Suggest a function to implement

Author: forki

src/fsharp/FSComp.txt

@@ -588,7 +588,7 @@ tcExpressionWithIfRequiresParenthesis,"This list or array expression includes an
 764,tcFieldRequiresAssignment,"No assignment given for field '%s' of type '%s'"
 765,tcExtraneousFieldsGivenValues,"Extraneous fields have been given values"
 766,tcObjectExpressionsCanOnlyOverrideAbstractOrVirtual,"Only overrides of abstract and virtual members may be specified in object expressions"
-767,tcNoAbstractOrVirtualMemberFound,"The member '%s' does not correspond to any abstract or virtual method available to override or implement"
+767,tcNoAbstractOrVirtualMemberFound,"The member '%s' does not correspond to any abstract or virtual method available to override or implement.%s"
 768,tcArgumentArityMismatch,"The member '%s' does not accept the correct number of arguments, %d arguments are expected"
 769,tcArgumentArityMismatchOneOverload,"The member '%s' does not accept the correct number of arguments. One overload accepts %d arguments."
 770,tcSimpleMethodNameRequired,"A simple method name is required here"

src/fsharp/TypeChecker.fs

@@ -6209,7 +6209,13 @@ and FreshenObjExprAbstractSlot cenv (_env: TcEnv) implty virtNameAndArityPairs (
         let absSlotsByName = List.filter (fst >> fst >> (=) bindName) virtNameAndArityPairs
 
         match absSlotsByName with 
-        | []              -> errorR(Error(FSComp.SR.tcNoAbstractOrVirtualMemberFound(bindName),mBinding))
+        | []              ->
+            let predictions =
+                virtNameAndArityPairs
+                |> List.map (fst >> fst)
+                |> ErrorResolutionHints.FilterPredictions bindName
+
+            errorR(Error(FSComp.SR.tcNoAbstractOrVirtualMemberFound(bindName, ErrorResolutionHints.FormatPredictions predictions),mBinding))
         | [(_,absSlot:MethInfo)]     -> errorR(Error(FSComp.SR.tcArgumentArityMismatch(bindName, (List.sum absSlot.NumArgs)),mBinding))
         | (_,absSlot:MethInfo) :: _  -> errorR(Error(FSComp.SR.tcArgumentArityMismatchOneOverload(bindName, (List.sum absSlot.NumArgs)),mBinding))
 

tests/fsharpqa/Source/Warnings/NoMatchingAbstractMethodWithSameName.fs

@@ -0,0 +1,14 @@
+// #Warnings
+//<Expects status="Error" span="(11,14)" id="FS0767">The member 'Function' does not correspond to any abstract or virtual method available to override or implement.</Expects>
+//<Expects>MyFunction</Expects>
+
+type IInterface =
+    abstract MyFunction : int32 * int32 -> unit
+    abstract SomeOtherFunction : int32 * int32 -> unit
+
+let x = 
+  { new IInterface with
+      member this.Function (i, j) = ()
+  }
+
+exit 0

tests/fsharpqa/Source/Warnings/env.lst

@@ -5,6 +5,7 @@
 	SOURCE=CommaInRecCtor.fs # CommaInRecCtor.fs
 	SOURCE=ValidCommaInRecCtor.fs # ValidCommaInRecCtor.fs
 	SOURCE=ElseBranchHasWrongType.fs # ElseBranchHasWrongType.fs
+	SOURCE=NoMatchingAbstractMethodWithSameName.fs # NoMatchingAbstractMethodWithSameName.fs
 	SOURCE=MissingExpressionAfterLet.fs # MissingExpressionAfterLet.fs
 	SOURCE=AssignmentOnImmutable.fs # AssignmentOnImmutable.fs
 	SOURCE=UpcastInsteadOfDowncast.fs # UpcastInsteadOfDowncast.fs