Merge main to release/dev17.7

src/Compiler/Checking/CheckExpressions.fs

@@ -8445,7 +8445,19 @@ and TcUnionCaseOrExnCaseOrActivePatternResultItemThen (cenv: cenv) overallTy env
                 // This is where the constructor expects arguments but is not applied to arguments, hence build a lambda
                 numArgTys,
                 (fun () ->
-                    let vs, args = argTys |> List.mapi (fun i ty -> mkCompGenLocal mItem ("arg" + string i) ty) |> List.unzip
+                    let argNamesIfFeatureEnabled =
+                        if g.langVersion.SupportsFeature LanguageFeature.ImprovedImpliedArgumentNames then
+                            argNames
+                        else
+                            []
+
+                    let vs, args =
+                        argTys
+                        |> List.mapi (fun i ty ->
+                            let argName = argNamesIfFeatureEnabled |> List.tryItem i |> Option.map (fun x -> x.idText) |> Option.defaultWith (fun () -> "arg" + string i)
+                            mkCompGenLocal mItem argName ty)
+                        |> List.unzip
+
                     let constrApp = mkConstrApp mItem args
                     let lam = mkMultiLambda mItem vs (constrApp, tyOfExpr g constrApp)
                     lam)
@@ -9535,7 +9547,13 @@ and TcMethodApplication_CheckArguments
     let denv = env.DisplayEnv
     match curriedCallerArgsOpt with
     | None ->
-        let curriedArgTys, returnTy =
+        let curriedArgTys, curriedArgNamesIfFeatureEnabled, returnTy =
+            let paramNamesIfFeatureEnabled (g: TcGlobals) (meth: MethInfo) =
+                if g.langVersion.SupportsFeature LanguageFeature.ImprovedImpliedArgumentNames then
+                    meth.GetParamNames()
+                else
+                    []
+
             match candidates with
             // "single named item" rule. This is where we have a single accessible method
             //      member x.M(arg1, ..., argN)
@@ -9547,19 +9565,23 @@ and TcMethodApplication_CheckArguments
             // to their default values (for optionals) and be part of the return tuple (for out args).
             | [calledMeth] ->
                 let curriedArgTys, returnTy = UnifyMatchingSimpleArgumentTypes cenv env exprTy.Commit calledMeth mMethExpr mItem
-                curriedArgTys, MustEqual returnTy
+                curriedArgTys, paramNamesIfFeatureEnabled g calledMeth, MustEqual returnTy
             | _ ->
                 let domainTy, returnTy = UnifyFunctionType None cenv denv mMethExpr exprTy.Commit
                 let argTys = if isUnitTy g domainTy then [] else tryDestRefTupleTy g domainTy
                 // Only apply this rule if a candidate method exists with this number of arguments
-                let argTys =
-                    if candidates |> List.exists (CalledMethHasSingleArgumentGroupOfThisLength argTys.Length) then
-                        argTys
-                    else
-                        [domainTy]
-                [argTys], MustEqual returnTy
-
-        let lambdaVarsAndExprs = curriedArgTys |> List.mapiSquared (fun i j ty -> mkCompGenLocal mMethExpr ("arg"+string i+string j) ty)
+                let argTys, argNames =
+                    match candidates |> List.tryFind (CalledMethHasSingleArgumentGroupOfThisLength argTys.Length) with
+                    | Some meth -> argTys, paramNamesIfFeatureEnabled g meth
+                    | None -> [domainTy], [[None]]
+                [argTys], argNames, MustEqual returnTy
+
+        let lambdaVarsAndExprs =
+            curriedArgTys
+            |> List.mapiSquared (fun i j ty ->
+                let argName = curriedArgNamesIfFeatureEnabled |> List.tryItem i |> Option.bind (List.tryItem j) |> Option.flatten |> Option.defaultWith (fun () -> "arg" + string i + string j)
+                mkCompGenLocal mMethExpr argName ty)
+
         let unnamedCurriedCallerArgs = lambdaVarsAndExprs |> List.mapSquared (fun (_, e) -> CallerArg(tyOfExpr g e, e.Range, false, e))
         let namedCurriedCallerArgs = lambdaVarsAndExprs |> List.map (fun _ -> [])
         let lambdaVars = List.mapSquared fst lambdaVarsAndExprs

src/Compiler/Checking/MethodCalls.fs

@@ -1266,8 +1266,23 @@ let BuildNewDelegateExpr (eventInfoOpt: EventInfo option, g, amap, delegateTy, d
             if List.exists (isByrefTy g) delArgTys then
                     error(Error(FSComp.SR.tcFunctionRequiresExplicitLambda(delArgTys.Length), m)) 
 
+            let delFuncArgNamesIfFeatureEnabled =
+                match delFuncExpr with
+                | Expr.Val (valRef = vref) when g.langVersion.SupportsFeature LanguageFeature.ImprovedImpliedArgumentNames ->
+                    match vref.ValReprInfo with
+                    | Some repr when repr.ArgNames.Length = delArgTys.Length -> Some repr.ArgNames
+                    | _ -> None
+                | _ -> None
+
             let delArgVals =
-                delArgTys |> List.mapi (fun i argTy -> fst (mkCompGenLocal m ("delegateArg" + string i) argTy)) 
+                delArgTys
+                |> List.mapi (fun i argTy ->
+                    let argName =
+                        match delFuncArgNamesIfFeatureEnabled with
+                        | Some argNames -> argNames[i]
+                        | None -> "delegateArg" + string i
+
+                    fst (mkCompGenLocal m argName argTy)) 
 
             let expr = 
                 let args = 

src/Compiler/Checking/NicePrint.fs

@@ -168,7 +168,19 @@ module internal PrintUtilities =
         | GenericParameterStyle.Prefix -> true
         | GenericParameterStyle.Suffix -> false
 
-    let layoutTyconRefImpl isAttribute (denv: DisplayEnv) (tcref: TyconRef) =
+    /// <summary>
+    /// Creates a layout for TyconRef.
+    /// </summary>
+    /// <param name="isAttribute"></param>
+    /// <param name="denv"></param>
+    /// <param name="tcref"></param>
+    /// <param name="demangledPath">
+    /// Used in the case the TyconRef is a nested type from another assembly which has generic type parameters in the path.
+    /// For example: System.Collections.Immutable.ImmutableArray&gt;'T&lt;.Builder
+    /// Lead to access path: System.Collections.Immutable.ImmutableArray`1
+    /// ImmutableArray`1 will be transformed to ImmutableArray&gt;'t&lt; 
+    /// </param>
+    let layoutTyconRefImpl isAttribute (denv: DisplayEnv) (tcref: TyconRef) (demangledPath: string list option) =
 
         let prefix = usePrefix denv tcref
         let isArray = not prefix && isArrayTyconRef denv.g tcref
@@ -201,21 +213,22 @@ module internal PrintUtilities =
         if denv.shortTypeNames then 
             tyconTextL
         else
-            let path = tcref.CompilationPath.DemangledPath
             let path =
                 if denv.includeStaticParametersInTypeNames then
-                    path
+                    Option.defaultValue tcref.CompilationPath.DemangledPath demangledPath
                 else
-                    path |> List.map (fun s -> 
+                    tcref.CompilationPath.DemangledPath
+                    |> List.map (fun s -> 
                         let i = s.IndexOf(',')
                         if i <> -1 then s.Substring(0, i)+"<...>" // apparently has static params, shorten
                         else s)
+
             let pathText = trimPathByDisplayEnv denv path
             if pathText = "" then tyconTextL else leftL (tagUnknownEntity pathText) ^^ tyconTextL
 
     let layoutBuiltinAttribute (denv: DisplayEnv) (attrib: BuiltinAttribInfo) =
         let tcref = attrib.TyconRef
-        squareAngleL (layoutTyconRefImpl true denv tcref)
+        squareAngleL (layoutTyconRefImpl true denv tcref None)
 
     /// layout the xml docs immediately before another block
     let layoutXmlDoc (denv: DisplayEnv) alwaysAddEmptyLine (xml: XmlDoc) restL =
@@ -499,7 +512,7 @@ module PrintTypes =
         layoutAccessibilityCore denv accessibility ++ itemL
 
     /// Layout a reference to a type 
-    let layoutTyconRef denv tcref = layoutTyconRefImpl false denv tcref
+    let layoutTyconRef denv tcref = layoutTyconRefImpl false denv tcref None
 
     /// Layout the flags of a member 
     let layoutMemberFlags (memFlags: SynMemberFlags) = 
@@ -571,7 +584,7 @@ module PrintTypes =
 
     /// Layout an attribute 'Type(arg1, ..., argN)' 
     and layoutAttrib denv (Attrib(tcref, _, args, props, _, _, _)) = 
-        let tcrefL = layoutTyconRefImpl true denv tcref
+        let tcrefL = layoutTyconRefImpl true denv tcref None
         let argsL = bracketL (layoutAttribArgs denv args props)
         if List.isEmpty args && List.isEmpty props then
             tcrefL
@@ -900,7 +913,39 @@ module PrintTypes =
         | TType_ucase (UnionCaseRef(tc, _), args)
         | TType_app (tc, args, _) ->
           let prefix = usePrefix denv tc
-          layoutTypeAppWithInfoAndPrec denv env (layoutTyconRef denv tc) prec prefix args
+          let demangledCompilationPathOpt, args =
+              if not denv.includeStaticParametersInTypeNames then
+                  None, args
+              else
+                  let regex = System.Text.RegularExpressions.Regex(@"\`\d+")
+                  let path, skip =
+                      (0, tc.CompilationPath.DemangledPath)
+                      ||> List.mapFold (fun skip path ->
+                          // Verify the path does not contain a generic parameter count.
+                          // For example Foo`3 indicates that there are three parameters in args that belong to this path.
+                          let m = regex.Match(path)
+                          if not m.Success then
+                              path, skip
+                          else
+                              let take = m.Value.Replace("`", "") |> int
+                              let genericArgs =
+                                  List.skip skip args
+                                  |> List.take take
+                                  |> List.map (layoutTypeWithInfoAndPrec denv env prec >> showL)
+                                  |> String.concat ","
+                                  |> sprintf "<%s>"
+                              String.Concat(path.Substring(0, m.Index), genericArgs), (skip + take)
+                      )
+
+                  Some path, List.skip skip args
+
+          layoutTypeAppWithInfoAndPrec
+              denv
+              env
+              (layoutTyconRefImpl false denv tc demangledCompilationPathOpt)
+              prec
+              prefix
+              args
 
         // Layout a tuple type 
         | TType_anon (anonInfo, tys) ->
@@ -1621,7 +1666,7 @@ module TastDefinitionPrinting =
     let layoutExtensionMember denv infoReader (vref: ValRef) =
         let (@@*) = if denv.printVerboseSignatures then (@@----) else (@@--)
         let tycon = vref.MemberApparentEntity.Deref
-        let nameL = layoutTyconRefImpl false denv vref.MemberApparentEntity
+        let nameL = layoutTyconRefImpl false denv vref.MemberApparentEntity None
         let nameL = layoutAccessibility denv tycon.Accessibility nameL // "type-accessibility"
         let tps =
             match PartitionValTyparsForApparentEnclosingType denv.g vref.Deref with
@@ -2615,7 +2660,7 @@ let stringOfFSAttrib denv x = x |> PrintTypes.layoutAttrib denv |> squareAngleL
 
 let stringOfILAttrib denv x = x |> PrintTypes.layoutILAttrib denv |> squareAngleL |> showL
 
-let fqnOfEntityRef g x = x |> layoutTyconRefImpl false (DisplayEnv.Empty g) |> showL
+let fqnOfEntityRef g x = layoutTyconRefImpl false (DisplayEnv.Empty g) x None |> showL
 
 let layoutImpliedSignatureOfModuleOrNamespace showHeader denv infoReader ad m contents =
     InferredSigPrinting.layoutImpliedSignatureOfModuleOrNamespace showHeader denv infoReader ad m contents 

src/Compiler/Checking/infos.fs

@@ -1100,6 +1100,21 @@ type MethInfo =
     member x.GetFSharpReturnType(amap, m, minst) =
         x.GetCompiledReturnType(amap, m, minst) |> GetFSharpViewOfReturnType amap.g
 
+    member x.GetParamNames() =
+        match x with
+        | FSMeth (g, _, vref, _) ->
+            ParamNameAndType.FromMember x.IsCSharpStyleExtensionMember g vref |> List.mapSquared (fun (ParamNameAndType (name, _)) -> name |> Option.map (fun x -> x.idText))
+        | ILMeth (ilMethInfo = ilminfo) ->
+            // A single group of tupled arguments
+            [ ilminfo.ParamMetadata |> List.map (fun x -> x.Name) ]
+#if !NO_TYPEPROVIDERS
+        | ProvidedMeth (_, mi, _, m) ->
+            // A single group of tupled arguments
+            [ [ for p in mi.PApplyArray((fun mi -> mi.GetParameters()), "GetParameters", m) do
+                yield p.PUntaint((fun p -> Some p.Name), m) ] ]
+#endif
+        | _ -> []
+
     /// Get the parameter types of a method info
     member x.GetParamTypes(amap, m, minst) =
         match x with

src/Compiler/Checking/infos.fsi

@@ -517,6 +517,9 @@ type MethInfo =
     /// Get the ParamData objects for the parameters of a MethInfo
     member GetParamDatas: amap: ImportMap * m: range * minst: TType list -> ParamData list list
 
+    /// Get the parameter names of a MethInfo
+    member GetParamNames: unit -> string option list list
+
     /// Get the parameter types of a method info
     member GetParamTypes: amap: ImportMap * m: range * minst: TType list -> TType list list
 

src/Compiler/FSComp.txt

@@ -1573,6 +1573,7 @@ featureNonInlineLiteralsAsPrintfFormat,"String values marked as literals and IL
 featureNestedCopyAndUpdate,"Nested record field copy-and-update"
 featureExtendedStringInterpolation,"Extended string interpolation similar to C# raw string literals."
 featureWarningWhenMultipleRecdTypeChoice,"Raises warnings when multiple record type matches were found during name resolution because of overlapping field names."
+featureImprovedImpliedArgumentNames,"Improved implied argument names"
 3353,fsiInvalidDirective,"Invalid directive '#%s %s'"
 3354,tcNotAFunctionButIndexerNamedIndexingNotYetEnabled,"This value supports indexing, e.g. '%s.[index]'. The syntax '%s[index]' requires /langversion:preview. See https://aka.ms/fsharp-index-notation."
 3354,tcNotAFunctionButIndexerIndexingNotYetEnabled,"This expression supports indexing, e.g. 'expr.[index]'. The syntax 'expr[index]' requires /langversion:preview. See https://aka.ms/fsharp-index-notation."

src/Compiler/Facilities/LanguageFeatures.fs

@@ -68,6 +68,7 @@ type LanguageFeature =
     | NestedCopyAndUpdate
     | ExtendedStringInterpolation
     | WarningWhenMultipleRecdTypeChoice
+    | ImprovedImpliedArgumentNames
 
 /// LanguageVersion management
 type LanguageVersion(versionText) =
@@ -159,6 +160,7 @@ type LanguageVersion(versionText) =
                 LanguageFeature.NestedCopyAndUpdate, previewVersion
                 LanguageFeature.ExtendedStringInterpolation, previewVersion
                 LanguageFeature.WarningWhenMultipleRecdTypeChoice, previewVersion
+                LanguageFeature.ImprovedImpliedArgumentNames, previewVersion
 
             ]
 
@@ -282,6 +284,7 @@ type LanguageVersion(versionText) =
         | LanguageFeature.NestedCopyAndUpdate -> FSComp.SR.featureNestedCopyAndUpdate ()
         | LanguageFeature.ExtendedStringInterpolation -> FSComp.SR.featureExtendedStringInterpolation ()
         | LanguageFeature.WarningWhenMultipleRecdTypeChoice -> FSComp.SR.featureWarningWhenMultipleRecdTypeChoice ()
+        | LanguageFeature.ImprovedImpliedArgumentNames -> FSComp.SR.featureImprovedImpliedArgumentNames ()
 
     /// Get a version string associated with the given feature.
     static member GetFeatureVersionString feature =

src/Compiler/Facilities/LanguageFeatures.fsi

@@ -58,6 +58,7 @@ type LanguageFeature =
     | NestedCopyAndUpdate
     | ExtendedStringInterpolation
     | WarningWhenMultipleRecdTypeChoice
+    | ImprovedImpliedArgumentNames
 
 /// LanguageVersion management
 type LanguageVersion =

src/Compiler/TypedTree/TypedTreeOps.fs

@@ -3117,7 +3117,8 @@ type DisplayEnv =
                suppressInlineKeyword = false
                showDocumentation = true
                shrinkOverloads = false
-               escapeKeywordNames = true }
+               escapeKeywordNames = true
+               includeStaticParametersInTypeNames = true }
         denv.SetOpenPaths
             [ FSharpLib.RootPath
               FSharpLib.CorePath

src/Compiler/xlf/FSComp.txt.cs.xlf

@@ -272,6 +272,11 @@
         <target state="translated">implicitní yield</target>
         <note />
       </trans-unit>
+      <trans-unit id="featureImprovedImpliedArgumentNames">
+        <source>Improved implied argument names</source>
+        <target state="new">Improved implied argument names</target>
+        <note />
+      </trans-unit>
       <trans-unit id="featureIndexerNotationWithoutDot">
         <source>expr[idx] notation for indexing and slicing</source>
         <target state="translated">Notace expr[idx] pro indexování a vytváření řezů</target>

src/Compiler/xlf/FSComp.txt.de.xlf

@@ -272,6 +272,11 @@
         <target state="translated">implizite yield-Anweisung</target>
         <note />
       </trans-unit>
+      <trans-unit id="featureImprovedImpliedArgumentNames">
+        <source>Improved implied argument names</source>
+        <target state="new">Improved implied argument names</target>
+        <note />
+      </trans-unit>
       <trans-unit id="featureIndexerNotationWithoutDot">
         <source>expr[idx] notation for indexing and slicing</source>
         <target state="translated">expr[idx]-Notation zum Indizieren und Aufteilen</target>

src/Compiler/xlf/FSComp.txt.es.xlf

@@ -272,6 +272,11 @@
         <target state="translated">elemento yield implícito</target>
         <note />
       </trans-unit>
+      <trans-unit id="featureImprovedImpliedArgumentNames">
+        <source>Improved implied argument names</source>
+        <target state="new">Improved implied argument names</target>
+        <note />
+      </trans-unit>
       <trans-unit id="featureIndexerNotationWithoutDot">
         <source>expr[idx] notation for indexing and slicing</source>
         <target state="translated">Notación para indexación y segmentación expr[idx]</target>

src/Compiler/xlf/FSComp.txt.fr.xlf

@@ -272,6 +272,11 @@
         <target state="translated">yield implicite</target>
         <note />
       </trans-unit>
+      <trans-unit id="featureImprovedImpliedArgumentNames">
+        <source>Improved implied argument names</source>
+        <target state="new">Improved implied argument names</target>
+        <note />
+      </trans-unit>
       <trans-unit id="featureIndexerNotationWithoutDot">
         <source>expr[idx] notation for indexing and slicing</source>
         <target state="translated">Notation expr[idx] pour l’indexation et le découpage</target>

src/Compiler/xlf/FSComp.txt.it.xlf

@@ -272,6 +272,11 @@
         <target state="translated">istruzione yield implicita</target>
         <note />
       </trans-unit>
+      <trans-unit id="featureImprovedImpliedArgumentNames">
+        <source>Improved implied argument names</source>
+        <target state="new">Improved implied argument names</target>
+        <note />
+      </trans-unit>
       <trans-unit id="featureIndexerNotationWithoutDot">
         <source>expr[idx] notation for indexing and slicing</source>
         <target state="translated">Notazione expr[idx] per l'indicizzazione e il sezionamento</target>

src/Compiler/xlf/FSComp.txt.ja.xlf

@@ -272,6 +272,11 @@
         <target state="translated">暗黙的な yield</target>
         <note />
       </trans-unit>
+      <trans-unit id="featureImprovedImpliedArgumentNames">
+        <source>Improved implied argument names</source>
+        <target state="new">Improved implied argument names</target>
+        <note />
+      </trans-unit>
       <trans-unit id="featureIndexerNotationWithoutDot">
         <source>expr[idx] notation for indexing and slicing</source>
         <target state="translated">インデックス作成とスライス用の expr[idx] 表記</target>

src/Compiler/xlf/FSComp.txt.ko.xlf

@@ -272,6 +272,11 @@
         <target state="translated">암시적 yield</target>
         <note />
       </trans-unit>
+      <trans-unit id="featureImprovedImpliedArgumentNames">
+        <source>Improved implied argument names</source>
+        <target state="new">Improved implied argument names</target>
+        <note />
+      </trans-unit>
       <trans-unit id="featureIndexerNotationWithoutDot">
         <source>expr[idx] notation for indexing and slicing</source>
         <target state="translated">인덱싱 및 슬라이싱을 위한 expr[idx] 표기법</target>