Better CE error reporting when using use! with and!

docs/release-notes/.FSharp.Compiler.Service/9.0.100.md

@@ -43,6 +43,7 @@
 * Applied nullable reference types to FSharp.Compiler.Service itself ([PR #15310](https://github.com/dotnet/fsharp/pull/15310))
 * Ensure that isinteractive multi-emit backing fields are not public. ([Issue #17439](https://github.com/dotnet/fsharp/issues/17438)), ([PR #17439](https://github.com/dotnet/fsharp/pull/17439))
 * Better error reporting for unions with duplicated fields. ([PR #17521](https://github.com/dotnet/fsharp/pull/17521))
+* Better CE error reporting when using `use!` with `and!` ([PR #17671](https://github.com/dotnet/fsharp/pull/17671))
 * Better error reporting for let bindings. ([PR #17601](https://github.com/dotnet/fsharp/pull/17601))
 * Optimize ILTypeDef interface impls reading from metadata. ([PR #17382](https://github.com/dotnet/fsharp/pull/17382))
 * Better error reporting for active patterns. ([PR #17666](https://github.com/dotnet/fsharp/pull/17666))

src/Compiler/Checking/Expressions/CheckComputationExpressions.fs

@@ -1987,12 +1987,17 @@ let rec TryTranslateComputationExpression
 
             Some(translatedCtxt bindExpr)
 
-        // 'use! pat = e1 ... in e2' where 'pat' is not a simple name --> error
+        // 'use! pat = e1 ... in e2' where 'pat' is not a simple name -> error
         | SynExpr.LetOrUseBang(isUse = true; pat = pat; andBangs = andBangs) ->
             if isNil andBangs then
                 error (Error(FSComp.SR.tcInvalidUseBangBinding (), pat.Range))
             else
-                error (Error(FSComp.SR.tcInvalidUseBangBindingNoAndBangs (), comp.Range))
+                let m =
+                    match andBangs with
+                    | [] -> comp.Range
+                    | h :: _ -> h.Trivia.AndBangKeyword
+
+                error (Error(FSComp.SR.tcInvalidUseBangBindingNoAndBangs (), m))
 
         // 'let! pat1 = expr1 and! pat2 = expr2 in ...' -->
         //     build.BindN(expr1, expr2, ...)

src/Compiler/SyntaxTree/SyntaxTree.fs

@@ -870,6 +870,14 @@ type SynExprAndBang =
         range: range *
         trivia: SynExprAndBangTrivia
 
+    member x.Range =
+        match x with
+        | SynExprAndBang(range = range) -> range
+
+    member this.Trivia =
+        match this with
+        | SynExprAndBang(trivia = trivia) -> trivia
+
 [<NoEquality; NoComparison>]
 type SynExprRecordField =
     | SynExprRecordField of

src/Compiler/SyntaxTree/SyntaxTree.fsi

@@ -982,6 +982,12 @@ type SynExprAndBang =
         range: range *
         trivia: SynExprAndBangTrivia
 
+    /// Gets the syntax range of this construct
+    member Range: range
+
+    /// Gets the trivia associated with this construct
+    member Trivia: SynExprAndBangTrivia
+
 [<NoEquality; NoComparison>]
 type SynExprRecordField =
     | SynExprRecordField of

src/Compiler/SyntaxTree/SyntaxTrivia.fs

@@ -270,6 +270,7 @@ type SynBindingTrivia =
 [<NoEquality; NoComparison>]
 type SynExprAndBangTrivia =
     {
+        AndBangKeyword: range
         EqualsRange: range
         InKeyword: range option
     }

src/Compiler/SyntaxTree/SyntaxTrivia.fsi

@@ -334,9 +334,10 @@ type SynBindingTrivia =
 [<NoEquality; NoComparison>]
 type SynExprAndBangTrivia =
     {
+        /// The syntax range of the `and!` keyword
+        AndBangKeyword: range
         /// The syntax range of the `=` token.
         EqualsRange: range
-
         /// The syntax range of the `in` keyword.
         InKeyword: range option
     }

src/Compiler/pars.fsy

@@ -4078,15 +4078,17 @@ moreBinders:
        let mEquals = rhs parseState 3
        let m = unionRanges (rhs parseState 1) $4.Range
        let mIn = rhs parseState 5
-       SynExprAndBang(spBind, $1, true, $2, $4, m, { EqualsRange = mEquals; InKeyword = Some mIn }) :: $6 }
+       let trivia = { AndBangKeyword = rhs parseState 1; EqualsRange = mEquals; InKeyword = Some mIn }
+       SynExprAndBang(spBind, $1, true, $2, $4, m, trivia) :: $6 }
 
   | OAND_BANG headBindingPattern EQUALS typedSequentialExprBlock hardwhiteDefnBindingsTerminator opt_OBLOCKSEP moreBinders %prec expr_let
      { let report, mIn, _ = $5
        report "and!" (rhs parseState 1)  // report unterminated error
        let spBind = DebugPointAtBinding.Yes(rhs2 parseState 1 5) (* TODO Pretty sure this is wrong *)
        let mEquals = rhs parseState 3
        let m = unionRanges (rhs parseState 1) $4.Range
-       SynExprAndBang(spBind, $1, true, $2, $4, m, { EqualsRange = mEquals; InKeyword = mIn }) :: $7 }
+       let trivia = { AndBangKeyword = rhs parseState 1; EqualsRange = mEquals; InKeyword = mIn }
+       SynExprAndBang(spBind, $1, true, $2, $4, m, trivia) :: $7 }
 
   | %prec prec_no_more_attr_bindings
       { [] }

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

@@ -152,3 +152,98 @@ let x = A.Prop { return 0 }
         |> compile
         |> shouldSucceed
         |> ignore
+
+    [<Fact>]
+    let ``use! may not be combined with and!`` () =
+        Fsx """
+module Result =
+    let zip x1 x2 =
+        match x1,x2 with
+        | Ok x1res, Ok x2res -> Ok (x1res, x2res)
+        | Error e, _ -> Error e
+        | _, Error e -> Error e
+
+type ResultBuilder() =
+    member _.MergeSources(t1: Result<'T,'U>, t2: Result<'T1,'U>) = Result.zip t1 t2
+    member _.BindReturn(x: Result<'T,'U>, f) = Result.map f x
+
+let result = ResultBuilder()
+
+let run r2 r3 =
+    result {
+        use! b = r2
+        and! c = r3
+        return b - c
+    }
+        """
+        |> ignoreWarnings
+        |> typecheck
+        |> shouldFail
+        |> withDiagnostics [
+            (Error 3345, Line 18, Col 9, Line 18, Col 13, "use! may not be combined with and!")
+        ]
+
+    [<Fact>]
+    let ``multiple use! may not be combined with and!`` () =
+        Fsx """
+module Result =
+    let zip x1 x2 =
+        match x1,x2 with
+        | Ok x1res, Ok x2res -> Ok (x1res, x2res)
+        | Error e, _ -> Error e
+        | _, Error e -> Error e
+
+type ResultBuilder() =
+    member _.MergeSources(t1: Result<'T,'U>, t2: Result<'T1,'U>) = Result.zip t1 t2
+    member _.BindReturn(x: Result<'T,'U>, f) = Result.map f x
+
+let result = ResultBuilder()
+
+let run r2 r3 =
+    result {
+        use! b = r2
+        and! c = r3
+        use! d = r2
+        return b - c
+    }
+        """
+        |> ignoreWarnings
+        |> typecheck
+        |> shouldFail
+        |> withDiagnostics [
+            (Error 3345, Line 18, Col 9, Line 18, Col 13, "use! may not be combined with and!")
+        ]
+
+    [<Fact>]
+    let ``multiple use! may not be combined with multiple and!`` () =
+        Fsx """
+module Result =
+    let zip x1 x2 =
+        match x1,x2 with
+        | Ok x1res, Ok x2res -> Ok (x1res, x2res)
+        | Error e, _ -> Error e
+        | _, Error e -> Error e
+
+type ResultBuilder() =
+    member _.MergeSources(t1: Result<'T,'U>, t2: Result<'T1,'U>) = Result.zip t1 t2
+    member _.BindReturn(x: Result<'T,'U>, f) = Result.map f x
+    member _.BindReturn(x: Result<'T,'U>, f) = Result.map f x
+    member _.Bind(x: Result<'T,'U>, f) = Result.bind f x
+
+let result = ResultBuilder()
+
+let run r2 r3 =
+    result {
+        let! c = r3
+        and! c = r3
+        use! b = r2
+        and! c = r3
+        return b - c
+    }
+        """
+        |> ignoreWarnings
+        |> typecheck
+        |> shouldFail
+        |> withDiagnostics [
+            (Error 3345, Line 22, Col 9, Line 22, Col 13, "use! may not be combined with and!")
+        ]

tests/FSharp.Compiler.Service.Tests/FSharp.Compiler.Service.SurfaceArea.netstandard20.debug.bsl

@@ -7740,8 +7740,12 @@ FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.Syntax.SynExpr get_body()
 FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.Syntax.SynExprAndBang NewSynExprAndBang(FSharp.Compiler.Syntax.DebugPointAtBinding, Boolean, Boolean, FSharp.Compiler.Syntax.SynPat, FSharp.Compiler.Syntax.SynExpr, FSharp.Compiler.Text.Range, FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia)
 FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.Syntax.SynPat get_pat()
 FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.Syntax.SynPat pat
+FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia Trivia
+FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia get_Trivia()
 FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia get_trivia()
 FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia trivia
+FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.Text.Range Range
+FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.Text.Range get_Range()
 FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.Text.Range get_range()
 FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.Text.Range range
 FSharp.Compiler.Syntax.SynExprAndBang: Int32 Tag
@@ -10139,12 +10143,14 @@ FSharp.Compiler.SyntaxTrivia.SynEnumCaseTrivia: Microsoft.FSharp.Core.FSharpOpti
 FSharp.Compiler.SyntaxTrivia.SynEnumCaseTrivia: Microsoft.FSharp.Core.FSharpOption`1[FSharp.Compiler.Text.Range] get_BarRange()
 FSharp.Compiler.SyntaxTrivia.SynEnumCaseTrivia: System.String ToString()
 FSharp.Compiler.SyntaxTrivia.SynEnumCaseTrivia: Void .ctor(Microsoft.FSharp.Core.FSharpOption`1[FSharp.Compiler.Text.Range], FSharp.Compiler.Text.Range)
+FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia: FSharp.Compiler.Text.Range AndBangKeyword
 FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia: FSharp.Compiler.Text.Range EqualsRange
+FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia: FSharp.Compiler.Text.Range get_AndBangKeyword()
 FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia: FSharp.Compiler.Text.Range get_EqualsRange()
 FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia: Microsoft.FSharp.Core.FSharpOption`1[FSharp.Compiler.Text.Range] InKeyword
 FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia: Microsoft.FSharp.Core.FSharpOption`1[FSharp.Compiler.Text.Range] get_InKeyword()
 FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia: System.String ToString()
-FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia: Void .ctor(FSharp.Compiler.Text.Range, Microsoft.FSharp.Core.FSharpOption`1[FSharp.Compiler.Text.Range])
+FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia: Void .ctor(FSharp.Compiler.Text.Range, FSharp.Compiler.Text.Range, Microsoft.FSharp.Core.FSharpOption`1[FSharp.Compiler.Text.Range])
 FSharp.Compiler.SyntaxTrivia.SynExprAnonRecdTrivia: FSharp.Compiler.Text.Range OpeningBraceRange
 FSharp.Compiler.SyntaxTrivia.SynExprAnonRecdTrivia: FSharp.Compiler.Text.Range get_OpeningBraceRange()
 FSharp.Compiler.SyntaxTrivia.SynExprAnonRecdTrivia: System.String ToString()

tests/FSharp.Compiler.Service.Tests/FSharp.Compiler.Service.SurfaceArea.netstandard20.release.bsl

@@ -7740,8 +7740,12 @@ FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.Syntax.SynExpr get_body()
 FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.Syntax.SynExprAndBang NewSynExprAndBang(FSharp.Compiler.Syntax.DebugPointAtBinding, Boolean, Boolean, FSharp.Compiler.Syntax.SynPat, FSharp.Compiler.Syntax.SynExpr, FSharp.Compiler.Text.Range, FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia)
 FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.Syntax.SynPat get_pat()
 FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.Syntax.SynPat pat
+FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia Trivia
+FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia get_Trivia()
 FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia get_trivia()
 FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia trivia
+FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.Text.Range Range
+FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.Text.Range get_Range()
 FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.Text.Range get_range()
 FSharp.Compiler.Syntax.SynExprAndBang: FSharp.Compiler.Text.Range range
 FSharp.Compiler.Syntax.SynExprAndBang: Int32 Tag
@@ -10139,12 +10143,14 @@ FSharp.Compiler.SyntaxTrivia.SynEnumCaseTrivia: Microsoft.FSharp.Core.FSharpOpti
 FSharp.Compiler.SyntaxTrivia.SynEnumCaseTrivia: Microsoft.FSharp.Core.FSharpOption`1[FSharp.Compiler.Text.Range] get_BarRange()
 FSharp.Compiler.SyntaxTrivia.SynEnumCaseTrivia: System.String ToString()
 FSharp.Compiler.SyntaxTrivia.SynEnumCaseTrivia: Void .ctor(Microsoft.FSharp.Core.FSharpOption`1[FSharp.Compiler.Text.Range], FSharp.Compiler.Text.Range)
+FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia: FSharp.Compiler.Text.Range AndBangKeyword
 FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia: FSharp.Compiler.Text.Range EqualsRange
+FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia: FSharp.Compiler.Text.Range get_AndBangKeyword()
 FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia: FSharp.Compiler.Text.Range get_EqualsRange()
 FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia: Microsoft.FSharp.Core.FSharpOption`1[FSharp.Compiler.Text.Range] InKeyword
 FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia: Microsoft.FSharp.Core.FSharpOption`1[FSharp.Compiler.Text.Range] get_InKeyword()
 FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia: System.String ToString()
-FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia: Void .ctor(FSharp.Compiler.Text.Range, Microsoft.FSharp.Core.FSharpOption`1[FSharp.Compiler.Text.Range])
+FSharp.Compiler.SyntaxTrivia.SynExprAndBangTrivia: Void .ctor(FSharp.Compiler.Text.Range, FSharp.Compiler.Text.Range, Microsoft.FSharp.Core.FSharpOption`1[FSharp.Compiler.Text.Range])
 FSharp.Compiler.SyntaxTrivia.SynExprAnonRecdTrivia: FSharp.Compiler.Text.Range OpeningBraceRange
 FSharp.Compiler.SyntaxTrivia.SynExprAnonRecdTrivia: FSharp.Compiler.Text.Range get_OpeningBraceRange()
 FSharp.Compiler.SyntaxTrivia.SynExprAnonRecdTrivia: System.String ToString()

tests/service/data/SyntaxTree/ComputationExpression/MultipleSynExprAndBangHaveRangeThatStartsAtAndAndEndsAfterExpression.fs.bsl

@@ -26,7 +26,8 @@ ImplFile
                            App
                              (NonAtomic, false, Ident getFoo,
                               Const (Unit, (4,22--4,24)), (4,15--4,24)),
-                           (4,4--4,24), { EqualsRange = (4,13--4,14)
+                           (4,4--4,24), { AndBangKeyword = (4,4--4,8)
+                                          EqualsRange = (4,13--4,14)
                                           InKeyword = Some (4,25--4,27) });
                         SynExprAndBang
                           (Yes (5,4--6,10), false, true,
@@ -35,7 +36,8 @@ ImplFile
                            App
                              (NonAtomic, false, Ident getMeh,
                               Const (Unit, (5,22--5,24)), (5,15--5,24)),
-                           (5,4--5,24), { EqualsRange = (5,13--5,14)
+                           (5,4--5,24), { AndBangKeyword = (5,4--5,8)
+                                          EqualsRange = (5,13--5,14)
                                           InKeyword = None })],
                        YieldOrReturn ((false, true), Ident bar, (6,4--6,14)),
                        (3,4--6,14), { EqualsRange = Some (3,13--3,14) }),

tests/service/data/SyntaxTree/ComputationExpression/SynExprAndBangRangeStartsAtAndAndEndsAfterExpression.fs.bsl

@@ -25,7 +25,8 @@ ImplFile
                            App
                              (NonAtomic, false, Ident getFoo,
                               Const (Unit, (5,22--5,24)), (5,15--5,24)),
-                           (5,4--5,24), { EqualsRange = (5,13--5,14)
+                           (5,4--5,24), { AndBangKeyword = (5,4--5,8)
+                                          EqualsRange = (5,13--5,14)
                                           InKeyword = None })],
                        YieldOrReturn ((false, true), Ident bar, (7,4--7,14)),
                        (3,4--7,14), { EqualsRange = Some (3,13--3,14) }),

tests/service/data/SyntaxTree/Expression/SynExprLetOrUseBangContainsTheRangeOfTheEqualsSign.fs.bsl

@@ -22,7 +22,8 @@ ImplFile
                            App
                              (NonAtomic, false, Ident someFunction,
                               Const (Unit, (4,26--4,28)), (4,13--4,28)),
-                           (4,4--4,28), { EqualsRange = (4,11--4,12)
+                           (4,4--4,28), { AndBangKeyword = (4,4--4,8)
+                                          EqualsRange = (4,11--4,12)
                                           InKeyword = None })],
                        YieldOrReturn
                          ((false, true), Const (Unit, (5,11--5,13)), (5,4--5,13)),