-- | Sanity checking for internal syntax. Mostly checking variable scoping.
module Agda.Syntax.Internal.SanityCheck where

import Control.Monad
import qualified Data.IntSet as Set

import Agda.Syntax.Internal
import Agda.TypeChecking.Free
import Agda.TypeChecking.Monad

import Agda.Utils.List ( dropEnd, initWithDefault )
import Agda.Utils.Pretty
import Agda.Utils.Size
import Agda.Utils.Impossible


sanityCheckVars :: (Pretty a, Free a) => Telescope -> a -> TCM ()
sanityCheckVars :: forall a. (Pretty a, Free a) => Telescope -> a -> TCM ()
sanityCheckVars Telescope
tel a
v =
  case (Int -> Bool) -> [Int] -> [Int]
forall a. (a -> Bool) -> [a] -> [a]
filter Int -> Bool
bad (IntSet -> [Int]
Set.toList (IntSet -> [Int]) -> IntSet -> [Int]
forall a b. (a -> b) -> a -> b
$ a -> IntSet
forall t. Free t => t -> IntSet
allFreeVars a
v) of
    [] -> () -> TCM ()
forall a. a -> TCMT IO a
forall (m :: * -> *) a. Monad m => a -> m a
return ()
    [Int]
xs -> do
      [Char] -> Int -> TCM Doc -> TCM ()
forall (m :: * -> *).
MonadDebug m =>
[Char] -> Int -> TCM Doc -> m ()
reportSDoc [Char]
"impossible" Int
1 (TCM Doc -> TCM ()) -> (Doc -> TCM Doc) -> Doc -> TCM ()
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Doc -> TCM Doc
forall a. a -> TCMT IO a
forall (m :: * -> *) a. Monad m => a -> m a
return (Doc -> TCM ()) -> Doc -> TCM ()
forall a b. (a -> b) -> a -> b
$
        [Doc] -> Doc
forall (t :: * -> *). Foldable t => t Doc -> Doc
sep [ Doc -> Int -> Doc -> Doc
hang Doc
"Sanity check failed for" Int
2
                   (Doc -> Int -> Doc -> Doc
hang (Telescope -> Doc
forall a. Pretty a => a -> Doc
pretty Telescope
tel Doc -> Doc -> Doc
<+> Doc
"|-") Int
2 (a -> Doc
forall a. Pretty a => a -> Doc
pretty a
v))
            , [Char] -> Doc
text ([Char] -> Doc) -> [Char] -> Doc
forall a b. (a -> b) -> a -> b
$ [Char]
"out of scope: " [Char] -> [Char] -> [Char]
forall a. [a] -> [a] -> [a]
++ [Int] -> [Char]
forall a. Show a => a -> [Char]
show [Int]
xs ]
      TCM ()
forall a. HasCallStack => a
__IMPOSSIBLE__
  where
    n :: Int
n     = Telescope -> Int
forall a. Sized a => a -> Int
size Telescope
tel
    bad :: Int -> Bool
bad Int
x = Int
x Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
< Int
0 Bool -> Bool -> Bool
|| Int
x Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
>= Int
n

-- | Check that @Γ ⊢ ρ : Δ@.
sanityCheckSubst :: (Pretty a, Free a) => Telescope -> Substitution' a -> Telescope -> TCM ()
sanityCheckSubst :: forall a.
(Pretty a, Free a) =>
Telescope -> Substitution' a -> Telescope -> TCM ()
sanityCheckSubst Telescope
gamma Substitution' a
rho Telescope
delta = Telescope -> Substitution' a -> Telescope -> TCM ()
go Telescope
gamma Substitution' a
rho Telescope
delta
  where
    go :: Telescope -> Substitution' a -> Telescope -> TCM ()
go Telescope
gamma Substitution' a
rho Telescope
delta =
      case Substitution' a
rho of
        Substitution' a
IdS      -> Bool -> TCM () -> TCM ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless (Telescope -> Int
forall a. Sized a => a -> Int
size Telescope
gamma Int -> Int -> Bool
forall a. Eq a => a -> a -> Bool
== Telescope -> Int
forall a. Sized a => a -> Int
size Telescope
delta) (TCM () -> TCM ()) -> TCM () -> TCM ()
forall a b. (a -> b) -> a -> b
$ Doc -> TCM ()
err (Doc -> TCM ()) -> Doc -> TCM ()
forall a b. (a -> b) -> a -> b
$ Doc
"idS:" Doc -> Doc -> Doc
<+> Doc -> Int -> Doc -> Doc
hang (Telescope -> Doc
forall a. Pretty a => a -> Doc
pretty Telescope
gamma Doc -> Doc -> Doc
<+> Doc
"/=") Int
2 (Telescope -> Doc
forall a. Pretty a => a -> Doc
pretty Telescope
delta)
        EmptyS Impossible
_ -> Bool -> TCM () -> TCM ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless (Telescope -> Int
forall a. Sized a => a -> Int
size Telescope
delta Int -> Int -> Bool
forall a. Eq a => a -> a -> Bool
== Int
0) (TCM () -> TCM ()) -> TCM () -> TCM ()
forall a b. (a -> b) -> a -> b
$ Doc -> TCM ()
err (Doc -> TCM ()) -> Doc -> TCM ()
forall a b. (a -> b) -> a -> b
$ Doc
"emptyS:" Doc -> Doc -> Doc
<+> Telescope -> Doc
forall a. Pretty a => a -> Doc
pretty Telescope
delta Doc -> Doc -> Doc
<+> Doc
"is not empty"
        a
v :# Substitution' a
rho -> do
          Bool -> TCM () -> TCM ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless (Telescope -> Int
forall a. Sized a => a -> Int
size Telescope
delta Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
> Int
0) (TCM () -> TCM ()) -> TCM () -> TCM ()
forall a b. (a -> b) -> a -> b
$ Doc -> TCM ()
err (Doc -> TCM ()) -> Doc -> TCM ()
forall a b. (a -> b) -> a -> b
$ Doc
"consS: empty target"
          Telescope -> a -> TCM ()
forall a. (Pretty a, Free a) => Telescope -> a -> TCM ()
sanityCheckVars Telescope
gamma a
v
          Telescope -> Substitution' a -> Telescope -> TCM ()
forall a.
(Pretty a, Free a) =>
Telescope -> Substitution' a -> Telescope -> TCM ()
sanityCheckSubst Telescope
gamma Substitution' a
rho (Telescope -> Telescope
dropLast Telescope
delta)
        Strengthen Impossible
_ Int
n Substitution' a
rho -> do
          Bool -> TCM () -> TCM ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless (Telescope -> Int
forall a. Sized a => a -> Int
size Telescope
delta Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
>= Int
n) (TCM () -> TCM ()) -> TCM () -> TCM ()
forall a b. (a -> b) -> a -> b
$ Doc -> TCM ()
err (Doc -> TCM ()) -> Doc -> TCM ()
forall a b. (a -> b) -> a -> b
$ Doc
"strS: empty target"
          Telescope -> Substitution' a -> Telescope -> TCM ()
forall a.
(Pretty a, Free a) =>
Telescope -> Substitution' a -> Telescope -> TCM ()
sanityCheckSubst Telescope
gamma Substitution' a
rho (Int -> Telescope -> Telescope
dropLastN Int
n Telescope
delta)
        Wk Int
n Substitution' a
rho -> do
          Bool -> TCM () -> TCM ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless (Telescope -> Int
forall a. Sized a => a -> Int
size Telescope
gamma Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
>= Int
n) (TCM () -> TCM ()) -> TCM () -> TCM ()
forall a b. (a -> b) -> a -> b
$ Doc -> TCM ()
err (Doc -> TCM ()) -> Doc -> TCM ()
forall a b. (a -> b) -> a -> b
$ Doc
"wkS:" Doc -> Doc -> Doc
<+> [Doc] -> Doc
forall (t :: * -> *). Foldable t => t Doc -> Doc
sep [ Doc
"|" Doc -> Doc -> Doc
forall a. Semigroup a => a -> a -> a
<> Telescope -> Doc
forall a. Pretty a => a -> Doc
pretty Telescope
gamma Doc -> Doc -> Doc
forall a. Semigroup a => a -> a -> a
<> Doc
"|"
                                                               , [Char] -> Doc
text ([Char] -> Doc) -> [Char] -> Doc
forall a b. (a -> b) -> a -> b
$ [Char]
"< " [Char] -> [Char] -> [Char]
forall a. [a] -> [a] -> [a]
++ Int -> [Char]
forall a. Show a => a -> [Char]
show Int
n ]
          Telescope -> Substitution' a -> Telescope -> TCM ()
forall a.
(Pretty a, Free a) =>
Telescope -> Substitution' a -> Telescope -> TCM ()
sanityCheckSubst (Int -> Telescope -> Telescope
dropLastN Int
n Telescope
gamma) Substitution' a
rho Telescope
delta
        Lift Int
n Substitution' a
rho -> do
          Bool -> TCM () -> TCM ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless (Telescope -> Int
forall a. Sized a => a -> Int
size Telescope
gamma Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
>= Int
n) (TCM () -> TCM ()) -> TCM () -> TCM ()
forall a b. (a -> b) -> a -> b
$ Doc -> TCM ()
err (Doc -> TCM ()) -> Doc -> TCM ()
forall a b. (a -> b) -> a -> b
$ Doc
"liftS: source" Doc -> Doc -> Doc
<+> [Doc] -> Doc
forall (t :: * -> *). Foldable t => t Doc -> Doc
sep [ Doc
"|" Doc -> Doc -> Doc
forall a. Semigroup a => a -> a -> a
<> Telescope -> Doc
forall a. Pretty a => a -> Doc
pretty Telescope
gamma Doc -> Doc -> Doc
forall a. Semigroup a => a -> a -> a
<> Doc
"|"
                                                                        , [Char] -> Doc
text ([Char] -> Doc) -> [Char] -> Doc
forall a b. (a -> b) -> a -> b
$ [Char]
"< " [Char] -> [Char] -> [Char]
forall a. [a] -> [a] -> [a]
++ Int -> [Char]
forall a. Show a => a -> [Char]
show Int
n ]
          Bool -> TCM () -> TCM ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless (Telescope -> Int
forall a. Sized a => a -> Int
size Telescope
delta Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
>= Int
n) (TCM () -> TCM ()) -> TCM () -> TCM ()
forall a b. (a -> b) -> a -> b
$ Doc -> TCM ()
err (Doc -> TCM ()) -> Doc -> TCM ()
forall a b. (a -> b) -> a -> b
$ Doc
"liftS: target" Doc -> Doc -> Doc
<+> [Doc] -> Doc
forall (t :: * -> *). Foldable t => t Doc -> Doc
sep [ Doc
"|" Doc -> Doc -> Doc
forall a. Semigroup a => a -> a -> a
<> Telescope -> Doc
forall a. Pretty a => a -> Doc
pretty Telescope
delta Doc -> Doc -> Doc
forall a. Semigroup a => a -> a -> a
<> Doc
"|"
                                                                        , [Char] -> Doc
text ([Char] -> Doc) -> [Char] -> Doc
forall a b. (a -> b) -> a -> b
$ [Char]
"< " [Char] -> [Char] -> [Char]
forall a. [a] -> [a] -> [a]
++ Int -> [Char]
forall a. Show a => a -> [Char]
show Int
n ]
          Telescope -> Substitution' a -> Telescope -> TCM ()
forall a.
(Pretty a, Free a) =>
Telescope -> Substitution' a -> Telescope -> TCM ()
sanityCheckSubst (Int -> Telescope -> Telescope
dropLastN Int
n Telescope
gamma) Substitution' a
rho (Int -> Telescope -> Telescope
dropLastN Int
n Telescope
delta)

    dropLast :: Telescope -> Telescope
dropLast = ListTel -> Telescope
telFromList (ListTel -> Telescope)
-> (Telescope -> ListTel) -> Telescope -> Telescope
forall b c a. (b -> c) -> (a -> b) -> a -> c
. ListTel -> ListTel -> ListTel
forall a. [a] -> [a] -> [a]
initWithDefault ListTel
forall a. HasCallStack => a
__IMPOSSIBLE__ (ListTel -> ListTel)
-> (Telescope -> ListTel) -> Telescope -> ListTel
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Telescope -> ListTel
forall t. Tele (Dom t) -> [Dom ([Char], t)]
telToList
    dropLastN :: Int -> Telescope -> Telescope
dropLastN Int
n = ListTel -> Telescope
telFromList (ListTel -> Telescope)
-> (Telescope -> ListTel) -> Telescope -> Telescope
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Int -> ListTel -> ListTel
forall a. Int -> [a] -> [a]
dropEnd Int
n (ListTel -> ListTel)
-> (Telescope -> ListTel) -> Telescope -> ListTel
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Telescope -> ListTel
forall t. Tele (Dom t) -> [Dom ([Char], t)]
telToList

    err :: Doc -> TCM ()
err Doc
reason = do
      [Char] -> Int -> TCM Doc -> TCM ()
forall (m :: * -> *).
MonadDebug m =>
[Char] -> Int -> TCM Doc -> m ()
reportSDoc [Char]
"impossible" Int
1 (TCM Doc -> TCM ()) -> (Doc -> TCM Doc) -> Doc -> TCM ()
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Doc -> TCM Doc
forall a. a -> TCMT IO a
forall (m :: * -> *) a. Monad m => a -> m a
return (Doc -> TCM ()) -> Doc -> TCM ()
forall a b. (a -> b) -> a -> b
$
        [Doc] -> Doc
forall (t :: * -> *). Foldable t => t Doc -> Doc
sep [ Doc -> Int -> Doc -> Doc
hang Doc
"Sanity check failed for" Int
2 (Doc -> Doc) -> Doc -> Doc
forall a b. (a -> b) -> a -> b
$
              Doc -> Int -> Doc -> Doc
hang (Telescope -> Doc
forall a. Pretty a => a -> Doc
pretty Telescope
gamma Doc -> Doc -> Doc
<+> Doc
"|-") Int
2 (Doc -> Doc) -> Doc -> Doc
forall a b. (a -> b) -> a -> b
$
              Doc -> Int -> Doc -> Doc
hang (Substitution' a -> Doc
forall a. Pretty a => a -> Doc
pretty Substitution' a
rho Doc -> Doc -> Doc
<+> Doc
":") Int
2 (Doc -> Doc) -> Doc -> Doc
forall a b. (a -> b) -> a -> b
$
                    Telescope -> Doc
forall a. Pretty a => a -> Doc
pretty Telescope
delta
            , Doc
reason ]
      TCM ()
forall a. HasCallStack => a
__IMPOSSIBLE__