Intellisense completion for named parameters

closes #220

commit 4c59b117cf64e3b85c885f32b7fe50560b44f028
Author: Vladimir Matveev <vladima@microsoft.com>
Date:   Fri Feb 13 15:42:51 2015 -0800

    do not drop error arguments entirely, but ignore them then validating consistency of positional\named arguments

commit c3a65310c6ac619c233913d1072efc8753f6d4a9
Author: Vladimir Matveev <vladima@microsoft.com>
Date:   Wed Feb 11 11:24:52 2015 -0800

    added unit tests for completion of named arguments\settable properties

commit 27a2b6307cfe55db24e2f3a5a5ae3727d0c9d182
Author: Vladimir Matveev <vladima@microsoft.com>
Date:   Wed Feb 11 11:23:57 2015 -0800

    do not abort overload resolution if parameter list contains errors

commit 2851370637c67afd634d9a05b667b0b4172fc590
Author: Vladimir Matveev <vladima@microsoft.com>
Date:   Sat Feb 7 01:11:09 2015 -0800

    initial version of completion for named parameters

src/fsharp/tc.fs

@@ -3018,11 +3018,16 @@ let GetMethodArgs arg =
         | SynExpr.Const (SynConst.Unit,_) -> []
         | SynExprParen(SynExpr.Tuple (args,_,_),_,_,_) | SynExpr.Tuple (args,_,_) -> args
         | SynExprParen(arg,_,_,_) | arg -> [arg]
-    let unnamedCallerArgs,namedCallerArgs = List.takeUntil IsNamedArg args
+    let unnamedCallerArgs,namedCallerArgs = 
+        args |> List.takeUntil IsNamedArg
     let namedCallerArgs = 
         namedCallerArgs |> List.choose (fun e -> 
-          if not (IsNamedArg e) then 
-              error(Error(FSComp.SR.tcNameArgumentsMustAppearLast(), e.Range)) 
+          if not (IsNamedArg e) then
+              // ignore errors to avoid confusing error messages in cases like foo(a = 1,) 
+              // do not abort overload resolution in case if named arguments are mixed with errors
+              match e with
+              | SynExpr.ArbitraryAfterError _ -> ()
+              | _ -> error(Error(FSComp.SR.tcNameArgumentsMustAppearLast(), e.Range)) 
           TryGetNamedArg e)
     unnamedCallerArgs, namedCallerArgs
 

src/fsharp/vs/ServiceUntypedParse.fs

@@ -70,7 +70,9 @@ type internal CompletionContext =
     // completing records field
     | RecordField of RecordContext
     | RangeOperator
-    | NewObject of pos * HashSet<string>
+    // completing named parameters\setters in parameter list of constructor\method calls
+    // end of name ast node * list of properties\parameters that were already set
+    | ParameterList of pos * HashSet<string>
 
 //----------------------------------------------------------------------------
 // Untyped scope
@@ -772,7 +774,7 @@ module internal UntypedParseInfoImpl =
             | Some m -> m.End
             | None -> id.idRange.End
 
-        let (|NewObject|_|) e =
+        let (|NewObjectOrMethodCall|_|) e =
             match e with
             | (SynExpr.New (_, SynType.LongIdent typeName, arg, _)) -> 
                 // new A()
@@ -808,9 +810,9 @@ module internal UntypedParseInfoImpl =
 
         let (|PartOfParameterList|_|) precedingArgument path =
             match path with
-            | TS.Expr(SynExpr.Paren _)::TS.Expr(NewObject(args))::_ -> 
+            | TS.Expr(SynExpr.Paren _)::TS.Expr(NewObjectOrMethodCall(args))::_ -> 
                 if Option.isSome precedingArgument then None else Some args
-            | TS.Expr(SynExpr.Tuple (elements, commas, _))::TS.Expr(SynExpr.Paren _)::TS.Expr(NewObject(args))::_ -> 
+            | TS.Expr(SynExpr.Tuple (elements, commas, _))::TS.Expr(SynExpr.Paren _)::TS.Expr(NewObjectOrMethodCall(args))::_ -> 
                 match precedingArgument with
                 | None -> Some args
                 | Some e ->
@@ -836,20 +838,26 @@ module internal UntypedParseInfoImpl =
                         // new A($)
                         | SynExpr.Const(SynConst.Unit, m) when rangeContainsPos m pos ->
                             match path with
-                            | TS.Expr(NewObject args)::_ -> Some (CompletionContext.NewObject args)
-                            | _ -> defaultTraverse expr
+                            | TS.Expr(NewObjectOrMethodCall args)::_ -> 
+                                Some (CompletionContext.ParameterList args)
+                            | _ -> 
+                                defaultTraverse expr
                         // new (... A$)
                         | SynExpr.Ident id when id.idRange.End = pos ->
                             match path with
-                            | PartOfParameterList None args -> Some (CompletionContext.NewObject args)
-                            | _ -> defaultTraverse expr
+                            | PartOfParameterList None args -> 
+                                Some (CompletionContext.ParameterList args)
+                            | _ -> 
+                                defaultTraverse expr
                         // new (A$ = 1)
                         // new (A = 1,$)
                         | Setter id when id.idRange.End = pos || rangeBeforePos expr.Range pos ->
                             let precedingArgument = if id.idRange.End = pos then None else Some expr
                             match path with
-                            | PartOfParameterList precedingArgument args-> Some (CompletionContext.NewObject args)
-                            | _ -> defaultTraverse expr
+                            | PartOfParameterList precedingArgument args-> 
+                                Some (CompletionContext.ParameterList args)
+                            | _ -> 
+                                defaultTraverse expr
                         | _ -> defaultTraverse expr
 
                     member this.VisitRecordField(path, copyOpt, field) = 

src/fsharp/vs/ServiceUntypedParse.fsi

@@ -67,9 +67,9 @@ type internal CompletionContext =
     // completing records field
     | RecordField of RecordContext
     | RangeOperator
-    // completing property setters in constructor call
-    // end of constructor ast node * list of properties that were already set
-    | NewObject of pos * HashSet<string>
+    // completing named parameters\setters in parameter list of constructor\method calls
+    // end of name ast node * list of properties\parameters that were already set
+    | ParameterList of pos * HashSet<string>
 
 // implementation details used by other code in the compiler    
 module internal UntypedParseInfoImpl =

src/fsharp/vs/service.fs

@@ -598,13 +598,42 @@ type TypeCheckInfo
     let GetPreciseItemsFromNameResolutionVS(line,colAtEndOfNames,membersByResidue,filterCtors, resolveOverloads, hasTextChangedSinceLastTypecheck) = 
         GetPreciseItemsFromNameResolution(Pos.fromVS line colAtEndOfNames, membersByResidue, filterCtors, resolveOverloads, hasTextChangedSinceLastTypecheck)
 
-    let GetSettableFields endOfExprPos hasTextChangedSinceLastTypecheck =
+    let CollectParameters (methods: MethInfo list) amap m: Item list = 
+        methods
+        |> List.collect (fun meth ->
+            match meth.GetParamDatas(amap, m, meth.FormalMethodInst) with
+            | x::_ -> x |> List.choose(fun (ParamData(_isParamArray, _isOut, _optArgInfo, name, _, ty)) -> 
+                match name with
+                | Some n -> Some (Item.ArgName(Ident(n, m), ty, Some (ArgumentContainer.Method meth)))
+                | None -> None
+                )
+            | _ -> []
+        )
+
+    let GetNamedParametersAndSettableFields endOfExprPos hasTextChangedSinceLastTypecheck =
         let cnrs = GetCapturedNameResolutions endOfExprPos ResolveOverloads.No |> ResizeArray.toList |> List.rev
-        match cnrs with
-        | CNR(_, Item.CtorGroup(_, ctor::_), _, denv, nenv, ad, m)::_ ->
-            let result = ResolveCompletionsInType ncenv nenv ResolveCompletionTargets.SettablePropertiesAndFields m ad false ctor.EnclosingType
+        let result =
+            match cnrs with
+            | CNR(_, Item.CtorGroup(_, ((ctor::_) as ctors)), _, denv, nenv, ad, m)::_ ->
+                let props = ResolveCompletionsInType ncenv nenv ResolveCompletionTargets.SettablePropertiesAndFields m ad false ctor.EnclosingType
+                let parameters = CollectParameters ctors amap m
+                Some (denv, m, props @ parameters)
+            | CNR(_, Item.MethodGroup(_, methods), _, denv, nenv, ad, m)::_ ->
+                let props = 
+                    methods
+                    |> List.collect (fun meth ->
+                        let retTy = meth.GetFSharpReturnTy(amap, m, meth.FormalMethodInst)
+                        ResolveCompletionsInType ncenv nenv ResolveCompletionTargets.SettablePropertiesAndFields m ad false retTy
+                    )
+                let parameters = CollectParameters methods amap m
+                Some (denv, m, props @ parameters)
+            | _ -> 
+                None
+        match result with
+        | None -> 
+            NameResResult.Empty
+        | Some (denv, m, result) -> 
             ReturnItemsOfType result g denv m TypeNameResolutionFlag.ResolveTypeNamesToTypeRefs hasTextChangedSinceLastTypecheck NameResResult.Members
-        | _ -> NameResResult.Empty
     
     /// finds captured typing for the given position
     let GetExprTypingForPosition(endOfExprPos) = 
@@ -645,7 +674,6 @@ type TypeCheckInfo
             Some (items, denv, m)
         | _ -> None
 
-
     /// Looks at the exact expression types at the position to the left of the 
     /// residue then the source when it was typechecked.
     let GetPreciseCompletionListFromExprTypings(untypedParseInfo:UntypedParseInfo, line, colAtEndOfNames, filterCtors, hasTextChangedSinceLastTypecheck: (obj * Range -> bool)) = 
@@ -946,8 +974,8 @@ type TypeCheckInfo
         | Some(CompletionContext.RecordField(RecordContext.Constructor(typeName))) ->
             FindRecordFieldsInEnv([typeName], None)
             |> Some
-        | Some(NewObject (endPos, fields)) ->
-            let results = GetSettableFields endPos hasTextChangedSinceLastTypecheck
+        | Some(CompletionContext.ParameterList (endPos, fields)) ->
+            let results = GetNamedParametersAndSettableFields endPos hasTextChangedSinceLastTypecheck
 
             let declaredItems = getDeclaredItems false
 

vsintegration/src/unittests/Tests.LanguageService.Completion.fs

@@ -557,6 +557,65 @@ type AutoCompletionListTests() as this  =
         AssertCtrlSpaceCompleteContains (typeDef @ ["open Ext"; "A((**))"]) "A((**)" ["XYZ"] [] // positive
         AssertCtrlSpaceCompleteContains (typeDef @ ["A((**))"]) "A((**)" [] ["XYZ"] // negative
 
+    [<Test>]
+    [<Category("Completion in object initializer")>]
+    member public this.``ObjectInitializer.CompletionForNamedParameters``() =
+        let typeDef1 = 
+            [
+                "type A = "
+                "   static member Run(xyz: int, zyx: string) = 1"
+            ]
+        AssertCtrlSpaceCompleteContains (typeDef1 @ ["A.Run()"]) ".Run(" ["xyz"; "zyx"] [] 
+        AssertCtrlSpaceCompleteContains (typeDef1 @ ["A.Run(x = 1)"]) ".Run(x" ["xyz"] [] 
+        AssertCtrlSpaceCompleteContains (typeDef1 @ ["A.Run(x = 1,)"]) ".Run(x = 1," ["xyz"; "zyx"] [] 
+
+        let typeDef2 = 
+            [
+                "type A = "
+                "   static member Run<'T>(xyz: 'T, zyx: string) = 1"
+            ]
+        AssertCtrlSpaceCompleteContains (typeDef2 @ ["A.Run()"]) ".Run(" ["xyz"; "zyx"] [] 
+        AssertCtrlSpaceCompleteContains (typeDef2 @ ["A.Run(x = 1)"]) ".Run(x" ["xyz"] [] 
+        AssertCtrlSpaceCompleteContains (typeDef2 @ ["A.Run(x = 1,)"]) ".Run(x = 1," ["xyz"; "zyx"] [] 
+        AssertCtrlSpaceCompleteContains (typeDef2 @ ["A.Run<_>()"]) ".Run<_>(" ["xyz"; "zyx"] [] 
+        AssertCtrlSpaceCompleteContains (typeDef2 @ ["A.Run<_>(x = 1)"]) ".Run<_>(x" ["xyz"] [] 
+        AssertCtrlSpaceCompleteContains (typeDef2 @ ["A.Run<_>(x = 1,)"]) ".Run<_>(x = 1," ["xyz"; "zyx"] [] 
+    
+    [<Test>]
+    [<Category("Completion in object initializer")>]
+    member public this.``ObjectInitializer.CompletionForSettablePropertiesInReturnValue``() =
+        let typeDef1 = 
+            [
+                "type A0() = member val Settable0 = 1 with get,set"
+                "type A() = "
+                "   member val Settable = 1 with get,set"
+                "   member val NonSettable = 1"
+                "   static member Run(): A0 =  Unchecked.defaultof<_>"
+                "   static member Run(a: string): A =  Unchecked.defaultof<_>"
+            ]
+        AssertCtrlSpaceCompleteContains (typeDef1 @ ["A.Run()"]) ".Run(" ["Settable"; "Settable0"] ["NonSettable"] 
+        AssertCtrlSpaceCompleteContains (typeDef1 @ ["A.Run(S = 1)"]) ".Run(S" ["Settable"; "Settable0"] ["NonSettable"] 
+        AssertCtrlSpaceCompleteContains (typeDef1 @ ["A.Run(S = 1,)"]) ".Run(S = 1," ["Settable"; "Settable0"] ["NonSettable"]  
+        AssertCtrlSpaceCompleteContains (typeDef1 @ ["A.Run(Settable = 1,)"]) ".Run(Settable = 1," ["Settable0"] ["NonSettable"]  
+
+        let typeDef2 = 
+            [
+                "type A0() = member val Settable0 = 1 with get,set"
+                "type A() = "
+                "   member val Settable = 1 with get,set"
+                "   member val NonSettable = 1"
+                "   static member Run<'T>(): A0 = Unchecked.defaultof<_>"
+                "   static member Run(a: int): A = Unchecked.defaultof<_>"
+            ]
+        AssertCtrlSpaceCompleteContains (typeDef2 @ ["A.Run()"]) ".Run(" ["Settable"; "Settable0"] ["NonSettable"] 
+        AssertCtrlSpaceCompleteContains (typeDef2 @ ["A.Run(S = 1)"]) ".Run(S" ["Settable"; "Settable0"] ["NonSettable"] 
+        AssertCtrlSpaceCompleteContains (typeDef2 @ ["A.Run(S = 1,)"]) ".Run(S = 1," ["Settable"; "Settable0"] ["NonSettable"] 
+        AssertCtrlSpaceCompleteContains (typeDef2 @ ["A.Run(Settable = 1,)"]) ".Run(Settable = 1," ["Settable0"] ["NonSettable"] 
+        AssertCtrlSpaceCompleteContains (typeDef2 @ ["A.Run<_>()"]) ".Run<_>(" ["Settable"; "Settable0"] ["NonSettable"] 
+        AssertCtrlSpaceCompleteContains (typeDef2 @ ["A.Run<_>(S = 1)"]) ".Run<_>(S" ["Settable"; "Settable0"] ["NonSettable"] 
+        AssertCtrlSpaceCompleteContains (typeDef2 @ ["A.Run<_>(S = 1,)"]) ".Run<_>(S = 1," ["Settable"; "Settable0"] ["NonSettable"] 
+        AssertCtrlSpaceCompleteContains (typeDef2 @ ["A.Run<_>(Settable = 1,)"]) ".Run<_>(Settable = 1," ["Settable0"] ["NonSettable"] 
+
 
     [<Test>]
     [<Category("RangeOperator")>]