From e72192c0c1825f36f054263437029d05d717c957 Mon Sep 17 00:00:00 2001 From: NanoTech Date: Thu, 8 Dec 2016 03:12:38 -0600 Subject: Begin implementing type checking --- src/typecheck.rs | 621 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 621 insertions(+) create mode 100644 src/typecheck.rs (limited to 'src/typecheck.rs') diff --git a/src/typecheck.rs b/src/typecheck.rs new file mode 100644 index 0000000..e552de5 --- /dev/null +++ b/src/typecheck.rs @@ -0,0 +1,621 @@ +#![allow(non_snake_case)] +use std::collections::HashSet; + +use context::Context; +use core; +use core::{Expr, V, X, bx, normalize, shift, subst}; +use core::{pi, app}; +use core::Expr::*; +use core::Const::*; + +use self::TypeMessage::*; + +fn axiom<'i, S: Clone>(c: core::Const) -> Result> { + match c { + Type => Ok(Kind), + Kind => Err(TypeError::new(&Context::new(), &Const(Kind), Untyped)), + } +} + +fn rule(a: core::Const, b: core::Const) -> Result { + match (a, b) { + (Type, Kind) => Err(()), + (Type, Type) => Ok(Type), + (Kind, Kind) => Ok(Kind), + (Kind, Type) => Ok(Type), + } +} + +fn match_vars(vl: &V, vr: &V, ctx: &[(&str, &str)]) -> bool { + let xxs = ctx.get(0).map(|x| (x, ctx.split_at(1).1)); + match (vl, vr, xxs) { + (&V(ref xL, nL), &V(ref xR, nR), None) => xL == xR && nL == nR, + (&V(ref xL, 0), &V(ref xR, 0), Some((&(ref xL2, ref xR2), _))) if xL == xL2 && xR == xR2 => true, + (&V(ref xL, nL), &V(ref xR, nR), Some((&(ref xL2, ref xR2), xs))) => { + let nL2 = if *xL == xL2.as_ref() { nL - 1 } else { nL }; + let nR2 = if *xR == xR2.as_ref() { nR - 1 } else { nR }; + match_vars(&V(xL.clone(), nL2), &V(xR.clone(), nR2), xs) + } + } +} + +fn prop_equal(eL0: &Expr, eR0: &Expr) -> bool + where S: Clone + ::std::fmt::Debug, + T: Clone + ::std::fmt::Debug +{ + fn go<'i, S, T>(ctx: &mut Vec<(&'i str, &'i str)>, el: &'i Expr<'i, S, X>, er: &'i Expr<'i, T, X>) -> bool + where S: Clone + ::std::fmt::Debug, + T: Clone + ::std::fmt::Debug + { + match (el, er) { + (&Const(Type), &Const(Type)) => true, + (&Const(Kind), &Const(Kind)) => true, + (&Var(ref vL), &Var(ref vR)) => match_vars(vL, vR, &*ctx), + (&Pi(ref xL, ref tL, ref bL), &Pi(ref xR, ref tR, ref bR)) => { + //ctx <- State.get + let eq1 = go(ctx, tL, tR); + if eq1 { + //State.put ((xL, xR):ctx) + ctx.push((xL, xR)); + let eq2 = go(ctx, bL, bR); + //State.put ctx + let _ = ctx.pop(); + eq2 + } else { + false + } + } + (&App(ref fL, ref aL), &App(ref fR, ref aR)) => + if go(ctx, fL, fR) { go(ctx, aL, aR) } else { false }, + (&Bool, &Bool) => true, + (&Natural, &Natural) => true, + (&Integer, &Integer) => true, + (&Double, &Double) => true, + (&Text, &Text) => true, + (&List, &List) => true, + (&Optional, &Optional) => true, + (&Record(ref _ktsL0), &Record(ref _ktsR0)) => unimplemented!(), + /* + let loop ((kL, tL):ktsL) ((kR, tR):ktsR) + | kL == kR = do + b <- go tL tR + if b + then loop ktsL ktsR + else return False + loop [] [] = return True + loop _ _ = return False + loop (Data.Map.toList ktsL0) (Data.Map.toList ktsR0) + */ + (&Union(ref _ktsL0), &Union(ref _ktsR0)) => unimplemented!(), + /* + let loop ((kL, tL):ktsL) ((kR, tR):ktsR) + | kL == kR = do + b <- go tL tR + if b + then loop ktsL ktsR + else return False + loop [] [] = return True + loop _ _ = return False + loop (Data.Map.toList ktsL0) (Data.Map.toList ktsR0) + */ + (_, _) => false, + } + } + let mut ctx = vec![]; + go::(&mut ctx, &normalize(eL0.clone()), &normalize(eR0.clone())) +} + + +/// Type-check an expression and return the expression'i type if type-checking +/// suceeds or an error if type-checking fails +/// +/// `type_with` does not necessarily normalize the type since full normalization +/// is not necessary for just type-checking. If you actually care about the +/// returned type then you may want to `normalize` it afterwards. +pub fn type_with<'i, S>(ctx: &Context<'i, Expr<'i, S, X>>, + e: &Expr<'i, S, X>) + -> Result, TypeError<'i, S>> + where S: Clone + ::std::fmt::Debug + 'i +{ + match e { + &Const(c) => axiom(c).map(Const), //.map(Cow::Owned), + &Var(V(ref x, n)) => { + ctx.lookup(x, n) + .cloned() + //.map(Cow::Borrowed) + .ok_or_else(|| TypeError::new(ctx, &e, UnboundVariable)) + } + &Lam(ref x, ref tA, ref b) => { + let ctx2 = ctx.insert(x.clone(), (**tA).clone()).map(|e| core::shift(1, V(x.clone(), 0), e.clone())); + let tB = type_with(&ctx2, b)?; + let p = Pi(x.clone(), tA.clone(), bx(tB)); + let _ = type_with(ctx, &p)?; + //Ok(Cow::Owned(p)) + Ok(p) + } + &Pi(ref x, ref tA, ref tB) => { + let tA2 = normalize::(type_with(ctx, tA)?); + let kA = match tA2 { + Const(k) => k, + _ => return Err(TypeError::new(ctx, e, InvalidInputType((**tA).clone()))), + }; + + let ctx2 = ctx.insert(x.clone(), (**tA).clone()).map(|e| core::shift(1, V(x.clone(), 0), e.clone())); + let tB = normalize(type_with(&ctx2, tB)?); + let kB = match tB { + Const(k) => k, + _ => return Err(TypeError::new(&ctx2, e, InvalidOutputType(tB))), + }; + + match rule(kA, kB) { + Err(()) => Err(TypeError::new(ctx, e, NoDependentTypes((**tA).clone(), tB))), + Ok(k) => Ok(Const(k)), + } + } + &App(ref f, ref a) => { + let tf = normalize(type_with(ctx, f)?); + let (x, tA, tB) = match tf { + Pi(x, tA, tB) => (x, tA, tB), + _ => return Err(TypeError::new(ctx, e, NotAFunction((**f).clone(), tf))), + }; + let tA2 = type_with(ctx, a)?; + if prop_equal(&tA, &tA2) { + let vx0 = V(x, 0); + let a2 = shift::( 1, vx0.clone(), (**a).clone()); + let tB2 = subst(vx0.clone(), a2, (*tB).clone()); + let tB3 = shift::(-1, vx0, tB2); + Ok(tB3) + } else { + let nf_A = normalize(*tA); + let nf_A2 = normalize(tA2); + Err(TypeError::new(ctx, e, TypeMismatch((**f).clone(), nf_A, (**a).clone(), nf_A2))) + } + } + &Let(ref f, ref mt, ref r, ref b) => { + let tR = type_with(ctx, r)?; + let ttR = normalize::(type_with(ctx, &tR)?); + let kR = match ttR { + Const(k) => k, + // Don't bother to provide a `let`-specific version of this error + // message because this should never happen anyway + _ => return Err(TypeError::new(ctx, &e, InvalidInputType(tR))), + }; + + let ctx2 = ctx.insert(f.clone(), tR.clone()); + let tB = type_with(&ctx2, b)?; + let ttB = normalize::(type_with(ctx, &tB)?); + let kB = match ttB { + Const(k) => k, + // Don't bother to provide a `let`-specific version of this error + // message because this should never happen anyway + _ => return Err(TypeError::new(ctx, &e, InvalidOutputType(tB))), + }; + + if let Err(()) = rule(kR, kB) { + return Err(TypeError::new(ctx, &e, NoDependentLet(tR, tB))); + } + + if let &Some(ref t) = mt { + let nf_t = normalize((**t).clone()); + let nf_tR = normalize(tR.clone()); + if !prop_equal(&nf_tR, &nf_t) { + return Err(TypeError::new(ctx, &e, AnnotMismatch((**r).clone(), nf_t, nf_tR))); + } + } + + Ok(tB) + } +/* +type_with ctx e@(Annot x t ) = do + -- This is mainly just to check that `t` is not `Kind` + _ <- type_with ctx t + + t' <- type_with ctx x + if prop_equal t t' + then do + return t + else do + let nf_t = Dhall.Core.normalize t + let nf_t' = Dhall.Core.normalize t' + Left (TypeError ctx e (AnnotMismatch x nf_t nf_t')) +*/ + &Bool => Ok(Const(Type)), + &BoolLit(_) => Ok(Bool), + &BoolAnd(ref l, ref r) => { + let tl = normalize(type_with(ctx, l)?); + match tl { + Bool => {} + _ => return Err(TypeError::new(ctx, e, CantAnd((**l).clone(), tl))), + } + + let tr = normalize(type_with(ctx, r)?); + match tr { + Bool => {} + _ => return Err(TypeError::new(ctx, e, CantAnd((**r).clone(), tr))), + } + + Ok(Bool) + } + /* +type_with ctx e@(BoolOr l r ) = do + tl <- fmap Dhall.Core.normalize (type_with ctx l) + case tl of + Bool -> return () + _ -> Left (TypeError ctx e (CantOr l tl)) + + tr <- fmap Dhall.Core.normalize (type_with ctx r) + case tr of + Bool -> return () + _ -> Left (TypeError ctx e (CantOr r tr)) + + return Bool +type_with ctx e@(BoolEQ l r ) = do + tl <- fmap Dhall.Core.normalize (type_with ctx l) + case tl of + Bool -> return () + _ -> Left (TypeError ctx e (CantEQ l tl)) + + tr <- fmap Dhall.Core.normalize (type_with ctx r) + case tr of + Bool -> return () + _ -> Left (TypeError ctx e (CantEQ r tr)) + + return Bool +type_with ctx e@(BoolNE l r ) = do + tl <- fmap Dhall.Core.normalize (type_with ctx l) + case tl of + Bool -> return () + _ -> Left (TypeError ctx e (CantNE l tl)) + + tr <- fmap Dhall.Core.normalize (type_with ctx r) + case tr of + Bool -> return () + _ -> Left (TypeError ctx e (CantNE r tr)) + + return Bool +type_with ctx e@(BoolIf x y z ) = do + tx <- fmap Dhall.Core.normalize (type_with ctx x) + case tx of + Bool -> return () + _ -> Left (TypeError ctx e (InvalidPredicate x tx)) + ty <- fmap Dhall.Core.normalize (type_with ctx y ) + tty <- fmap Dhall.Core.normalize (type_with ctx ty) + case tty of + Const Type -> return () + _ -> Left (TypeError ctx e (IfBranchMustBeTerm True y ty tty)) + + tz <- fmap Dhall.Core.normalize (type_with ctx z) + ttz <- fmap Dhall.Core.normalize (type_with ctx tz) + case ttz of + Const Type -> return () + _ -> Left (TypeError ctx e (IfBranchMustBeTerm False z tz ttz)) + + if prop_equal ty tz + then return () + else Left (TypeError ctx e (IfBranchMismatch y z ty tz)) + return ty + */ + &Natural => Ok(Const(Type)), + &NaturalLit(_) => Ok(Natural), + /* +type_with _ NaturalFold = do + return + (Pi "_" Natural + (Pi "natural" (Const Type) + (Pi "succ" (Pi "_" "natural" "natural") + (Pi "zero" "natural" "natural") ) ) ) +type_with _ NaturalBuild = do + return + (Pi "_" + (Pi "natural" (Const Type) + (Pi "succ" (Pi "_" "natural" "natural") + (Pi "zero" "natural" "natural") ) ) + Natural ) + */ + &NaturalIsZero => Ok(pi("_", Natural, Bool)), + &NaturalEven => Ok(pi("_", Natural, Bool)), + &NaturalOdd => Ok(pi("_", Natural, Bool)), + /* +type_with ctx e@(NaturalPlus l r) = do + tl <- fmap Dhall.Core.normalize (type_with ctx l) + case tl of + Natural -> return () + _ -> Left (TypeError ctx e (CantAdd l tl)) + + tr <- fmap Dhall.Core.normalize (type_with ctx r) + case tr of + Natural -> return () + _ -> Left (TypeError ctx e (CantAdd r tr)) + return Natural +type_with ctx e@(NaturalTimes l r) = do + tl <- fmap Dhall.Core.normalize (type_with ctx l) + case tl of + Natural -> return () + _ -> Left (TypeError ctx e (CantMultiply l tl)) + + tr <- fmap Dhall.Core.normalize (type_with ctx r) + case tr of + Natural -> return () + _ -> Left (TypeError ctx e (CantMultiply r tr)) + return Natural + */ + &Integer => Ok(Const(Type)), + &IntegerLit(_) => Ok(Integer), + &Double => Ok(Const(Type)), + &DoubleLit(_) => Ok(Double), + &Text => Ok(Const(Type)), + &TextLit(_) => Ok(Text), + /* +type_with ctx e@(TextAppend l r ) = do + tl <- fmap Dhall.Core.normalize (type_with ctx l) + case tl of + Text -> return () + _ -> Left (TypeError ctx e (CantTextAppend l tl)) + + tr <- fmap Dhall.Core.normalize (type_with ctx r) + case tr of + Text -> return () + _ -> Left (TypeError ctx e (CantTextAppend r tr)) + return Text + */ + &List => Ok(pi("_", Const(Type), Const(Type))), + /* +type_with ctx e@(ListLit t xs ) = do + s <- fmap Dhall.Core.normalize (type_with ctx t) + case s of + Const Type -> return () + _ -> Left (TypeError ctx e (InvalidListType t)) + flip Data.Vector.imapM_ xs (\i x -> do + t' <- type_with ctx x + if prop_equal t t' + then return () + else do + let nf_t = Dhall.Core.normalize t + let nf_t' = Dhall.Core.normalize t' + Left (TypeError ctx e (InvalidListElement i nf_t x nf_t')) ) + return (App List t) + */ + &ListBuild => + Ok(pi("a", Const(Type), + pi("_", + pi("list", Const(Type), + pi("cons", pi("_", "a", pi("_", "list", "list")), + pi("nil", "list", "list"))), + app(List, "a")))), + &ListFold => + Ok(pi("a", Const(Type), + pi("_", app(List, "a"), + pi("list", Const(Type), + pi("cons", pi("_", "a", pi("_", "list", "list")), + pi("nil", "list", "list")))))), + &ListLength => + Ok(pi("a", Const(Type), pi("_", app(List, "a"), Natural))), + &ListHead => + Ok(pi("a", Const(Type), pi("_", app(List, "a"), app(Optional, "a")))), + &ListLast => + Ok(pi("a", Const(Type), pi("_", app(List, "a"), app(Optional, "a")))), + /* +type_with _ ListIndexed = do + let kts = [("index", Natural), ("value", "a")] + return + (Pi "a" (Const Type) + (Pi "_" (App List "a") + (App List (Record (Data.Map.fromList kts))) ) ) +type_with _ ListReverse = do + return (Pi "a" (Const Type) (Pi "_" (App List "a") (App List "a"))) +type_with _ Optional = do + return (Pi "_" (Const Type) (Const Type)) +type_with ctx e@(OptionalLit t xs) = do + s <- fmap Dhall.Core.normalize (type_with ctx t) + case s of + Const Type -> return () + _ -> Left (TypeError ctx e (InvalidOptionalType t)) + let n = Data.Vector.length xs + if 2 <= n + then Left (TypeError ctx e (InvalidOptionalLiteral n)) + else return () + forM_ xs (\x -> do + t' <- type_with ctx x + if prop_equal t t' + then return () + else do + let nf_t = Dhall.Core.normalize t + let nf_t' = Dhall.Core.normalize t' + Left (TypeError ctx e (InvalidOptionalElement nf_t x nf_t')) ) + return (App Optional t) +type_with _ OptionalFold = do + return + (Pi "a" (Const Type) + (Pi "_" (App Optional "a") + (Pi "optional" (Const Type) + (Pi "just" (Pi "_" "a" "optional") + (Pi "nothing" "optional" "optional") ) ) ) ) +type_with ctx e@(Record kts ) = do + let process (k, t) = do + s <- fmap Dhall.Core.normalize (type_with ctx t) + case s of + Const Type -> return () + _ -> Left (TypeError ctx e (InvalidFieldType k t)) + mapM_ process (Data.Map.toList kts) + return (Const Type) +type_with ctx e@(RecordLit kvs ) = do + let process (k, v) = do + t <- type_with ctx v + s <- fmap Dhall.Core.normalize (type_with ctx t) + case s of + Const Type -> return () + _ -> Left (TypeError ctx e (InvalidField k v)) + return (k, t) + kts <- mapM process (Data.Map.toAscList kvs) + return (Record (Data.Map.fromAscList kts)) +type_with ctx e@(Union kts ) = do + let process (k, t) = do + s <- fmap Dhall.Core.normalize (type_with ctx t) + case s of + Const Type -> return () + _ -> Left (TypeError ctx e (InvalidAlternativeType k t)) + mapM_ process (Data.Map.toList kts) + return (Const Type) +type_with ctx e@(UnionLit k v kts) = do + case Data.Map.lookup k kts of + Just _ -> Left (TypeError ctx e (DuplicateAlternative k)) + Nothing -> return () + t <- type_with ctx v + let union = Union (Data.Map.insert k t kts) + _ <- type_with ctx union + return union +type_with ctx e@(Combine kvsX kvsY) = do + tKvsX <- fmap Dhall.Core.normalize (type_with ctx kvsX) + ktsX <- case tKvsX of + Record kts -> return kts + _ -> Left (TypeError ctx e (MustCombineARecord kvsX tKvsX)) + + tKvsY <- fmap Dhall.Core.normalize (type_with ctx kvsY) + ktsY <- case tKvsY of + Record kts -> return kts + _ -> Left (TypeError ctx e (MustCombineARecord kvsY tKvsY)) + + let combineTypes ktsL ktsR = do + let ks = + Data.Set.union (Data.Map.keysSet ktsL) (Data.Map.keysSet ktsR) + kts <- forM (toList ks) (\k -> do + case (Data.Map.lookup k ktsL, Data.Map.lookup k ktsR) of + (Just (Record ktsL'), Just (Record ktsR')) -> do + t <- combineTypes ktsL' ktsR' + return (k, t) + (Nothing, Just t) -> do + return (k, t) + (Just t, Nothing) -> do + return (k, t) + _ -> do + Left (TypeError ctx e (FieldCollision k)) ) + return (Record (Data.Map.fromList kts)) + + combineTypes ktsX ktsY +type_with ctx e@(Merge kvsX kvsY t) = do + tKvsX <- fmap Dhall.Core.normalize (type_with ctx kvsX) + ktsX <- case tKvsX of + Record kts -> return kts + _ -> Left (TypeError ctx e (MustMergeARecord kvsX tKvsX)) + let ksX = Data.Map.keysSet ktsX + + tKvsY <- fmap Dhall.Core.normalize (type_with ctx kvsY) + ktsY <- case tKvsY of + Union kts -> return kts + _ -> Left (TypeError ctx e (MustMergeUnion kvsY tKvsY)) + let ksY = Data.Map.keysSet ktsY + + let diffX = Data.Set.difference ksX ksY + let diffY = Data.Set.difference ksY ksX + + if Data.Set.null diffX + then return () + else Left (TypeError ctx e (UnusedHandler diffX)) + + let process (kY, tY) = do + case Data.Map.lookup kY ktsX of + Nothing -> Left (TypeError ctx e (MissingHandler diffY)) + Just tX -> + case tX of + Pi _ tY' t' -> do + if prop_equal tY tY' + then return () + else Left (TypeError ctx e (HandlerInputTypeMismatch kY tY tY')) + if prop_equal t t' + then return () + else Left (TypeError ctx e (HandlerOutputTypeMismatch kY t t')) + _ -> Left (TypeError ctx e (HandlerNotAFunction kY tX)) + mapM_ process (Data.Map.toList ktsY) + return t +type_with ctx e@(Field r x ) = do + t <- fmap Dhall.Core.normalize (type_with ctx r) + case t of + Record kts -> + case Data.Map.lookup x kts of + Just t' -> return t' + Nothing -> Left (TypeError ctx e (MissingField x t)) + _ -> Left (TypeError ctx e (NotARecord x r t)) +type_with ctx (Note s e' ) = case type_with ctx e' of + Left (TypeError ctx2 (Note s' e'') m) -> Left (TypeError ctx2 (Note s' e'') m) + Left (TypeError ctx2 e'' m) -> Left (TypeError ctx2 (Note s e'') m) + Right r -> Right r +type_with _ (Embed p ) = do + absurd p +*/ + _ => panic!("Unimplemented typecheck case: {:?}", e), + } +} + +/// `typeOf` is the same as `type_with` with an empty context, meaning that the +/// expression must be closed (i.e. no free variables), otherwise type-checking +/// will fail. +pub fn type_of<'i, S: Clone + ::std::fmt::Debug + 'i>(e: &Expr<'i, S, X>) -> Result, TypeError<'i, S>> { + let ctx = Context::new(); + type_with(&ctx, e) //.map(|e| e.into_owned()) +} + +/// The specific type error +#[derive(Debug)] +pub enum TypeMessage<'i, S> { + UnboundVariable, + InvalidInputType(Expr<'i, S, X>), + InvalidOutputType(Expr<'i, S, X>), + NotAFunction(Expr<'i, S, X>, Expr<'i, S, X>), + TypeMismatch(Expr<'i, S, X>, Expr<'i, S, X>, Expr<'i, S, X>, Expr<'i, S, X>), + AnnotMismatch(Expr<'i, S, X>, Expr<'i, S, X>, Expr<'i, S, X>), + Untyped, + InvalidListElement(isize, Expr<'i, S, X>, Expr<'i, S, X>, Expr<'i, S, X>), + InvalidListType(Expr<'i, S, X>), + InvalidOptionalElement(Expr<'i, S, X>, Expr<'i, S, X>, Expr<'i, S, X>), + InvalidOptionalLiteral(isize), + InvalidOptionalType(Expr<'i, S, X>), + InvalidPredicate(Expr<'i, S, X>, Expr<'i, S, X>), + IfBranchMismatch(Expr<'i, S, X>, Expr<'i, S, X>, Expr<'i, S, X>, Expr<'i, S, X>), + IfBranchMustBeTerm(bool, Expr<'i, S, X>, Expr<'i, S, X>, Expr<'i, S, X>), + InvalidField(String, Expr<'i, S, X>), + InvalidFieldType(String, Expr<'i, S, X>), + InvalidAlternative(String, Expr<'i, S, X>), + InvalidAlternativeType(String, Expr<'i, S, X>), + DuplicateAlternative(String), + MustCombineARecord(Expr<'i, S, X>, Expr<'i, S, X>), + FieldCollision(String), + MustMergeARecord(Expr<'i, S, X>, Expr<'i, S, X>), + MustMergeUnion(Expr<'i, S, X>, Expr<'i, S, X>), + UnusedHandler(HashSet), + MissingHandler(HashSet), + HandlerInputTypeMismatch(String, Expr<'i, S, X>, Expr<'i, S, X>), + HandlerOutputTypeMismatch(String, Expr<'i, S, X>, Expr<'i, S, X>), + HandlerNotAFunction(String, Expr<'i, S, X>), + NotARecord(String, Expr<'i, S, X>, Expr<'i, S, X>), + MissingField(String, Expr<'i, S, X>), + CantAnd(Expr<'i, S, X>, Expr<'i, S, X>), + CantOr(Expr<'i, S, X>, Expr<'i, S, X>), + CantEQ(Expr<'i, S, X>, Expr<'i, S, X>), + CantNE(Expr<'i, S, X>, Expr<'i, S, X>), + CantStringAppend(Expr<'i, S, X>, Expr<'i, S, X>), + CantAdd(Expr<'i, S, X>, Expr<'i, S, X>), + CantMultiply(Expr<'i, S, X>, Expr<'i, S, X>), + NoDependentLet(Expr<'i, S, X>, Expr<'i, S, X>), + NoDependentTypes(Expr<'i, S, X>, Expr<'i, S, X>), +} + +/// A structured type error that includes context +#[derive(Debug)] +pub struct TypeError<'i, S> { + context: Context<'i, Expr<'i, S, X>>, + current: Expr<'i, S, X>, + type_message: TypeMessage<'i, S>, +} + +impl<'i, S: Clone> TypeError<'i, S> { + pub fn new(context: &Context<'i, Expr<'i, S, X>>, + current: &Expr<'i, S, X>, + type_message: TypeMessage<'i, S>) + -> Self { + TypeError { + context: context.clone(), + current: current.clone(), + type_message: type_message, + } + } +} -- cgit v1.2.3