Use logical operator name to check for logical ternary operator (#14495)

Author: rosskuehl

src/Compiler/Checking/CheckExpressions.fs

@@ -1015,15 +1015,16 @@ let MakeMemberDataAndMangledNameForMemberVal(g, tcref, isExtrinsic, attrs, implS
 
     if not isCompGen && IsLogicalInfixOpName id.idText then
         let m = id.idRange
-        let name = ConvertValLogicalNameToDisplayNameCore id.idText
+        let logicalName = id.idText
+        let displayName = ConvertValLogicalNameToDisplayNameCore logicalName
         // Check symbolic members. Expect valSynData implied arity to be [[2]].
         match SynInfo.AritiesOfArgs valSynData with
-        | [] | [0] -> warning(Error(FSComp.SR.memberOperatorDefinitionWithNoArguments name, m))
+        | [] | [0] -> warning(Error(FSComp.SR.memberOperatorDefinitionWithNoArguments displayName, m))
         | n :: otherArgs ->
-            let opTakesThreeArgs = IsLogicalTernaryOperator name
-            if n<>2 && not opTakesThreeArgs then warning(Error(FSComp.SR.memberOperatorDefinitionWithNonPairArgument(name, n), m))
-            if n<>3 && opTakesThreeArgs then warning(Error(FSComp.SR.memberOperatorDefinitionWithNonTripleArgument(name, n), m))
-            if not (isNil otherArgs) then warning(Error(FSComp.SR.memberOperatorDefinitionWithCurriedArguments name, m))
+            let opTakesThreeArgs = IsLogicalTernaryOperator logicalName
+            if n<>2 && not opTakesThreeArgs then warning(Error(FSComp.SR.memberOperatorDefinitionWithNonPairArgument(displayName, n), m))
+            if n<>3 && opTakesThreeArgs then warning(Error(FSComp.SR.memberOperatorDefinitionWithNonTripleArgument(displayName, n), m))
+            if not (isNil otherArgs) then warning(Error(FSComp.SR.memberOperatorDefinitionWithCurriedArguments displayName, m))
 
     if isExtrinsic && IsLogicalOpName id.idText then
         warning(Error(FSComp.SR.tcMemberOperatorDefinitionInExtrinsic(), id.idRange))

tests/FSharp.Compiler.ComponentTests/FSharp.Compiler.ComponentTests.fsproj

@@ -173,6 +173,7 @@
     <Compile Include="Language\CodeQuotationTests.fs" />
     <Compile Include="Language\InterpolatedStringsTests.fs" />
     <Compile Include="Language\ComputationExpressionTests.fs" />
+    <Compile Include="Language\DynamicAssignmentOperatorTests.fs" />
     <Compile Include="Language\CastingTests.fs" />
     <Compile Include="Language\NameofTests.fs" />
     <Compile Include="Language\ExtensionMethodTests.fs" />

tests/FSharp.Compiler.ComponentTests/Language/DynamicAssignmentOperatorTests.fs

@@ -0,0 +1,21 @@
+// Copyright (c) Microsoft Corporation.  All Rights Reserved.  See License.txt in the project root for license information.
+
+namespace FSharp.Compiler.ComponentTests.Language
+
+open System
+open Xunit
+open FSharp.Test.Compiler
+
+module DynamicAssignmentOperatorTests =
+
+    [<Theory>]
+    [<InlineData("6.0")>]
+    [<InlineData("7.0")>]
+    let ``Implementing dynamic assignment operator does not produce a warning`` version = 
+        Fsx """
+        type T = T with
+            static member inline (?<-) (f, x, y) = f x y
+        """
+        |> withLangVersion version
+        |> compile
+        |> shouldSucceed