[FUSE] Fix code folding

docs/Parsing.md

@@ -0,0 +1,61 @@
+# Introduction
+
+This doc aims to keep a list of decisions that have been made around how razor syntax is parsed into a syntax tree.
+
+## Whitespace handling
+
+Whitespace handling is currently differently parsed depending on the chosen emit strategy (runtime or design time).
+
+When in DesignTime whitespace between a CSharp and HTML node is generally parsed as an HTML node, whereas in Runtime the whitespace is parsed as part of a CSharp node. This ensures that at runtime arbitrary whitespace isn't incorrectly emitted as part of the HTML, but in design time the editor will only identify the actual code portion as being CSharp.
+
+An example of this can be seen here: <https://github.com/dotnet/razor/blob/9f10012f7bbee0c17be26de048aee3e5adbc6c80/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Legacy/CSharpCodeParser.cs#L743>
+
+As part of the transition to use only runtime code generation, we had to make some subtle changes to the parsing of whitespace to ensure that the existing behavior in the editor continues to function as before.
+
+Specifically we changed the parsing of trailing whitespace of razor code block directives (i.e. `@code`, `@function` and `@section`). Previously the whitespace was attached to a meta node that included the closing `}`
+
+Using `^` to indicate whitespace:
+
+```csharp
+@code {
+    // code
+}^^^
+
+```
+
+This would be previously be conceptually parsed as something like:
+
+```text
+CSharpCode
+    RazorDirective
+        CSharpTransition
+        RazorDirectiveBody
+            RazorMetaCode
+                Identifier
+            CSharpCode
+                ...
+            RazorMetaCode
+                Literal: }
+                Literal: ^^^\r\n
+```
+
+Thus when looking at the length of the RazorDirective, it includes the `^^^\r\n`. This causes issues with editor features like code folding. The user only want to fold the directive, not the directive and the following new line. (see <https://github.com/dotnet/razor/issues/10358>)
+
+Instead, we now break the trailing whitespace into its own RazorMetaCode node, which is not a part of the directive itself. Conceptually something like:
+
+```text
+CSharpCode
+    RazorDirective
+        CSharpTransition
+        RazorDirectiveBody
+            RazorMetaCode
+                Identifier
+            CSharpCode
+                ...
+            RazorMetaCode
+                Literal: }
+    RazorMetaCode
+        Literal: ^^^\r\n
+```
+
+In this way we keep the whitespace as belonging to the overall CSharpCode node, but don't make it part of the directive itself, ensuring the editor sees the correct length for the directive.

src/Compiler/Microsoft.AspNetCore.Razor.Language/legacyTest/Legacy/CSharpToMarkupSwitchTest.cs

@@ -4,6 +4,7 @@
 #nullable disable
 
 using System;
+using Microsoft.AspNetCore.Razor.Language.Components;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Razor.Language.Legacy;
@@ -244,4 +245,104 @@ public void SupportsAllKindsOfImplicitMarkupInCodeBlock()
             }
             """);
     }
+
+    [Fact]
+    public void CodeBlocksTrailingWhitespace_01()
+    {
+        ParseDocumentTest("""
+            @code {
+            }
+
+            """, [ComponentCodeDirective.Directive]);
+    }
+
+    [Fact]
+    public void CodeBlocksTrailingWhitespace_02()
+    {
+        ParseDocumentTest("""
+            @code{
+            }                    
+
+            """, [ComponentCodeDirective.Directive]);
+    }
+
+    [Fact]
+    public void CodeBlocksTrailingWhitespace_03()
+    {
+        ParseDocumentTest("""
+            @code{
+            }                    @* comment *@
+
+            """, [ComponentCodeDirective.Directive]);
+    }
+
+    [Fact]
+    public void CodeBlocksTrailingWhitespace_04()
+    {
+        ParseDocumentTest("""
+            @code{
+            }
+            @* comment *@
+
+            """, [ComponentCodeDirective.Directive]);
+    }
+
+    [Fact]
+    public void CodeBlocksTrailingWhitespace_05()
+    {
+        ParseDocumentTest("""
+            @code {
+            }
+
+            @code {
+            }
+
+            """, [ComponentCodeDirective.Directive]);
+    }
+
+    [Fact]
+    public void CodeBlocksTrailingWhitespace_06()
+    {
+        ParseDocumentTest("""
+            @code {
+            }
+
+            <div></div>
+
+            """, [ComponentCodeDirective.Directive]);
+    }
+
+    [Fact]
+    public void CodeBlocksTrailingWhitespace_07()
+    {
+        ParseDocumentTest("""
+            @code {
+
+            }
+            <div></div>
+
+            """, [ComponentCodeDirective.Directive]);
+    }
+
+    [Fact]
+    public void CodeBlocksTrailingWhitespace_08()
+    {
+        ParseDocumentTest("""
+            @code {
+
+            }      <div></div>
+
+            """, [ComponentCodeDirective.Directive]);
+    }
+
+    [Fact]
+    public void CodeBlocksTrailingWhitespace_09()
+    {
+        ParseDocumentTest("""
+            @code {
+
+            }<div></div>
+
+            """, [ComponentCodeDirective.Directive]);
+    }
 }

src/Compiler/Microsoft.AspNetCore.Razor.Language/legacyTest/TestFiles/ParserTests/CSharpToMarkupSwitchTest/CodeBlocksTrailingWhitespace_01.cspans.txt

@@ -0,0 +1,8 @@
+Markup span at (0:0,0 [0] ) (Accepts:Any) - Parent: Markup block at (0:0,0 [12] )
+Transition span at (0:0,0 [1] ) (Accepts:None) - Parent: Directive block at (0:0,0 [10] )
+MetaCode span at (1:0,1 [4] ) (Accepts:None) - Parent: Directive block at (0:0,0 [10] )
+None span at (5:0,5 [1] ) (Accepts:AllWhitespace) - Parent: Directive block at (0:0,0 [10] )
+MetaCode span at (6:0,6 [1] ) (Accepts:None) - Parent: Directive block at (0:0,0 [10] )
+Code span at (7:0,7 [2] ) (Accepts:Any) - Parent: Directive block at (0:0,0 [10] )
+MetaCode span at (9:1,0 [1] ) (Accepts:None) - Parent: Directive block at (0:0,0 [10] )
+MetaCode span at (10:1,1 [2] ) (Accepts:Any) - Parent: Statement block at (0:0,0 [12] )

src/Compiler/Microsoft.AspNetCore.Razor.Language/legacyTest/TestFiles/ParserTests/CSharpToMarkupSwitchTest/CodeBlocksTrailingWhitespace_01.stree.txt

@@ -0,0 +1,24 @@
+RazorDocument - [0..12)::12 - [@code {LF}LF]
+    MarkupBlock - [0..12)::12
+        MarkupTextLiteral - [0..0)::0 - [] - Gen<Markup> - SpanEditHandler;Accepts:Any
+            Marker;[];
+        CSharpCodeBlock - [0..12)::12
+            RazorDirective - [0..10)::10 - Directive:{code;CodeBlock;Unrestricted}
+                CSharpTransition - [0..1)::1 - Gen<None> - SpanEditHandler;Accepts:None
+                    Transition;[@];
+                RazorDirectiveBody - [1..10)::9
+                    RazorMetaCode - [1..5)::4 - Gen<None> - SpanEditHandler;Accepts:None
+                        Identifier;[code];
+                    CSharpCodeBlock - [5..10)::5
+                        UnclassifiedTextLiteral - [5..6)::1 - [ ] - Gen<None> - SpanEditHandler;Accepts:AllWhitespace
+                            Whitespace;[ ];
+                        RazorMetaCode - [6..7)::1 - Gen<None> - AutoCompleteEditHandler;Accepts:None,AutoComplete:[<null>];AtEnd
+                            LeftBrace;[{];
+                        CSharpCodeBlock - [7..9)::2
+                            CSharpStatementLiteral - [7..9)::2 - [LF] - Gen<Stmt> - CodeBlockEditHandler;Accepts:Any;CodeBlock
+                                NewLine;[LF];
+                        RazorMetaCode - [9..10)::1 - Gen<None> - SpanEditHandler;Accepts:None
+                            RightBrace;[}];
+            RazorMetaCode - [10..12)::2 - Gen<None> - SpanEditHandler;Accepts:Any
+                NewLine;[LF];
+    EndOfFile;[];

src/Compiler/Microsoft.AspNetCore.Razor.Language/legacyTest/TestFiles/ParserTests/CSharpToMarkupSwitchTest/CodeBlocksTrailingWhitespace_02.cspans.txt

@@ -0,0 +1,7 @@
+Markup span at (0:0,0 [0] ) (Accepts:Any) - Parent: Markup block at (0:0,0 [31] )
+Transition span at (0:0,0 [1] ) (Accepts:None) - Parent: Directive block at (0:0,0 [9] )
+MetaCode span at (1:0,1 [4] ) (Accepts:None) - Parent: Directive block at (0:0,0 [9] )
+MetaCode span at (5:0,5 [1] ) (Accepts:None) - Parent: Directive block at (0:0,0 [9] )
+Code span at (6:0,6 [2] ) (Accepts:Any) - Parent: Directive block at (0:0,0 [9] )
+MetaCode span at (8:1,0 [1] ) (Accepts:None) - Parent: Directive block at (0:0,0 [9] )
+MetaCode span at (9:1,1 [22] ) (Accepts:Any) - Parent: Statement block at (0:0,0 [31] )

src/Compiler/Microsoft.AspNetCore.Razor.Language/legacyTest/TestFiles/ParserTests/CSharpToMarkupSwitchTest/CodeBlocksTrailingWhitespace_02.stree.txt

@@ -0,0 +1,23 @@
+RazorDocument - [0..31)::31 - [@code{LF}                    LF]
+    MarkupBlock - [0..31)::31
+        MarkupTextLiteral - [0..0)::0 - [] - Gen<Markup> - SpanEditHandler;Accepts:Any
+            Marker;[];
+        CSharpCodeBlock - [0..31)::31
+            RazorDirective - [0..9)::9 - Directive:{code;CodeBlock;Unrestricted}
+                CSharpTransition - [0..1)::1 - Gen<None> - SpanEditHandler;Accepts:None
+                    Transition;[@];
+                RazorDirectiveBody - [1..9)::8
+                    RazorMetaCode - [1..5)::4 - Gen<None> - SpanEditHandler;Accepts:None
+                        Identifier;[code];
+                    CSharpCodeBlock - [5..9)::4
+                        RazorMetaCode - [5..6)::1 - Gen<None> - AutoCompleteEditHandler;Accepts:None,AutoComplete:[<null>];AtEnd
+                            LeftBrace;[{];
+                        CSharpCodeBlock - [6..8)::2
+                            CSharpStatementLiteral - [6..8)::2 - [LF] - Gen<Stmt> - CodeBlockEditHandler;Accepts:Any;CodeBlock
+                                NewLine;[LF];
+                        RazorMetaCode - [8..9)::1 - Gen<None> - SpanEditHandler;Accepts:None
+                            RightBrace;[}];
+            RazorMetaCode - [9..31)::22 - Gen<None> - SpanEditHandler;Accepts:Any
+                Whitespace;[                    ];
+                NewLine;[LF];
+    EndOfFile;[];

src/Compiler/Microsoft.AspNetCore.Razor.Language/legacyTest/TestFiles/ParserTests/CSharpToMarkupSwitchTest/CodeBlocksTrailingWhitespace_03.cspans.txt

@@ -0,0 +1,13 @@
+Markup span at (0:0,0 [0] ) (Accepts:Any) - Parent: Markup block at (0:0,0 [44] )
+Transition span at (0:0,0 [1] ) (Accepts:None) - Parent: Directive block at (0:0,0 [9] )
+MetaCode span at (1:0,1 [4] ) (Accepts:None) - Parent: Directive block at (0:0,0 [9] )
+MetaCode span at (5:0,5 [1] ) (Accepts:None) - Parent: Directive block at (0:0,0 [9] )
+Code span at (6:0,6 [2] ) (Accepts:Any) - Parent: Directive block at (0:0,0 [9] )
+MetaCode span at (8:1,0 [1] ) (Accepts:None) - Parent: Directive block at (0:0,0 [9] )
+Markup span at (9:1,1 [20] ) (Accepts:Any) - Parent: Markup block at (0:0,0 [44] )
+Transition span at (29:1,21 [1] ) (Accepts:None) - Parent: Comment block at (29:1,21 [13] )
+MetaCode span at (30:1,22 [1] ) (Accepts:None) - Parent: Comment block at (29:1,21 [13] )
+Comment span at (31:1,23 [9] ) (Accepts:Any) - Parent: Comment block at (29:1,21 [13] )
+MetaCode span at (40:1,32 [1] ) (Accepts:None) - Parent: Comment block at (29:1,21 [13] )
+Transition span at (41:1,33 [1] ) (Accepts:None) - Parent: Comment block at (29:1,21 [13] )
+Markup span at (42:1,34 [2] ) (Accepts:Any) - Parent: Markup block at (0:0,0 [44] )

src/Compiler/Microsoft.AspNetCore.Razor.Language/legacyTest/TestFiles/ParserTests/CSharpToMarkupSwitchTest/CodeBlocksTrailingWhitespace_03.stree.txt

@@ -0,0 +1,30 @@
+RazorDocument - [0..44)::44 - [@code{LF}                    @* comment *@LF]
+    MarkupBlock - [0..44)::44
+        MarkupTextLiteral - [0..0)::0 - [] - Gen<Markup> - SpanEditHandler;Accepts:Any
+            Marker;[];
+        CSharpCodeBlock - [0..9)::9
+            RazorDirective - [0..9)::9 - Directive:{code;CodeBlock;Unrestricted}
+                CSharpTransition - [0..1)::1 - Gen<None> - SpanEditHandler;Accepts:None
+                    Transition;[@];
+                RazorDirectiveBody - [1..9)::8
+                    RazorMetaCode - [1..5)::4 - Gen<None> - SpanEditHandler;Accepts:None
+                        Identifier;[code];
+                    CSharpCodeBlock - [5..9)::4
+                        RazorMetaCode - [5..6)::1 - Gen<None> - AutoCompleteEditHandler;Accepts:None,AutoComplete:[<null>];AtEnd
+                            LeftBrace;[{];
+                        CSharpCodeBlock - [6..8)::2
+                            CSharpStatementLiteral - [6..8)::2 - [LF] - Gen<Stmt> - CodeBlockEditHandler;Accepts:Any;CodeBlock
+                                NewLine;[LF];
+                        RazorMetaCode - [8..9)::1 - Gen<None> - SpanEditHandler;Accepts:None
+                            RightBrace;[}];
+        MarkupTextLiteral - [9..29)::20 - [                    ] - Gen<Markup> - SpanEditHandler;Accepts:Any
+            Whitespace;[                    ];
+        RazorComment - [29..42)::13
+            RazorCommentTransition;[@];
+            RazorCommentStar;[*];
+            RazorCommentLiteral;[ comment ];
+            RazorCommentStar;[*];
+            RazorCommentTransition;[@];
+        MarkupTextLiteral - [42..44)::2 - [LF] - Gen<Markup> - SpanEditHandler;Accepts:Any
+            NewLine;[LF];
+    EndOfFile;[];

src/Compiler/Microsoft.AspNetCore.Razor.Language/legacyTest/TestFiles/ParserTests/CSharpToMarkupSwitchTest/CodeBlocksTrailingWhitespace_04.cspans.txt

@@ -0,0 +1,13 @@
+Markup span at (0:0,0 [0] ) (Accepts:Any) - Parent: Markup block at (0:0,0 [26] )
+Transition span at (0:0,0 [1] ) (Accepts:None) - Parent: Directive block at (0:0,0 [9] )
+MetaCode span at (1:0,1 [4] ) (Accepts:None) - Parent: Directive block at (0:0,0 [9] )
+MetaCode span at (5:0,5 [1] ) (Accepts:None) - Parent: Directive block at (0:0,0 [9] )
+Code span at (6:0,6 [2] ) (Accepts:Any) - Parent: Directive block at (0:0,0 [9] )
+MetaCode span at (8:1,0 [1] ) (Accepts:None) - Parent: Directive block at (0:0,0 [9] )
+MetaCode span at (9:1,1 [2] ) (Accepts:Any) - Parent: Statement block at (0:0,0 [11] )
+Transition span at (11:2,0 [1] ) (Accepts:None) - Parent: Comment block at (11:2,0 [13] )
+MetaCode span at (12:2,1 [1] ) (Accepts:None) - Parent: Comment block at (11:2,0 [13] )
+Comment span at (13:2,2 [9] ) (Accepts:Any) - Parent: Comment block at (11:2,0 [13] )
+MetaCode span at (22:2,11 [1] ) (Accepts:None) - Parent: Comment block at (11:2,0 [13] )
+Transition span at (23:2,12 [1] ) (Accepts:None) - Parent: Comment block at (11:2,0 [13] )
+Markup span at (24:2,13 [2] ) (Accepts:Any) - Parent: Markup block at (0:0,0 [26] )

src/Compiler/Microsoft.AspNetCore.Razor.Language/legacyTest/TestFiles/ParserTests/CSharpToMarkupSwitchTest/CodeBlocksTrailingWhitespace_04.stree.txt

@@ -0,0 +1,30 @@
+RazorDocument - [0..26)::26 - [@code{LF}LF@* comment *@LF]
+    MarkupBlock - [0..26)::26
+        MarkupTextLiteral - [0..0)::0 - [] - Gen<Markup> - SpanEditHandler;Accepts:Any
+            Marker;[];
+        CSharpCodeBlock - [0..11)::11
+            RazorDirective - [0..9)::9 - Directive:{code;CodeBlock;Unrestricted}
+                CSharpTransition - [0..1)::1 - Gen<None> - SpanEditHandler;Accepts:None
+                    Transition;[@];
+                RazorDirectiveBody - [1..9)::8
+                    RazorMetaCode - [1..5)::4 - Gen<None> - SpanEditHandler;Accepts:None
+                        Identifier;[code];
+                    CSharpCodeBlock - [5..9)::4
+                        RazorMetaCode - [5..6)::1 - Gen<None> - AutoCompleteEditHandler;Accepts:None,AutoComplete:[<null>];AtEnd
+                            LeftBrace;[{];
+                        CSharpCodeBlock - [6..8)::2
+                            CSharpStatementLiteral - [6..8)::2 - [LF] - Gen<Stmt> - CodeBlockEditHandler;Accepts:Any;CodeBlock
+                                NewLine;[LF];
+                        RazorMetaCode - [8..9)::1 - Gen<None> - SpanEditHandler;Accepts:None
+                            RightBrace;[}];
+            RazorMetaCode - [9..11)::2 - Gen<None> - SpanEditHandler;Accepts:Any
+                NewLine;[LF];
+        RazorComment - [11..24)::13
+            RazorCommentTransition;[@];
+            RazorCommentStar;[*];
+            RazorCommentLiteral;[ comment ];
+            RazorCommentStar;[*];
+            RazorCommentTransition;[@];
+        MarkupEphemeralTextLiteral - [24..26)::2 - [LF] - Gen<None> - SpanEditHandler;Accepts:Any
+            NewLine;[LF];
+    EndOfFile;[];

src/Compiler/Microsoft.AspNetCore.Razor.Language/legacyTest/TestFiles/ParserTests/CSharpToMarkupSwitchTest/CodeBlocksTrailingWhitespace_05.cspans.txt

@@ -0,0 +1,16 @@
+Markup span at (0:0,0 [0] ) (Accepts:Any) - Parent: Markup block at (0:0,0 [26] )
+Transition span at (0:0,0 [1] ) (Accepts:None) - Parent: Directive block at (0:0,0 [10] )
+MetaCode span at (1:0,1 [4] ) (Accepts:None) - Parent: Directive block at (0:0,0 [10] )
+None span at (5:0,5 [1] ) (Accepts:AllWhitespace) - Parent: Directive block at (0:0,0 [10] )
+MetaCode span at (6:0,6 [1] ) (Accepts:None) - Parent: Directive block at (0:0,0 [10] )
+Code span at (7:0,7 [2] ) (Accepts:Any) - Parent: Directive block at (0:0,0 [10] )
+MetaCode span at (9:1,0 [1] ) (Accepts:None) - Parent: Directive block at (0:0,0 [10] )
+MetaCode span at (10:1,1 [2] ) (Accepts:Any) - Parent: Statement block at (0:0,0 [12] )
+Markup span at (12:2,0 [2] ) (Accepts:Any) - Parent: Markup block at (0:0,0 [26] )
+Transition span at (14:3,0 [1] ) (Accepts:None) - Parent: Directive block at (14:3,0 [10] )
+MetaCode span at (15:3,1 [4] ) (Accepts:None) - Parent: Directive block at (14:3,0 [10] )
+None span at (19:3,5 [1] ) (Accepts:AllWhitespace) - Parent: Directive block at (14:3,0 [10] )
+MetaCode span at (20:3,6 [1] ) (Accepts:None) - Parent: Directive block at (14:3,0 [10] )
+Code span at (21:3,7 [2] ) (Accepts:Any) - Parent: Directive block at (14:3,0 [10] )
+MetaCode span at (23:4,0 [1] ) (Accepts:None) - Parent: Directive block at (14:3,0 [10] )
+MetaCode span at (24:4,1 [2] ) (Accepts:Any) - Parent: Statement block at (14:3,0 [12] )

src/Compiler/Microsoft.AspNetCore.Razor.Language/legacyTest/TestFiles/ParserTests/CSharpToMarkupSwitchTest/CodeBlocksTrailingWhitespace_05.stree.txt

@@ -0,0 +1,45 @@
+RazorDocument - [0..26)::26 - [@code {LF}LFLF@code {LF}LF]
+    MarkupBlock - [0..26)::26
+        MarkupTextLiteral - [0..0)::0 - [] - Gen<Markup> - SpanEditHandler;Accepts:Any
+            Marker;[];
+        CSharpCodeBlock - [0..12)::12
+            RazorDirective - [0..10)::10 - Directive:{code;CodeBlock;Unrestricted}
+                CSharpTransition - [0..1)::1 - Gen<None> - SpanEditHandler;Accepts:None
+                    Transition;[@];
+                RazorDirectiveBody - [1..10)::9
+                    RazorMetaCode - [1..5)::4 - Gen<None> - SpanEditHandler;Accepts:None
+                        Identifier;[code];
+                    CSharpCodeBlock - [5..10)::5
+                        UnclassifiedTextLiteral - [5..6)::1 - [ ] - Gen<None> - SpanEditHandler;Accepts:AllWhitespace
+                            Whitespace;[ ];
+                        RazorMetaCode - [6..7)::1 - Gen<None> - AutoCompleteEditHandler;Accepts:None,AutoComplete:[<null>];AtEnd
+                            LeftBrace;[{];
+                        CSharpCodeBlock - [7..9)::2
+                            CSharpStatementLiteral - [7..9)::2 - [LF] - Gen<Stmt> - CodeBlockEditHandler;Accepts:Any;CodeBlock
+                                NewLine;[LF];
+                        RazorMetaCode - [9..10)::1 - Gen<None> - SpanEditHandler;Accepts:None
+                            RightBrace;[}];
+            RazorMetaCode - [10..12)::2 - Gen<None> - SpanEditHandler;Accepts:Any
+                NewLine;[LF];
+        MarkupTextLiteral - [12..14)::2 - [LF] - Gen<Markup> - SpanEditHandler;Accepts:Any
+            NewLine;[LF];
+        CSharpCodeBlock - [14..26)::12
+            RazorDirective - [14..24)::10 - Directive:{code;CodeBlock;Unrestricted}
+                CSharpTransition - [14..15)::1 - Gen<None> - SpanEditHandler;Accepts:None
+                    Transition;[@];
+                RazorDirectiveBody - [15..24)::9
+                    RazorMetaCode - [15..19)::4 - Gen<None> - SpanEditHandler;Accepts:None
+                        Identifier;[code];
+                    CSharpCodeBlock - [19..24)::5
+                        UnclassifiedTextLiteral - [19..20)::1 - [ ] - Gen<None> - SpanEditHandler;Accepts:AllWhitespace
+                            Whitespace;[ ];
+                        RazorMetaCode - [20..21)::1 - Gen<None> - AutoCompleteEditHandler;Accepts:None,AutoComplete:[<null>];AtEnd
+                            LeftBrace;[{];
+                        CSharpCodeBlock - [21..23)::2
+                            CSharpStatementLiteral - [21..23)::2 - [LF] - Gen<Stmt> - CodeBlockEditHandler;Accepts:Any;CodeBlock
+                                NewLine;[LF];
+                        RazorMetaCode - [23..24)::1 - Gen<None> - SpanEditHandler;Accepts:None
+                            RightBrace;[}];
+            RazorMetaCode - [24..26)::2 - Gen<None> - SpanEditHandler;Accepts:Any
+                NewLine;[LF];
+    EndOfFile;[];