Operator syntax tree two

src/fsharp/CheckComputationExpressions.fs

@@ -639,10 +639,10 @@ let TcComputationExpression (cenv: cenv) env (overallTy: OverallTy) tpenv (mWhol
         match e with 
         | ForEachThen (isFromSource, firstSourcePat, firstSource, JoinOrGroupJoinOrZipClause(nm, secondSourcePat, secondSource, keySelectorsOpt, pat3opt, mOpCore), innerComp) 
             when 
-               (let _firstSourceSimplePats, later1 = 
-                    use _holder = TemporarilySuspendReportingTypecheckResultsToSink cenv.tcSink
-                    SimplePatsOfPat cenv.synArgNameGenerator firstSourcePat 
-                Option.isNone later1)
+               (use _holder = TemporarilySuspendReportingTypecheckResultsToSink cenv.tcSink
+                match firstSourcePat with
+                | SynPat.Named _ -> true
+                | _ -> SimplePatsOfPat cenv.synArgNameGenerator firstSourcePat |> snd |> Option.isNone)
 
              -> Some (isFromSource, firstSourcePat, firstSource, nm, secondSourcePat, secondSource, keySelectorsOpt, pat3opt, mOpCore, innerComp)
 
@@ -828,7 +828,12 @@ let TcComputationExpression (cenv: cenv) env (overallTy: OverallTy) tpenv (mWhol
                         vspecs, envinner)
                 | None -> varSpace
 
-            let firstSourceSimplePats, later1 = SimplePatsOfPat cenv.synArgNameGenerator firstSourcePat 
+            let firstSourceSimplePats, later1 =
+                match firstSourcePat with
+                | SynPat.Named (v, thisV, _, m) ->
+                    SynSimplePats.SimplePats ([SynSimplePat.Id (v, None, false, thisV, false, m)], m), None
+                | _ ->
+                    SimplePatsOfPat cenv.synArgNameGenerator firstSourcePat 
             let secondSourceSimplePats, later2 = SimplePatsOfPat cenv.synArgNameGenerator secondSourcePat
 
             if Option.isSome later1 then errorR (Error (FSComp.SR.tcJoinMustUseSimplePattern(nm.idText), firstSourcePat.Range))

src/fsharp/CheckDeclarations.fs

@@ -4830,8 +4830,8 @@ module TcDeclarations =
                         // Only the keep the field-targeted attributes
                         let attribs = attribs |> List.filter (fun a -> match a.Target with Some t when t.idText = "field" -> true | _ -> false)
                         let mLetPortion = synExpr.Range
-                        let fldId = ident (CompilerGeneratedName id.idText, mLetPortion)
-                        let headPat = SynPat.LongIdent (LongIdentWithDots([fldId], []), None, None, Some noInferredTypars, SynArgPats.Pats [], None, mLetPortion)
+                        let fldPat = SynPat.Named(ident (CompilerGeneratedName id.idText, mLetPortion), false, None, mLetPortion)
+                        let headPat = SynPat.ParametersOwner (fldPat, None, None, Some noInferredTypars, SynArgPats.Pats [], None, mLetPortion)
                         let retInfo = match tyOpt with None -> None | Some ty -> Some (SynReturnInfo((ty, SynInfo.unnamedRetVal), ty.Range))
                         let isMutable = 
                             match propKind with 
@@ -4858,8 +4858,8 @@ module TcDeclarations =
                         // Only the keep the non-field-targeted attributes
                         let attribs = attribs |> List.filter (fun a -> match a.Target with Some t when t.idText = "field" -> false | _ -> true)
                         let fldId = ident (CompilerGeneratedName id.idText, mMemberPortion)
-                        let headPatIds = if isStatic then [id] else [ident ("__", mMemberPortion);id]
-                        let headPat = SynPat.LongIdent (LongIdentWithDots(headPatIds, []), None, None, Some noInferredTypars, SynArgPats.Pats [], None, mMemberPortion)
+                        let headPatIdPat = if isStatic then SynPat.Named(id, false, None, id.idRange) else SynPat.LongIdent(LongIdentWithDots([ident ("__", mMemberPortion);id], []), None, unionRanges mMemberPortion id.idRange)
+                        let headPat = SynPat.ParametersOwner (headPatIdPat, None, None, Some noInferredTypars, SynArgPats.Pats [], None, mMemberPortion)
 
                         match propKind, mGetSetOpt with 
                         | SynMemberKind.PropertySet, Some m -> errorR(Error(FSComp.SR.parsMutableOnAutoPropertyShouldBeGetSetNotJustSet(), m))
@@ -4884,7 +4884,7 @@ module TcDeclarations =
                             | SynMemberKind.PropertyGetSet -> 
                                 let setter = 
                                     let vId = ident("v", mMemberPortion)
-                                    let headPat = SynPat.LongIdent (LongIdentWithDots(headPatIds, []), None, None, Some noInferredTypars, SynArgPats.Pats [mkSynPatVar None vId], None, mMemberPortion)
+                                    let headPat = SynPat.ParametersOwner (headPatIdPat, None, None, Some noInferredTypars, SynArgPats.Pats [mkSynPatVar None vId], None, mMemberPortion)
                                     let rhsExpr = mkSynAssign (SynExpr.Ident fldId) (SynExpr.Ident vId)
                                     //let retInfo = match tyOpt with None -> None | Some ty -> Some (SynReturnInfo((ty, SynInfo.unnamedRetVal), ty.Range))
                                     let binding = mkSynBinding (xmlDoc, headPat) (access, false, false, mMemberPortion, DebugPointAtBinding.NoneAtInvisible, None, rhsExpr, rhsExpr.Range, [], [], Some (memberFlags SynMemberKind.PropertySet), SynBindingTrivia.Zero)