Merge pull request #396 from edwinb/lazy-lazy

Don't commit to a Force too early

libs/prelude/Builtin.idr

@@ -174,3 +174,11 @@ believe_me = prim__believe_me _ _
 export partial
 idris_crash : String -> a
 idris_crash = prim__crash _
+
+public export
+delay : a -> Lazy a
+delay x = Delay x
+
+public export
+force : Lazy a -> a
+force x = Force x

src/Core/Unify.idr

@@ -1281,8 +1281,13 @@ mutual
 
     unifyWithLazyD _ _ mode loc env (NDelayed _ _ tmx) (NDelayed _ _ tmy)
        = unify (lower mode) loc env tmx tmy
-    unifyWithLazyD _ _ mode loc env (NDelayed _ r tmx) tmy
+    unifyWithLazyD _ _ mode loc env x@(NDelayed _ r tmx) tmy
-       = do vs <- unify (lower mode) loc env tmx tmy
+       = if isHoleApp tmy && not (umode mode == InMatch)
+            -- given type delayed, expected unknown, so let's wait and see
+            -- what the expected type turns out to be
+            then postpone True
+                          loc mode "Postponing in lazy" env x tmy
+            else do vs <- unify (lower mode) loc env tmx tmy
                     pure (record { addLazy = AddForce r } vs)
     unifyWithLazyD _ _ mode loc env tmx (NDelayed _ r tmy)
        = do vs <- unify (lower mode) loc env tmx tmy

tests/Main.idr

@@ -98,6 +98,7 @@ idrisTests
        "reg008", "reg009", "reg010", "reg011", "reg012", "reg013", "reg014",
        "reg015", "reg016", "reg017", "reg018", "reg019", "reg020", "reg021",
        "reg022", "reg023", "reg024", "reg025", "reg026", "reg027", "reg028",
+       "reg029",
        -- Totality checking
        "total001", "total002", "total003", "total004", "total005",
        "total006", "total007", "total008",

tests/ideMode/ideMode001/expected

@@ -2,13 +2,13 @@
 000038(:write-string "1/1: Building LocType (LocType.idr)" 1)
 0000ca(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 7 23) (:end 7 24)) ((:name "x") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "a")))))) 1)
 0000d9(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 7 38) (:end 7 40)) ((:name "ys") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "(Main.Vect m a)")))))) 1)
-0000df(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 7 35) (:end 7 37)) ((:name "xs") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "(Main.Vect {k:269} a)")))))) 1)
+0000df(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 7 35) (:end 7 37)) ((:name "xs") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "(Main.Vect {k:277} a)")))))) 1)
-0000d3(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 7 9) (:end 7 10)) ((:name "x") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "?{_:270}_[]")))))) 1)
+0000d3(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 7 9) (:end 7 10)) ((:name "x") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "?{_:278}_[]")))))) 1)
-0000ed(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 7 14) (:end 7 16)) ((:name "xs") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "(Main.Vect ?{k:269}_[] ?{_:270}_[])")))))) 1)
+0000ed(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 7 14) (:end 7 16)) ((:name "xs") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "(Main.Vect ?{k:277}_[] ?{_:278}_[])")))))) 1)
-0000ed(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 7 18) (:end 7 20)) ((:name "ys") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "(Main.Vect ?{_:271}_[] ?{_:270}_[])")))))) 1)
+0000ed(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 7 18) (:end 7 20)) ((:name "ys") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "(Main.Vect ?{_:279}_[] ?{_:278}_[])")))))) 1)
 0000d9(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 6 16) (:end 6 18)) ((:name "ys") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "(Main.Vect m a)")))))) 1)
-0000ed(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 6 11) (:end 6 13)) ((:name "ys") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "(Main.Vect ?{_:260}_[] ?{_:259}_[])")))))) 1)
+0000ed(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 6 11) (:end 6 13)) ((:name "ys") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "(Main.Vect ?{_:268}_[] ?{_:267}_[])")))))) 1)
-0001cb(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 5 1) (:end 5 48)) ((:name "Main.append") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "{0 m : Prelude.Nat} -> {0 a : Type} -> {0 n : Prelude.Nat} -> (({arg:250} : (Main.Vect n[0] a[1])) -> (({arg:251} : (Main.Vect m[3] a[2])) -> (Main.Vect (Prelude.+ Prelude.Nat Prelude.Num implementation at Prelude.idr:761:1--768:1 n[2] m[4]) a[3])))")))))) 1)
+0001cb(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 5 1) (:end 5 48)) ((:name "Main.append") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "{0 m : Prelude.Nat} -> {0 a : Type} -> {0 n : Prelude.Nat} -> (({arg:258} : (Main.Vect n[0] a[1])) -> (({arg:259} : (Main.Vect m[3] a[2])) -> (Main.Vect (Prelude.+ Prelude.Nat Prelude.Num implementation at Prelude.idr:761:1--768:1 n[2] m[4]) a[3])))")))))) 1)
 0000cc(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 5 47) (:end 5 48)) ((:name "a") (:namespace "") (:decor :type) (:implicit :False) (:key "") (:doc-overview "") (:type "Type")))))) 1)
 0000d3(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 5 44) (:end 5 45)) ((:name "m") (:namespace "") (:decor :type) (:implicit :False) (:key "") (:doc-overview "") (:type "Prelude.Nat")))))) 1)
 0000d3(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 5 40) (:end 5 41)) ((:name "n") (:namespace "") (:decor :type) (:implicit :False) (:key "") (:doc-overview "") (:type "Prelude.Nat")))))) 1)

tests/ideMode/ideMode003/expected

@@ -2,13 +2,13 @@
 000038(:write-string "1/1: Building LocType (LocType.idr)" 1)
 0000ca(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 7 23) (:end 7 24)) ((:name "x") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "a")))))) 1)
 0000d9(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 7 38) (:end 7 40)) ((:name "ys") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "(Main.Vect m a)")))))) 1)
-0000df(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 7 35) (:end 7 37)) ((:name "xs") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "(Main.Vect {k:269} a)")))))) 1)
+0000df(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 7 35) (:end 7 37)) ((:name "xs") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "(Main.Vect {k:277} a)")))))) 1)
-0000d3(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 7 9) (:end 7 10)) ((:name "x") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "?{_:270}_[]")))))) 1)
+0000d3(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 7 9) (:end 7 10)) ((:name "x") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "?{_:278}_[]")))))) 1)
-0000ed(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 7 14) (:end 7 16)) ((:name "xs") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "(Main.Vect ?{k:269}_[] ?{_:270}_[])")))))) 1)
+0000ed(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 7 14) (:end 7 16)) ((:name "xs") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "(Main.Vect ?{k:277}_[] ?{_:278}_[])")))))) 1)
-0000ed(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 7 18) (:end 7 20)) ((:name "ys") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "(Main.Vect ?{_:271}_[] ?{_:270}_[])")))))) 1)
+0000ed(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 7 18) (:end 7 20)) ((:name "ys") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "(Main.Vect ?{_:279}_[] ?{_:278}_[])")))))) 1)
 0000d9(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 6 16) (:end 6 18)) ((:name "ys") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "(Main.Vect m a)")))))) 1)
-0000ed(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 6 11) (:end 6 13)) ((:name "ys") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "(Main.Vect ?{_:260}_[] ?{_:259}_[])")))))) 1)
+0000ed(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 6 11) (:end 6 13)) ((:name "ys") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "(Main.Vect ?{_:268}_[] ?{_:267}_[])")))))) 1)
-0001cb(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 5 1) (:end 5 48)) ((:name "Main.append") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "{0 m : Prelude.Nat} -> {0 a : Type} -> {0 n : Prelude.Nat} -> (({arg:250} : (Main.Vect n[0] a[1])) -> (({arg:251} : (Main.Vect m[3] a[2])) -> (Main.Vect (Prelude.+ Prelude.Nat Prelude.Num implementation at Prelude.idr:761:1--768:1 n[2] m[4]) a[3])))")))))) 1)
+0001cb(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 5 1) (:end 5 48)) ((:name "Main.append") (:namespace "") (:decor :bound) (:implicit :False) (:key "") (:doc-overview "") (:type "{0 m : Prelude.Nat} -> {0 a : Type} -> {0 n : Prelude.Nat} -> (({arg:258} : (Main.Vect n[0] a[1])) -> (({arg:259} : (Main.Vect m[3] a[2])) -> (Main.Vect (Prelude.+ Prelude.Nat Prelude.Num implementation at Prelude.idr:761:1--768:1 n[2] m[4]) a[3])))")))))) 1)
 0000cc(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 5 47) (:end 5 48)) ((:name "a") (:namespace "") (:decor :type) (:implicit :False) (:key "") (:doc-overview "") (:type "Type")))))) 1)
 0000d3(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 5 44) (:end 5 45)) ((:name "m") (:namespace "") (:decor :type) (:implicit :False) (:key "") (:doc-overview "") (:type "Prelude.Nat")))))) 1)
 0000d3(:output (:ok (:highlight-source ((((:filename "LocType.idr") (:start 5 40) (:end 5 41)) ((:name "n") (:namespace "") (:decor :type) (:implicit :False) (:key "") (:doc-overview "") (:type "Prelude.Nat")))))) 1)

tests/idris2/coverage008/expected

@@ -1,6 +1,6 @@
 1/1: Building wcov (wcov.idr)
 Main> Main.tfoo is total
 Main> Main.wfoo is total
-Main> Main.wbar is not covering due to call to function Main.with block in 1393
+Main> Main.wbar is not covering due to call to function Main.with block in 1395
 Main> Main.wbar1 is total
 Main> Bye for now!

tests/idris2/coverage010/expected

@@ -3,4 +3,4 @@ casetot.idr:12:1--13:1:main is not covering at:
 12	main : IO ()
 13	main = do
 
-	Calls non covering function Main.case block in 2146(622)
+	Calls non covering function Main.case block in 2148(630)

tests/idris2/reflection003/expected

@@ -1,6 +1,6 @@
 1/1: Building refprims (refprims.idr)
 LOG 0: Name: Prelude.List.++
-LOG 0: Type: (%pi Rig0 Implicit (Just a) %type (%pi Rig1 Explicit (Just xs) (Prelude.List a) (%pi RigW Explicit (Just {arg:6310}) (Prelude.List a) (Prelude.List a))))
+LOG 0: Type: (%pi Rig0 Implicit (Just a) %type (%pi Rig1 Explicit (Just xs) (Prelude.List a) (%pi RigW Explicit (Just {arg:6318}) (Prelude.List a) (Prelude.List a))))
 LOG 0: Name: Prelude.Strings.++
 LOG 0: Type: (%pi Rig1 Explicit (Just x) String (%pi Rig1 Explicit (Just y) String String))
 LOG 0: Resolved name: Prelude.Nat

tests/idris2/reg029/expected

@@ -0,0 +1 @@
+1/1: Building lqueue (lqueue.idr)

tests/idris2/reg029/lqueue.idr

@@ -0,0 +1,14 @@
+interface Queue (q: Type -> Type) where   
+  empty : q a 
+  isEmpty : q a -> Bool
+  snoc : q a -> a -> q a 
+  head : q a -> a
+  tail : q a -> q a
+
+data CatList : (Type -> Type) -> Type -> Type where
+  E : CatList q a 
+  C : {0 q : Type -> Type} -> a -> q (Lazy (CatList q a)) -> CatList q a
+  
+link : (Queue q) => CatList q a -> Lazy (CatList q a) -> CatList q a 
+link E s = s -- Just to satisfy totality for now.
+link (C x xs) s = C x (snoc xs s)

tests/idris2/reg029/run

@@ -0,0 +1,3 @@
+$1 --check lqueue.idr
+
+rm -rf build