Add Eq instances for AnyTemplate, AnyChoice and AnyContractKey (digit…

…al-asset#3816) * Add Eq instances for AnyTemplate, AnyChoice and AnyContractKey CHANGELOG_BEGIN - [DAML Standard Library] Add ``Eq`` instances for ``AnyTemplate``, ``AnyChoice`` and ``AnyContractKey``. CHANGELOG_END * Add DAML_ANY_TYPE to the CPP guard
iggy-da · Dec 11, 2019 · 013d668 · 013d668
1 parent ac47a84
commit 013d668
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diff --git a/compiler/damlc/daml-stdlib-src/DA/Internal/LF.daml b/compiler/damlc/daml-stdlib-src/DA/Internal/LF.daml
@@ -243,6 +243,28 @@ data AnyContractKey = AnyContractKey
   , getanyContractKeyTemplateRep : TemplateTypeRep
   }
 
+#ifdef DAML_GENMAP && DAML_ANY_TYPE
+-- We do not separate generic equality from generic maps so this guards on DAML_GENMAP.
+
+-- We do not have a general Eq instance for Any since Any is not exposed
+-- to users directly and that instance will crash on some values but
+-- we can have total Eq instances for AnyTemplate, AnyChoice and AnyContractKey
+-- since those are guaranteed to be serializable.
+eqAny : Any -> Any -> Bool
+eqAny = primitive @"BEEqual"
+
+instance Eq AnyTemplate where
+  AnyTemplate a == AnyTemplate b = eqAny a b
+
+instance Eq AnyChoice where
+  AnyChoice aAny aRep == AnyChoice bAny bRep =
+    eqAny aAny bAny && aRep == bRep
+
+instance Eq AnyContractKey where
+  AnyContractKey aAny aRep == AnyContractKey bAny bRep =
+    eqAny aAny bAny && aRep == bRep
+#endif
+
 -- | Value-level representation of a type.
 -- We do not expose this directly and instead only expose TemplateTypeRep.
 data TypeRep = TypeRep Opaque

diff --git a/compiler/damlc/tests/daml-test-files/AnyEq.daml b/compiler/damlc/tests/daml-test-files/AnyEq.daml
@@ -0,0 +1,58 @@
+-- Copyright (c) 2019, Digital Asset (Switzerland) GmbH and/or its affiliates.
+-- All rights reserved.
+
+-- @SINCE-LF 1.8
+daml 1.2
+module AnyEq where
+
+import DA.Action
+
+template T1
+  with
+    x : Int
+    p : Party
+  where
+    signatory p
+    key p : Party
+    maintainer key
+    choice C : ()
+      controller p
+      do pure ()
+
+template T1'
+  with
+    x : Int
+    p : Party
+  where
+    signatory p
+    key p : Party
+    maintainer key
+
+template T2
+  with
+    y : Text
+    p : Party
+  where
+    signatory p
+    key (p, y) : (Party, Text)
+    maintainer key._1
+
+-- We don’t have a Show instance for AnyTemplate so we cannot use ===
+
+assertBool : CanAbort m => Text -> Bool -> m ()
+assertBool err success = unless success $ abort ("Failure: " <> show err)
+
+main = scenario do
+  p <- getParty "alice"
+  let t1A = T1 0 p
+  let t1B = T1 1 p
+  let t1'A = T1' 0 p
+  assertBool (show (t1A, t1A)) (toAnyTemplate t1A == toAnyTemplate t1A)
+  assertBool (show (t1A, t1B)) (toAnyTemplate t1A /= toAnyTemplate t1B)
+  assertBool (show (t1'A, t1'A)) (toAnyTemplate t1'A == toAnyTemplate t1'A)
+  assertBool (show (t1A, t1'A)) (toAnyTemplate t1A /= toAnyTemplate t1'A)
+  assertBool (show (C, C)) (toAnyChoice @T1 C == toAnyChoice @T1 C)
+  assertBool (show (C, Archive)) (toAnyChoice @T1 C /= toAnyChoice @T1 Archive)
+  assertBool ("T1, T2" <> show (Archive, Archive)) (toAnyChoice @T1 C /= toAnyChoice @T2 Archive)
+  assertBool ("T1, T1'" <> show (p, p)) (toAnyContractKey @T1 p /= toAnyContractKey @T1' p)
+  assertBool ("T1, T1" <> show (p, p)) (toAnyContractKey @T1 p == toAnyContractKey @T1 p)