use the syntax <x : A> in PGF.Expr for typed expressions. This is consistent with the GF language

src/PGF/Expr.hs

@@ -127,28 +127,27 @@ unDouble (ELit (LFlt f)) = Just f
 -----------------------------------------------------
 
 pExpr :: RP.ReadP Expr
-pExpr = pExpr0 >>= optTyped
+pExpr = RP.skipSpaces >> (pAbs RP.<++ pTerm)
   where
-    pExpr0  = RP.skipSpaces >> (pAbs RP.<++ pTerm)
-
     pTerm   =       fmap (foldl1 EApp) (RP.sepBy1 pFactor RP.skipSpaces)
 
     pAbs = do xs <- RP.between (RP.char '\\') (RP.skipSpaces >> RP.string "->") (RP.sepBy1 (RP.skipSpaces >> pCId) (RP.skipSpaces >> RP.char ','))
-              e  <- pExpr0
+              e  <- pExpr
               return (foldr EAbs e xs)
-
-    optTyped e = do RP.skipSpaces
-                    RP.char ':'
-                    RP.skipSpaces
-                    ty <- pType
-                    return (ETyped e ty)
-                 RP.<++
-                 return e 
                  
 pFactor =       fmap EFun  pCId
         RP.<++  fmap ELit  pLit
         RP.<++  fmap EMeta pMeta
         RP.<++  RP.between (RP.char '(') (RP.char ')') pExpr
+        RP.<++  RP.between (RP.char '<') (RP.char '>') pTyped
+
+pTyped = do RP.skipSpaces
+            e <- pExpr
+            RP.skipSpaces
+            RP.char ':'
+            RP.skipSpaces
+            ty <- pType
+            return (ETyped e ty)
 
 pMeta = do RP.char '?'
            return 0
@@ -184,7 +183,7 @@ ppExpr d scope (ELit l)     = ppLit l
 ppExpr d scope (EMeta n)    = ppMeta n
 ppExpr d scope (EFun f)     = ppCId f
 ppExpr d scope (EVar i)     = ppCId (scope !! i)
-ppExpr d scope (ETyped e ty)= ppParens (d > 0) (ppExpr 0 scope e PP.<+> PP.colon PP.<+> ppType 0 scope ty)
+ppExpr d scope (ETyped e ty)= PP.char '<' PP.<> ppExpr 0 scope e PP.<+> PP.colon PP.<+> ppType 0 scope ty PP.<> PP.char '>'
 
 ppPatt :: Int -> [CId] -> Patt -> ([CId],PP.Doc)
 ppPatt d scope (PApp f ps) = let (scope',ds) = mapAccumL (ppPatt 2) scope ps

testsuite/runtime/eval/eval.gfs

@@ -1,28 +1,28 @@
 i -src testsuite/runtime/eval/Test.gf
 
-pt -compute \x -> x 1 : (Int->Int)->Int
+pt -compute <\x -> x 1 : (Int->Int)->Int>
-pt -compute (? : Int -> Int) 1
+pt -compute <? : Int -> Int> 1
-pt -compute (\x -> x 1 : (Int->Int)->Int) ?
+pt -compute <\x -> x 1 : (Int->Int)->Int> ?
 pt -compute f 1 2
-pt -compute \x -> x : Nat -> Nat
+pt -compute <\x -> x : Nat -> Nat>
-pt -compute ? : String
+pt -compute <? : String>
 pt -compute f
-pt -compute (\x -> x 2 : (Int->Int)->Int) (f 1)
+pt -compute <\x -> x 2 : (Int->Int)->Int> (f 1)
 pt -compute g 1
 pt -compute g 0
-pt -compute \x -> g x : Int -> Int
+pt -compute <\x -> g x : Int -> Int>
 pt -compute g ?
-pt -compute (\x -> x 5 : (Int->Int)->Int) (g2 1)
+pt -compute <\x -> x 5 : (Int->Int)->Int> (g2 1)
-pt -compute (\x -> x 3 : (Int->Int)->Int) (\x -> x)
+pt -compute <\x -> x 3 : (Int->Int)->Int> (\x -> x)
 pt -compute g0
-pt -compute (\x -> x 32 : (Int -> Int -> Int) -> Int -> Int) (\x -> f x : Int -> Int -> Int)
+pt -compute <\x -> x 32 : (Int -> Int -> Int) -> Int -> Int> <\x -> f x : Int -> Int -> Int>
 pt -compute g0 23
 pt -compute const 3.14 "pi"
 pt -compute dec (succ (succ zero))
 pt -compute dec (succ ?)
-pt -compute \x -> dec x : Nat -> Nat
+pt -compute <\x -> dec x : Nat -> Nat>
 pt -compute dec ?
-pt -compute (\f -> f 0 : (Int -> Int) -> Int) (g3 ?)
+pt -compute <\f -> f 0 : (Int -> Int) -> Int> (g3 ?)
 pt -compute g (g2 ? 0)
 pt -compute plus (succ zero) (succ zero)
 pt -compute dec2 0 (succ zero)

testsuite/runtime/typecheck/typecheck.gfs

@@ -1,22 +1,22 @@
 i -src testsuite/runtime/typecheck/Test.gf
 
 ai succ "0"
-ai succ : Int 0
+ai <succ : Int 0>
 ai 1 2
-ai (\x -> x 2 : (Int->Int)->Int) 1
+ai <\x -> x 2 : (Int->Int)->Int> 1
 ai unknown_fun
-ai 0 : unknown_cat
+ai <0 : unknown_cat>
 ai \x -> x
-ai \x -> x : Int
+ai <\x -> x : Int>
 ai append (succ (succ zero)) (succ zero) (vector (succ (succ zero))) (vector (succ zero))
-ai \m,n -> vector (plus m n) : (m,n : Nat) -> Vector (plus m n)
+ai <\m,n -> vector (plus m n) : (m,n : Nat) -> Vector (plus m n)>
 ai mkMorph (\x -> succ zero)
 ai idMorph (mkMorph (\x -> x))
 ai idMorph (mkMorph (\x -> succ zero))
-ai append zero (succ zero) : Vector zero -> Vector (succ zero) -> Vector (succ zero)
+ai <append zero (succ zero) : Vector zero -> Vector (succ zero) -> Vector (succ zero)>
-ai \n,v1,n,v2 -> append ? ? v1 v2 : (n : Nat) -> Vector n -> (m : Nat) -> Vector m -> Vector (plus n m)
+ai <\n,v1,n,v2 -> append ? ? v1 v2 : (n : Nat) -> Vector n -> (m : Nat) -> Vector m -> Vector (plus n m)>
-ai \n -> (\v1,v2 -> eqVector n v1 v2 : Vector ? -> Vector ? -> EQ) (vector ?) : (n : Nat) -> Vector n -> EQ
+ai <\n -> <\v1,v2 -> eqVector n v1 v2 : Vector ? -> Vector ? -> EQ> (vector ?) : (n : Nat) -> Vector n -> EQ>
-ai (\v1,v2 -> cmpVector ? v1 v2 : Vector ? -> Vector ? -> Int) (vector ?) 
+ai <\v1,v2 -> cmpVector ? v1 v2 : Vector ? -> Vector ? -> Int> (vector ?) 
 ai f0 ? vector
 ai f1 ? vector
 ai f1 ? (\x -> vector (succ x))

testsuite/runtime/typecheck/typecheck.gfs.gold

@@ -1,16 +1,9 @@
-␍
 Couldn't match expected type Nat␍
        against inferred type String␍
 In the expression: "0"␍
-␍
-␍
 Category Int should have 0 argument(s), but has been given 1␍
 In the type: Int 0␍
-␍
-␍
 A function type is expected for the expression 1 instead of type Int␍
-␍
-␍
 Couldn't match expected type Int -> Int␍
        against inferred type Int␍
 In the expression: 1␍
@@ -20,17 +13,12 @@ Function unknown_fun is not in scope
 ␍
 ␍
 Category unknown_cat is not in scope␍
-␍
-␍
 Cannot infer the type of expression \x -> x␍
-␍
-␍
 A function type is expected for the expression \x -> x instead of type Int␍
-␍
 Expression: append (succ (succ zero)) (succ zero) (vector (succ (succ zero))) (vector (succ zero))␍
 Type:       Vector (plus (succ (succ zero)) (succ zero))␍
 ␍
-Expression: \m, n -> vector (plus m n) : (m : Nat) -> (n : Nat) -> Vector (plus m n)␍
+Expression: <\m, n -> vector (plus m n) : (m : Nat) -> (n : Nat) -> Vector (plus m n)>␍
 Type:       (m : Nat) -> (n : Nat) -> Vector (plus m n)␍
 ␍
 Expression: mkMorph (\x -> succ zero)␍
@@ -39,64 +27,48 @@ Type:       Morph (\x -> succ zero)
 Expression: idMorph (mkMorph (\x -> x))␍
 Type:       Nat␍
 ␍
-␍
 Couldn't match expected type Morph (\x -> x)␍
        against inferred type Morph (\x -> succ zero)␍
 In the expression: mkMorph (\x -> succ zero)␍
-␍
+Expression: <append zero (succ zero) : Vector zero -> Vector (succ zero) -> Vector (succ zero)>␍
-Expression: append zero (succ zero) : Vector zero -> Vector (succ zero) -> Vector (succ zero)␍
 Type:       Vector zero -> Vector (succ zero) -> Vector (succ zero)␍
 ␍
-Expression: \n, v1, n'1, v2 -> append n n'1 v1 v2 : (n : Nat) -> Vector n -> (m : Nat) -> Vector m -> Vector (plus n m)␍
+Expression: <\n, v1, n'1, v2 -> append n n'1 v1 v2 : (n : Nat) -> Vector n -> (m : Nat) -> Vector m -> Vector (plus n m)>␍
 Type:       (n : Nat) -> Vector n -> (m : Nat) -> Vector m -> Vector (plus n m)␍
 ␍
-␍
 Category EQ is not in scope␍
-␍
+Expression: <\v1, v2 -> cmpVector ?7 v1 v2 : Vector ?7 -> Vector ?7 -> Int> (vector ?7)␍
-Expression: (\v1, v2 -> cmpVector ?7 v1 v2 : Vector ?7 -> Vector ?7 -> Int) (vector ?7)␍
 Type:       Vector ?7 -> Int␍
 ␍
-␍
 Couldn't match expected type (m : Nat) -> Vector ?1␍
        against inferred type (n : Nat) -> Vector n␍
 In the expression: vector␍
-␍
 Expression: f1 (\v -> v) vector␍
 Type:       Int␍
 ␍
 Expression: f1 (\v -> succ v) (\x -> vector (succ x))␍
 Type:       Int␍
 ␍
-␍
 Couldn't match expected type Vector x␍
        against inferred type Vector (succ x)␍
 In the expression: vector (succ x)␍
-␍
-␍
 Couldn't match expected type Vector n␍
        against inferred type Vector (succ n)␍
 In the expression: vector (succ n)␍
-␍
 Expression: h ?2 (u0 ?2)␍
 Type:       Int␍
 ␍
-␍
 Couldn't match expected type U ?2 ?2␍
        against inferred type U ?2 (succ ?2)␍
 In the expression: u1 ?2␍
-␍
-␍
 Meta variable(s) ?11 should be resolved␍
 in the expression: cmpVector (succ (succ zero)) (vector (succ (succ zero))) (append ?11 (succ zero) (vector ?11) (vector (succ zero)))␍
-␍
 Expression: diff (succ (succ (succ zero))) (succ (succ zero)) (vector (succ (succ (succ (succ (succ zero)))))) (vector (succ (succ (succ zero))))␍
 Type:       Vector (succ (succ zero))␍
 ␍
 Couldn't match expected type Vector (plus (succ (succ (succ zero))) (succ (succ zero)))␍
        against inferred type Vector (succ (succ (succ (succ zero))))␍
 In the expression: vector (succ (succ (succ (succ zero))))␍
-␍
 Couldn't match expected type Vector ?1␍
        against inferred type Vector zero␍
 In the expression: vector zero␍
-␍