Parser: recover on missing expressions after rArrow

src/Compiler/pars.fsy

@@ -3440,10 +3440,13 @@ declExprBlock:
 /* for these it only inserts a trailing ORIGHT_BLOCK_END */
 typedSequentialExprBlockR: 
   | typedSequentialExpr ORIGHT_BLOCK_END
-    { $1 }
+    { fun _ -> $1 }
 
   | typedSequentialExpr
-    { $1 }
+    { fun _ -> $1 }
+
+  | recover
+    { fun mStart -> arbExpr ("typedSequentialExprBlockR", mStart) }
 
 typedSequentialExpr: 
   | sequentialExpr COLON typeWithTypeConstraints
@@ -3573,36 +3576,49 @@ declExpr:
       { if not $3 then reportParseErrorAt (rhs parseState 1) (FSComp.SR.parsUnexpectedEndOfFileMatch())
         // Produce approximate expression during error recovery 
         exprFromParseError $2 }
-
-  | TRY typedSequentialExprBlockR withClauses              %prec expr_try 
-      { let mTry = (rhs parseState 1)
+
+  | TRY typedSequentialExprBlockR withClauses %prec expr_try 
+      { let mTry = rhs parseState 1
+        let expr = $2 mTry
         let spTry = DebugPointAtTry.Yes mTry
-        let mWith, (clauses, mLast) = $3 
+        let mWith, (clauses, mLast) = $3
         let spWith = DebugPointAtWith.Yes mWith
-        let mTryToWith = unionRanges mTry mWith 
-        let mWithToLast = unionRanges mWith mLast 
+        let mTryToWith = unionRanges mTry mWith
+        let mWithToLast = unionRanges mWith mLast
         let mTryToLast = unionRanges mTry mLast
-        let trivia: SynExprTryWithTrivia = 
+        let trivia: SynExprTryWithTrivia =
             { TryKeyword = mTry
               TryToWithRange = mTryToWith
               WithKeyword = mWith
               WithToEndRange = mWithToLast }
-        SynExpr.TryWith ($2, clauses, mTryToLast, spTry, spWith, trivia) }
-
-  | TRY typedSequentialExprBlockR recover              %prec expr_try 
-      { // Produce approximate expression during error recovery 
-        // Include any expressions to make sure they gets type checked in case that generates useful results for intellisense 
-        if not $3 then reportParseErrorAt (rhs parseState 1) (FSComp.SR.parsUnexpectedEndOfFileTry())
-        exprFromParseError $2 }
+        SynExpr.TryWith (expr, clauses, mTryToLast, spTry, spWith, trivia) }
 
-  | TRY typedSequentialExprBlockR FINALLY typedSequentialExprBlock %prec expr_try 
-      { let mTry = rhs parseState 1 
+  | TRY typedSequentialExprBlockR recover %prec expr_try
+      { let mTry = rhs parseState 1
+        let spTry = DebugPointAtTry.Yes mTry
+        if not $3 then reportParseErrorAt mTry (FSComp.SR.parsUnexpectedEndOfFileTry ())
+        let expr = $2 mTry
+        let mExpr = expr.Range
+        let mEnd = mExpr.EndRange
+        let spWith = DebugPointAtWith.Yes mEnd
+        let mWhole = unionRanges mTry mEnd
+        let trivia: SynExprTryWithTrivia =
+            { TryKeyword = mTry
+              TryToWithRange = mWhole
+              WithKeyword = mEnd
+              WithToEndRange = mWhole }
+        SynExpr.TryWith (expr, [], mWhole, spTry, spWith, trivia) }
+
+  | TRY typedSequentialExprBlockR FINALLY typedSequentialExprBlock %prec expr_try
+      { let mTry = rhs parseState 1
+        let tryExpr = $2 mTry
         let spTry = DebugPointAtTry.Yes mTry
         let mFinally = rhs parseState 3
+        let finallyExpr = $4
         let spFinally = DebugPointAtFinally.Yes mFinally
-        let mTryToLast = unionRanges mTry $4.Range 
+        let mTryToLast = unionRanges mTry finallyExpr.Range
         let trivia = { TryKeyword = mTry; FinallyKeyword = mFinally }
-        SynExpr.TryFinally ($2, $4, mTryToLast, spTry, spFinally, trivia) }
+        SynExpr.TryFinally (tryExpr, finallyExpr, mTryToLast, spTry, spFinally, trivia) }
 
   | IF declExpr ifExprCases %prec expr_if 
       { let mIf = rhs parseState 1
@@ -3856,9 +3872,11 @@ declExpr:
   | FIXED declExpr
      { SynExpr.Fixed ($2, (unionRanges (rhs parseState 1) $2.Range)) } 
 
-  | RARROW typedSequentialExprBlockR 
-     { errorR(Error(FSComp.SR.parsArrowUseIsLimited(), lhs parseState))
-       SynExpr.YieldOrReturn ((true, true), $2, (unionRanges (rhs parseState 1) $2.Range)) } 
+  | RARROW typedSequentialExprBlockR
+     { errorR(Error(FSComp.SR.parsArrowUseIsLimited(), lhs parseState)) 
+       let mArrow = rhs parseState 1
+       let expr = $2 mArrow
+       SynExpr.YieldOrReturn ((true, true), expr, (unionRanges mArrow expr.Range)) }
 
   | declExpr COLON_QMARK typ
      { SynExpr.TypeTest ($1, $3, unionRanges $1.Range $3.Range) }
@@ -4156,11 +4174,12 @@ patternGuard:
   | /* EMPTY */
      { None }
 
-patternResult: 
-  | RARROW typedSequentialExprBlockR  
-     { let mArrow = rhs parseState 1
-       mArrow, $2 }
-
+patternResult:
+  | RARROW typedSequentialExprBlockR
+      { let mArrow = rhs parseState 1
+        let expr = $2 mArrow
+        mArrow, expr }
+
 ifExprCases: 
   | ifExprThen ifExprElifs 
       { let exprThen, mThen = $1
@@ -4667,8 +4686,10 @@ computationExpr:
      { $1.Range, (fun mLhs -> SynExpr.ComputationExpr (false, $1, mLhs)) }
 
 arrowThenExprR:
-  | RARROW typedSequentialExprBlockR 
-     { SynExpr.YieldOrReturn ((true, false), $2, unionRanges (rhs parseState 1) $2.Range) }
+  | RARROW typedSequentialExprBlockR
+      { let mArrow = rhs parseState 1
+        let expr = $2 mArrow
+        SynExpr.YieldOrReturn ((true, false), expr, unionRanges mArrow expr.Range) }
 
 forLoopBinder: 
   | parenPattern IN declExpr 
@@ -5009,15 +5030,17 @@ anonLambdaExpr:
        mkSynFunMatchLambdas parseState.SynArgNameGenerator false mAll $2 mArrow (arbExpr("anonLambdaExpr1", (rhs parseState 4))) }
 
   | OFUN atomicPatterns RARROW typedSequentialExprBlockR OEND
-     { let mAll = unionRanges (rhs parseState 1) $4.Range
-       let mArrow = Some (rhs parseState 3)
-       mkSynFunMatchLambdas parseState.SynArgNameGenerator false mAll $2 mArrow $4 }
+      { let mArrow = rhs parseState 3
+        let expr = $4 mArrow
+        let mAll = unionRanges (rhs parseState 1) expr.Range
+        mkSynFunMatchLambdas parseState.SynArgNameGenerator false mAll $2 (Some mArrow) expr }
 
   | OFUN atomicPatterns RARROW typedSequentialExprBlockR recover
-     { if not $5 then reportParseErrorAt (rhs parseState 1) (FSComp.SR.parsUnexpectedEndOfFileFunBody());
-       let mAll = unionRanges (rhs parseState 1) $4.Range
-       let mArrow = Some (rhs parseState 3)
-       exprFromParseError (mkSynFunMatchLambdas parseState.SynArgNameGenerator false mAll $2 mArrow $4) }
+     { if not $5 then reportParseErrorAt (rhs parseState 1) (FSComp.SR.parsUnexpectedEndOfFileFunBody ())
+       let mArrow = rhs parseState 3
+       let expr = $4 mArrow
+       let mAll = unionRanges (rhs parseState 1) expr.Range
+       exprFromParseError (mkSynFunMatchLambdas parseState.SynArgNameGenerator false mAll $2 (Some mArrow) expr) }
 
   | OFUN atomicPatterns RARROW ORIGHT_BLOCK_END OEND
      { let mLambda = rhs2 parseState 1 3

tests/service/data/SyntaxTree/Expression/Lambda - Missing expr 01.fs

@@ -0,0 +1,3 @@
+module Module
+
+(fun _ -> )

tests/service/data/SyntaxTree/Expression/Lambda - Missing expr 01.fs.bsl

@@ -0,0 +1,25 @@
+ImplFile
+  (ParsedImplFileInput
+     ("/root/Expression/Lambda - Missing expr 01.fs", false,
+      QualifiedNameOfFile Module, [], [],
+      [SynModuleOrNamespace
+         ([Module], false, NamedModule,
+          [Expr
+             (Paren
+                (Lambda
+                   (false, false,
+                    SimplePats
+                      ([Id (_arg1, None, true, false, false, (3,5--3,6))],
+                       (3,5--3,6)),
+                    ArbitraryAfterError ("anonLambdaExpr2", (3,9--3,9)),
+                    Some
+                      ([Wild (3,5--3,6)],
+                       ArbitraryAfterError ("anonLambdaExpr2", (3,9--3,9))),
+                    (3,1--3,9), { ArrowRange = Some (3,7--3,9) }), (3,0--3,1),
+                 Some (3,10--3,11), (3,0--3,11)), (3,0--3,11))],
+          PreXmlDoc ((1,0), FSharp.Compiler.Xml.XmlDocCollector), [], None,
+          (1,0--3,11), { LeadingKeyword = Module (1,0--1,6) })], (true, true),
+      { ConditionalDirectives = []
+        CodeComments = [] }, set []))
+
+(3,1)-(3,9) parse error Missing function body

tests/service/data/SyntaxTree/Expression/Lambda - Missing expr 02.fs

@@ -0,0 +1,3 @@
+module Module
+
+fun _ ->

tests/service/data/SyntaxTree/Expression/Lambda - Missing expr 02.fs.bsl

@@ -0,0 +1,24 @@
+ImplFile
+  (ParsedImplFileInput
+     ("/root/Expression/Lambda - Missing expr 02.fs", false,
+      QualifiedNameOfFile Module, [], [],
+      [SynModuleOrNamespace
+         ([Module], false, NamedModule,
+          [Expr
+             (Lambda
+                (false, false,
+                 SimplePats
+                   ([Id (_arg1, None, true, false, false, (3,4--3,5))],
+                    (3,4--3,5)),
+                 ArbitraryAfterError ("anonLambdaExpr2", (3,8--3,8)),
+                 Some
+                   ([Wild (3,4--3,5)],
+                    ArbitraryAfterError ("anonLambdaExpr2", (3,8--3,8))),
+                 (3,0--3,8), { ArrowRange = Some (3,6--3,8) }), (3,0--3,8))],
+          PreXmlDoc ((1,0), FSharp.Compiler.Xml.XmlDocCollector), [], None,
+          (1,0--3,8), { LeadingKeyword = Module (1,0--1,6) })], (true, true),
+      { ConditionalDirectives = []
+        CodeComments = [] }, set []))
+
+(4,0)-(4,0) parse warning Possible incorrect indentation: this token is offside of context started at position (1:1). Try indenting this token further or using standard formatting conventions.
+(3,0)-(3,8) parse error Missing function body

tests/service/data/SyntaxTree/Expression/Lambda 01.fs

@@ -0,0 +1,3 @@
+module Module
+
+(fun _ -> ())

tests/service/data/SyntaxTree/Expression/Lambda 01.fs.bsl

@@ -0,0 +1,19 @@
+ImplFile
+  (ParsedImplFileInput
+     ("/root/Expression/Lambda 01.fs", false, QualifiedNameOfFile Module, [], [],
+      [SynModuleOrNamespace
+         ([Module], false, NamedModule,
+          [Expr
+             (Paren
+                (Lambda
+                   (false, false,
+                    SimplePats
+                      ([Id (_arg1, None, true, false, false, (3,5--3,6))],
+                       (3,5--3,6)), Const (Unit, (3,10--3,12)),
+                    Some ([Wild (3,5--3,6)], Const (Unit, (3,10--3,12))),
+                    (3,1--3,12), { ArrowRange = Some (3,7--3,9) }), (3,0--3,1),
+                 Some (3,12--3,13), (3,0--3,13)), (3,0--3,13))],
+          PreXmlDoc ((1,0), FSharp.Compiler.Xml.XmlDocCollector), [], None,
+          (1,0--3,13), { LeadingKeyword = Module (1,0--1,6) })], (true, true),
+      { ConditionalDirectives = []
+        CodeComments = [] }, set []))

tests/service/data/SyntaxTree/Expression/Lambda 02.fs

@@ -0,0 +1,3 @@
+module Module
+
+fun _ -> ()

tests/service/data/SyntaxTree/Expression/Lambda 02.fs.bsl

@@ -0,0 +1,17 @@
+ImplFile
+  (ParsedImplFileInput
+     ("/root/Expression/Lambda 02.fs", false, QualifiedNameOfFile Module, [], [],
+      [SynModuleOrNamespace
+         ([Module], false, NamedModule,
+          [Expr
+             (Lambda
+                (false, false,
+                 SimplePats
+                   ([Id (_arg1, None, true, false, false, (3,4--3,5))],
+                    (3,4--3,5)), Const (Unit, (3,9--3,11)),
+                 Some ([Wild (3,4--3,5)], Const (Unit, (3,9--3,11))),
+                 (3,0--3,11), { ArrowRange = Some (3,6--3,8) }), (3,0--3,11))],
+          PreXmlDoc ((1,0), FSharp.Compiler.Xml.XmlDocCollector), [], None,
+          (1,0--3,11), { LeadingKeyword = Module (1,0--1,6) })], (true, true),
+      { ConditionalDirectives = []
+        CodeComments = [] }, set []))

tests/service/data/SyntaxTree/Expression/List - Comprehension 01.fs

@@ -0,0 +1,3 @@
+module Module
+
+[ for x in [] -> () ]

tests/service/data/SyntaxTree/Expression/List - Comprehension 01.fs.bsl

@@ -0,0 +1,20 @@
+ImplFile
+  (ParsedImplFileInput
+     ("/root/Expression/List - Comprehension 01.fs", false,
+      QualifiedNameOfFile Module, [], [],
+      [SynModuleOrNamespace
+         ([Module], false, NamedModule,
+          [Expr
+             (ArrayOrListComputed
+                (false,
+                 ForEach
+                   (Yes (3,2--3,5), Yes (3,8--3,10), SeqExprOnly true, true,
+                    Named (SynIdent (x, None), false, None, (3,6--3,7)),
+                    ArrayOrList (false, [], (3,11--3,13)),
+                    YieldOrReturn
+                      ((true, false), Const (Unit, (3,17--3,19)), (3,14--3,19)),
+                    (3,2--3,19)), (3,0--3,21)), (3,0--3,21))],
+          PreXmlDoc ((1,0), FSharp.Compiler.Xml.XmlDocCollector), [], None,
+          (1,0--3,21), { LeadingKeyword = Module (1,0--1,6) })], (true, true),
+      { ConditionalDirectives = []
+        CodeComments = [] }, set []))

tests/service/data/SyntaxTree/Expression/List - Comprehension 02.fs

@@ -0,0 +1,3 @@
+module Module
+
+[ for x in [] -> ]

tests/service/data/SyntaxTree/Expression/List - Comprehension 02.fs.bsl

@@ -0,0 +1,24 @@
+ImplFile
+  (ParsedImplFileInput
+     ("/root/Expression/List - Comprehension 02.fs", false,
+      QualifiedNameOfFile Module, [], [],
+      [SynModuleOrNamespace
+         ([Module], false, NamedModule,
+          [Expr
+             (ArrayOrListComputed
+                (false,
+                 ForEach
+                   (Yes (3,2--3,5), Yes (3,8--3,10), SeqExprOnly true, true,
+                    Named (SynIdent (x, None), false, None, (3,6--3,7)),
+                    ArrayOrList (false, [], (3,11--3,13)),
+                    YieldOrReturn
+                      ((true, false),
+                       ArbitraryAfterError
+                         ("typedSequentialExprBlockR", (3,14--3,16)),
+                       (3,14--3,16)), (3,2--3,16)), (3,0--3,18)), (3,0--3,18))],
+          PreXmlDoc ((1,0), FSharp.Compiler.Xml.XmlDocCollector), [], None,
+          (1,0--3,18), { LeadingKeyword = Module (1,0--1,6) })], (true, true),
+      { ConditionalDirectives = []
+        CodeComments = [] }, set []))
+
+(3,17)-(3,18) parse error Incomplete structured construct at or before this point in expression

tests/service/data/SyntaxTree/Expression/Rarrow 01.fs

@@ -0,0 +1,3 @@
+module Module
+
+-> 1

tests/service/data/SyntaxTree/Expression/Rarrow 01.fs.bsl

@@ -0,0 +1,15 @@
+ImplFile
+  (ParsedImplFileInput
+     ("/root/Expression/Rarrow 01.fs", false, QualifiedNameOfFile Module, [], [],
+      [SynModuleOrNamespace
+         ([Module], false, NamedModule,
+          [Expr
+             (YieldOrReturn
+                ((true, true), Const (Int32 1, (3,3--3,4)), (3,0--3,4)),
+              (3,0--3,4))],
+          PreXmlDoc ((1,0), FSharp.Compiler.Xml.XmlDocCollector), [], None,
+          (1,0--3,4), { LeadingKeyword = Module (1,0--1,6) })], (true, true),
+      { ConditionalDirectives = []
+        CodeComments = [] }, set []))
+
+(3,0)-(3,4) parse error The use of '->' in sequence and computation expressions is limited to the form 'for pat in expr -> expr'. Use the syntax 'for ... in ... do ... yield...' to generate elements in more complex sequence expressions.

tests/service/data/SyntaxTree/Expression/Rarrow 02.fs

@@ -0,0 +1,3 @@
+module Module
+
+->

tests/service/data/SyntaxTree/Expression/Rarrow 02.fs.bsl

@@ -0,0 +1,17 @@
+ImplFile
+  (ParsedImplFileInput
+     ("/root/Expression/Rarrow 02.fs", false, QualifiedNameOfFile Module, [], [],
+      [SynModuleOrNamespace
+         ([Module], false, NamedModule,
+          [Expr
+             (YieldOrReturn
+                ((true, true),
+                 ArbitraryAfterError ("typedSequentialExprBlockR", (3,0--3,2)),
+                 (3,0--3,2)), (3,0--3,2))],
+          PreXmlDoc ((1,0), FSharp.Compiler.Xml.XmlDocCollector), [], None,
+          (1,0--3,2), { LeadingKeyword = Module (1,0--1,6) })], (true, true),
+      { ConditionalDirectives = []
+        CodeComments = [] }, set []))
+
+(4,0)-(4,0) parse error Incomplete structured construct at or before this point in expression
+(3,0)-(4,0) parse error The use of '->' in sequence and computation expressions is limited to the form 'for pat in expr -> expr'. Use the syntax 'for ... in ... do ... yield...' to generate elements in more complex sequence expressions.

tests/service/data/SyntaxTree/Expression/Rarrow 03.fs

@@ -0,0 +1,3 @@
+module Module
+
+-> ->

tests/service/data/SyntaxTree/Expression/Rarrow 03.fs.bsl

@@ -0,0 +1,21 @@
+ImplFile
+  (ParsedImplFileInput
+     ("/root/Expression/Rarrow 03.fs", false, QualifiedNameOfFile Module, [], [],
+      [SynModuleOrNamespace
+         ([Module], false, NamedModule,
+          [Expr
+             (YieldOrReturn
+                ((true, true),
+                 YieldOrReturn
+                   ((true, true),
+                    ArbitraryAfterError
+                      ("typedSequentialExprBlockR", (3,3--3,5)), (3,3--3,5)),
+                 (3,0--3,5)), (3,0--3,5))],
+          PreXmlDoc ((1,0), FSharp.Compiler.Xml.XmlDocCollector), [], None,
+          (1,0--3,5), { LeadingKeyword = Module (1,0--1,6) })], (true, true),
+      { ConditionalDirectives = []
+        CodeComments = [] }, set []))
+
+(4,0)-(4,0) parse error Incomplete structured construct at or before this point in expression
+(3,3)-(4,0) parse error The use of '->' in sequence and computation expressions is limited to the form 'for pat in expr -> expr'. Use the syntax 'for ... in ... do ... yield...' to generate elements in more complex sequence expressions.
+(3,0)-(4,0) parse error The use of '->' in sequence and computation expressions is limited to the form 'for pat in expr -> expr'. Use the syntax 'for ... in ... do ... yield...' to generate elements in more complex sequence expressions.

tests/service/data/SyntaxTree/Expression/Try with - Missing expr 01.fs

@@ -0,0 +1,4 @@
+module Module
+
+try
+with _ -> ()