Bind x b sc) = Bind x (fmap st b) (st sc)
894 st t = t
896-- | Returns true if V 0 and bound name n do not occur in the term
897noOccurrence :: Eq n => n -> TT n -> Bool
898noOccurrence n t = no' 0 t
899 where
900 no' i (V x) = not (i == x)
901 no' i (P Bound x _) = not (n == x)
902 no' i (Bind n b sc) = noB' i b && no' (i+1) sc
903 where noB' i (Let t v) = no' i t && no' i v
904 noB' i (Guess t v) = no' i t && no' i v
905 noB' i b = no' i (binderTy b)
906 no' i (App f a) = no' i f && no' i a
907 no' i (Proj x _) = no' i x
908 no' i _ = True
910-- | Returns all names used free in the term
911freeNames :: Eq n => TT n -> [n]
912freeNames (P _ n _) = [n]
913freeNames (Bind n (Let t v) sc) = nub $ freeNames v ++ (freeNames sc \\ [n])
914 ++ freeNames t
915freeNames (Bind n b sc) = nub $ freeNames (binderTy b) ++ (freeNames sc \\ [n])
916freeNames (App f a) = nub $ freeNames f ++ freeNames a
917freeNames (Proj x i) = nub $ freeNames x
918freeNames _ = []
920-- | Return the arity of a (normalised) type
921arity :: TT n -> Int
922arity (Bind n (Pi t) sc) = 1 + arity sc
923arity _ = 0
925-- | Deconstruct an application; returns the function and a list of arguments
926unApply :: TT n -> (TT n, [TT n])
927unApply t = ua [] t where
928 ua args (App f a) = ua (a:args) f
929 ua args t = (t, args)
931-- | Returns a term representing the application of the first argument
932-- (a function) to every element of the second argument.
933mkApp :: TT n -> [TT n] -> TT n
934mkApp f [] = f
935mkApp f (a:as) = mkApp (App f a) as
937unList :: Term -> Maybe [Term]
938unList tm = case unApply tm of
939 (nil, [_]) -> Just []
940 (cons, ([_, x, xs])) ->
941 do rest <- unList xs
942 return $ x:rest
943 (f, args) -> Nothing
945-- | Cast a 'TT' term to a 'Raw' value, discarding universe information and
946-- the types of named references and replacing all de Bruijn indices
947-- with the corresponding name. It is an error if there are free de
948-- Bruijn indices.
949forget :: TT Name -> Raw
950forget tm = fe [] tm
951 where
952 fe env (P _ n _) = Var n
953 fe env (V i) = Var (env !! i)
954 fe env (Bind n b sc) = let n' = uniqueName n env in
955 RBind n' (fmap (fe env) b)
956 (fe (n':env) sc)
957 fe env (App f a) = RApp (fe env f) (fe env a)
958 fe env (Constant c)
959 = RConstant c
960 fe env (TType i) = RType
961 fe env Erased = RConstant Forgot
963-- | Introduce a 'Bind' into the given term for each element of the
964-- given list of (name, binder) pairs.
965bindAll :: [(n, Binder (TT n))] -> TT n -> TT n
966bindAll [] t = t
967bindAll ((n, b) : bs) t = Bind n b (bindAll bs t)
969-- | Like 'bindAll', but the 'Binder's are 'TT' terms instead.
970-- The first argument is a function to map @TT@ terms to @Binder@s.
971-- This function might often be something like 'Lam', which directly
972-- constructs a @Binder@ from a @TT@ term.
973bindTyArgs :: (TT n -> Binder (TT n)) -> [(n, TT n)] -> TT n -> TT n
974bindTyArgs b xs = bindAll (map (\ (n, ty) -> (n, b ty)) xs)
976-- | Return a list of pairs of the names of the outermost 'Pi'-bound
977-- variables in the given term, together with their types.
978getArgTys :: TT n -> [(n, TT n)]
979getArgTys (Bind n (Pi t) sc) = (n, t) : getArgTys sc
980getArgTys _ = []
982getRetTy :: TT n -> TT n
983getRetTy (Bind n (PVar _) sc) = getRetTy sc
984getRetTy (Bind n (PVTy _) sc) = getRetTy sc
985getRetTy (Bind n (Pi _) sc) = getRetTy sc
986getRetTy sc = sc
988uniqueNameFrom :: [Name] -> [Name] -> Name
989uniqueNameFrom (s : supply) hs
990 | s `elem` hs = uniqueNameFrom supply hs
991 | otherwise = s
993uniqueName :: Name -> [Name] -> Name
994uniqueName n hs | n `elem` hs = uniqueName (nextName n) hs
995 | otherwise = n
997uniqueBinders :: [Name] -> TT Name -> TT Name
998uniqueBinders ns (Bind n b sc)
999 = let n' = uniqueName n ns in
1000 Bind n' (fmap (uniqueBinders (n':ns)) b) (uniqueBinders ns sc)
1001uniqueBinders ns (App f a) = App (uniqueBinders ns f) (uniqueBinders ns a)
1002uniqueBinders ns t = t
1005nextName (NS x s) = NS (nextName x) s
1006nextName (MN i n) = MN (i+1) n
1007nextName (UN x) = let (num', nm') = T.span isDigit (T.reverse x)
1008 nm = T.reverse nm'
1009 num = readN (T.reverse num') in
1010 UN (nm `T.append` txt (show (num+1)))
1011 where
1012 readN x | not (T.null x) = read (T.unpack x)
1013 readN x = 0
1014nextName (SN x) = SN (nextName' x)
1015 where
1016 nextName' (WhereN i f x) = WhereN i f (nextName x)
1017 nextName' (CaseN n) = CaseN (nextName n)
1018 nextName' (MethodN n) = MethodN (nextName n)
1020type Term = TT Name
1021type Type = Term
1023type Env = EnvTT Name
1025-- | an environment with de Bruijn indices 'normalised' so that they all refer to
1026-- this environment
1028newtype WkEnvTT n = Wk (EnvTT n)
1029type WkEnv = WkEnvTT Name
1031instance (Eq n, Show n) => Show (TT n) where
1032 show t = showEnv [] t
1034itBitsName IT8 = "Bits8"
1035itBitsName IT16 = "Bits16"
1036itBitsName IT32 = "Bits32"
1037itBitsName IT64 = "Bits64"
1039instance Show Const where
1040 show (I i) = show i
1041 show (BI i) = show i
1042 show (Fl f) = show f
1043 show (Ch c) = show c
1044 show (Str s) = show s
1045 show (B8 x) = show x
1046 show (B16 x) = show x
1047 show (B32 x) = show x
1048 show (B64 x) = show x
1049 show (B8V x) = "<" ++ intercalate "," (map show (V.toList x)) ++ ">"
1050 show (B16V x) = "<" ++ intercalate "," (map show (V.toList x)) ++ ">"
1051 show (B32V x) = "<" ++ intercalate "," (map show (V.toList x)) ++ ">"
1052 show (B64V x) = "<" ++ intercalate "," (map show (V.toList x)) ++ ">"
1053 show (AType ATFloat) = "Float"
1054 show (AType (ATInt ITBig)) = "Integer"
1055 show (AType (ATInt ITNative)) = "Int"
1056 show (AType (ATInt ITChar)) = "Char"
1057 show (AType (ATInt (ITFixed it))) = itBitsName it
1058 show (AType (ATInt (ITVec it c))) = itBitsName it ++ "x" ++ show c
1059 show StrType = "String"
1060 show BufferType = "prim__UnsafeBuffer"
1061 show PtrType = "Ptr"
1062 show ManagedPtrType = "ManagedPtr"
1063 show VoidType = "Void"
1065showEnv :: (Eq n, Show n) => EnvTT n -> TT n -> String
1066showEnv env t = showEnv' env t False
1067showEnvDbg env t = showEnv' env t True
1069prettyEnv env t = prettyEnv' env t False
1070 where
1071 prettyEnv' env t dbg = prettySe 10 env t dbg
1073 bracket outer inner p
1074 | inner > outer = lparen <> p <> rparen
1075 | otherwise = p
1077 prettySe p env (P nt n t) debug =
1078 pretty n <+>
1079 if debug then
1080 lbracket <+> pretty nt <+> colon <+> prettySe 10 env t debug <+> rbracket
1081 else
1082 empty
1083 prettySe p env (V i) debug
1084 | i < length env =
1085 if debug then
1086 text . show . fst $ env!!i
1087 else
1088 lbracket <+> text (show i) <+> rbracket
1089 | otherwise = text "unbound" <+> text (show i) <+> text "!"
1090 prettySe p env (Bind n b@(Pi t) sc) debug
1091 | noOccurrence n sc && not debug =
1092 bracket p 2 $ prettySb env n b debug <> prettySe 10 ((n, b):env) sc debug
1093 prettySe p env (Bind n b sc) debug =
1094 bracket p 2 $ prettySb env n b debug <> prettySe 10 ((n, b):env) sc debug
1095 prettySe p env (App f a) debug =
1096 bracket p 1 $ prettySe 1 env f debug <+> prettySe 0 env a debug
1097 prettySe p env (Proj x i) debug =
1098 prettySe 1 env x debug <+> text ("!" ++ show i)
1099 prettySe p env (Constant c) debug = pretty c
1100 prettySe p env Erased debug = text "[_]"
1101 prettySe p env (TType i) debug = text "Type" <+> (text . show $ i)
1103 -- Render a `Binder` and its name
1104 prettySb env n (Lam t) = prettyB env "λ" "=>" n t
1105 prettySb env n (Hole t) = prettyB env "?defer" "." n t
1106 prettySb env n (Pi t) = prettyB env "(" ") ->" n t
1107 prettySb env n (PVar t) = prettyB env "pat" "." n t
1108 prettySb env n (PVTy t) = prettyB env "pty" "." n t
1109 prettySb env n (Let t v) = prettyBv env "let" "in" n t v
1110 prettySb env n (Guess t v) = prettyBv env "??" "in" n t v
1112 -- Use `op` and `sc` to delimit `n` (a binding name) and its type
1113 -- declaration
1114 -- e.g. "λx : Int =>" for the Lam case
1115 prettyB env op sc n t debug =
1116 text op <> pretty n <+> colon <+> prettySe 10 env t debug <> text sc
1118 -- Like `prettyB`, but handle the bindings that have values in addition
1119 -- to names and types
1120 prettyBv env op sc n t v debug =
1121 text op <> pretty n <+> colon <+> prettySe 10 env t debug <+> text "=" <+>
1122 prettySe 10 env v debug <> text sc
1125showEnv' env t dbg = se 10 env t where
1126 se p env (P nt n t) = show n
1127 ++ if dbg then "{" ++ show nt ++ " : " ++ se 10 env t ++ "}" else ""
1128 se p env (V i) | i < length env && i >= 0
1129 = (show $ fst $ env!!i) ++
1130 if dbg then "{" ++ show i ++ "}" else ""
1131 | otherwise = "!!V " ++ show i ++ "!!"
1132 se p env (Bind n b@(Pi t) sc)
1133 | noOccurrence n sc && not dbg = bracket p 2 $ se 1 env t ++ " -> " ++ se 10 ((n,b):env) sc
1134 se p env (Bind n b sc) = bracket p 2 $ sb env n b ++ se 10 ((n,b):env) sc
1135 se p env (App f a) = bracket p 1 $ se 1 env f ++ " " ++ se 0 env a
1136 se p env (Proj x i) = se 1 env x ++ "!" ++ show i
1137 se p env (Constant c) = show c
1138 se p env Erased = "[__]"
1139 se p env Impossible = "[impossible]"
1140 se p env (TType i) = "Type " ++ show i
1142 sb env n (Lam t) = showb env "\\ " " => " n t
1143 sb env n (Hole t) = showb env "? " ". " n t
1144 sb env n (GHole i t) = showb env "?defer " ". " n t
1145 sb env n (Pi t) = showb env "(" ") -> " n t
1146 sb env n (PVar t) = showb env "pat " ". " n t
1147 sb env n (PVTy t) = showb env "pty " ". " n t
1148 sb env n (Let t v) = showbv env "let " " in " n t v
1149 sb env n (Guess t v) = showbv env "?? " " in " n t v
1151 showb env op sc n t = op ++ show n ++ " : " ++ se 10 env t ++ sc
1152 showbv env op sc n t v = op ++ show n ++ " : " ++ se 10 env t ++ " = " ++
1153 se 10 env v ++ sc
1155 bracket outer inner str | inner > outer = "(" ++ str ++ ")"
1156 | otherwise = str
1158-- | Check whether a term has any holes in it - impure if so
1159pureTerm :: TT Name -> Bool
1160pureTerm (App f a) = pureTerm f && pureTerm a
1161pureTerm (Bind n b sc) = notClassName n && pureBinder b && pureTerm sc where
1162 pureBinder (Hole _) = False
1163 pureBinder (Guess _ _) = False
1164 pureBinder (Let t v) = pureTerm t && pureTerm v
1165 pureBinder t = pureTerm (binderTy t)
1167 notClassName (MN _ c) | c == txt "class" = False
1168 notClassName _ = True
1170pureTerm _ = True
1172-- | Weaken a term by adding i to each de Bruijn index (i.e. lift it over i bindings)
1173weakenTm :: Int -> TT n -> TT n
1174weakenTm i t = wk i 0 t
1175 where wk i min (V x) | x >= min = V (i + x)
1176 wk i m (App f a) = App (wk i m f) (wk i m a)
1177 wk i m (Bind x b sc) = Bind x (wkb i m b) (wk i (m + 1) sc)
1178 wk i m t = t
1179 wkb i m t = fmap (wk i m) t
1181-- | Weaken an environment so that all the de Bruijn indices are correct according
1182-- to the latest bound variable
1184weakenEnv :: EnvTT n -> EnvTT n
1185weakenEnv env = wk (length env - 1) env
1186 where wk i [] = []
1187 wk i ((n, b) : bs) = (n, weakenTmB i b) : wk (i - 1) bs
1188 weakenTmB i (Let t v) = Let (weakenTm i t) (weakenTm i v)
1189 weakenTmB i (Guess t v) = Guess (weakenTm i t) (weakenTm i v)
1190 weakenTmB i t = t { binderTy = weakenTm i (binderTy t) }
1192-- | Weaken every term in the environment by the given amount
1193weakenTmEnv :: Int -> EnvTT n -> EnvTT n
1194weakenTmEnv i = map (\ (n, b) -> (n, fmap (weakenTm i) b))
1196-- | Gather up all the outer 'PVar's and 'Hole's in an expression and reintroduce
1197-- them in a canonical order
1198orderPats :: Term -> Term
1199orderPats tm = op [] tm
1200 where
1201 op ps (Bind n (PVar t) sc) = op ((n, PVar t) : ps) sc
1202 op ps (Bind n (Hole t) sc) = op ((n, Hole t) : ps) sc
1203 op ps sc = bindAll (sortP ps) sc
1205 sortP ps = pick [] (reverse ps)
1207 namesIn (P _ n _) = [n]
1208 namesIn (Bind n b t) = nub $ nb b ++ (namesIn t \\ [n])
1209 where nb (Let t v) = nub (namesIn t) ++ nub (namesIn v)
1210 nb (Guess t v) = nub (namesIn t) ++ nub (namesIn v)
1211 nb t = namesIn (binderTy t)
1212 namesIn (App f a) = nub (namesIn f ++ namesIn a)
1213 namesIn _ = []
1215 pick acc [] = reverse acc
1216 pick acc ((n, t) : ps) = pick (insert n t acc) ps
1218 insert n t [] = [(n, t)]
1219 insert n t ((n',t') : ps)
1220 | n `elem` (namesIn (binderTy t') ++
1221 concatMap namesIn (map (binderTy . snd) ps))
1222 = (n', t') : insert n t ps
1223 | otherwise = (n,t):(n',t'):ps