Terminology correction. End with respect to spans and ranges should

always be exclusive while Last should be inclusive.  The LineRange and
SnapshotLineRange types were incorrectly using End when they meant Last.
Corrected the problem

CodingGuidelines.txt

@@ -1,5 +1,8 @@
 
 F# 
+ - Terminology
+    - Last is inclusive
+    - End is not inclusive
  - Util classes should contain Create methods to create 
  - Revisit: Util classes should have Get for conversions 
  - Should be Of for type conversions in util classes

VimCore/CommandUtil.fs

@@ -1048,7 +1048,7 @@ type internal CommandUtil
 
         // Extend the range to at least 2 lines if possible
         let range = 
-            if range.Count = 1 && range.EndLineNumber = SnapshotUtil.GetLastLineNumber range.Snapshot then
+            if range.Count = 1 && range.LastLineNumber = SnapshotUtil.GetLastLineNumber range.Snapshot then
                 // Can't extend
                 range
             elif range.Count = 1 then

VimCore/CoreInterfaces.fs

@@ -943,7 +943,7 @@ type CharacterSpan
             if lineRange.Count = 1 then
                 span.Length
             else
-                let diff = span.End.Position - lineRange.EndLine.Start.Position
+                let diff = span.End.Position - lineRange.LastLine.Start.Position
                 max 0 diff
         CharacterSpan(span.Start, lineRange.Count, lastLineLength)
 
@@ -1139,7 +1139,7 @@ and [<RequireQualifiedAccess>] [<StructuralEquality>] [<NoComparison>] VisualSel
             // and can be on any column in either
             let line = 
                 if isForward then
-                    snapshotLineRange.EndLine
+                    snapshotLineRange.LastLine
                 else
                     snapshotLineRange.StartLine
 
@@ -1216,7 +1216,7 @@ and [<RequireQualifiedAccess>] [<StructuralEquality>] [<NoComparison>] VisualSel
         | VisualSpan.Character span -> 
             VisualSelection.Character (span, true)
         | VisualSpan.Line lineRange ->
-            let column = SnapshotPointUtil.GetColumn lineRange.EndLine.End
+            let column = SnapshotPointUtil.GetColumn lineRange.LastLine.End
             VisualSelection.Line (lineRange, true, column)
         | VisualSpan.Block blockSpan ->
             VisualSelection.Block (blockSpan, BlockCaretLocation.BottomRight)

VimCore/EditorUtil.fs

@@ -20,23 +20,23 @@ type LineRange
     ) =
 
     member x.StartLineNumber = _startLine
-    member x.EndLineNumber = _startLine + (_count - 1)
+    member x.LastLineNumber = _startLine + (_count - 1)
     member x.Count = _count
     member x.LineNumbers = 
         let startLineNumber = x.StartLineNumber
-        let endLineNumber = x.EndLineNumber
+        let lastLineNumber = x.LastLineNumber
         seq { 
-            for i in startLineNumber .. endLineNumber do yield i 
+            for i in startLineNumber .. lastLineNumber do yield i 
         }
 
     member x.ContainsLineNumber lineNumber = 
-        lineNumber >= _startLine && lineNumber <= x.EndLineNumber
+        lineNumber >= _startLine && lineNumber <= x.LastLineNumber
 
     member x.Intersects (lineRange : LineRange) =
         x.ContainsLineNumber lineRange.StartLineNumber || 
-        x.ContainsLineNumber x.EndLineNumber ||
-        x.EndLineNumber + 1 = lineRange.StartLineNumber ||
-        x.StartLineNumber = lineRange.EndLineNumber + 1
+        x.ContainsLineNumber x.LastLineNumber ||
+        x.LastLineNumber + 1 = lineRange.StartLineNumber ||
+        x.StartLineNumber = lineRange.LastLineNumber + 1
 
     // Equality Functions
     override x.GetHashCode() = _startLine ^^^ _count
@@ -53,17 +53,17 @@ type LineRange
     static member op_Inequality(this,other) = 
         not (System.Collections.Generic.EqualityComparer<LineRange>.Default.Equals(this,other))
 
-    static member CreateFromBounds startLineNumber endLineNumber =
-        let count = (endLineNumber - startLineNumber) + 1
+    static member CreateFromBounds startLineNumber lastLineNumber =
+        let count = (lastLineNumber - startLineNumber) + 1
         LineRange(startLineNumber, count)
 
     static member CreateOverarching (leftLineRange : LineRange) (rightLineRange : LineRange) =
         let startLineNumber = min leftLineRange.StartLineNumber rightLineRange.StartLineNumber
-        let endLineNumber = max leftLineRange.EndLineNumber rightLineRange.EndLineNumber
-        LineRange.CreateFromBounds startLineNumber endLineNumber
+        let lastLineNumber = max leftLineRange.LastLineNumber rightLineRange.LastLineNumber
+        LineRange.CreateFromBounds startLineNumber lastLineNumber
 
     // Overrides
-    override x.ToString() = sprintf "%d - %d" _startLine x.EndLineNumber
+    override x.ToString() = sprintf "%d - %d" _startLine x.LastLineNumber
 
 /// Represents a range of lines in an ITextSnapshot.  Different from a SnapshotSpan
 /// because it declaratively supports lines instead of a position range
@@ -87,19 +87,19 @@ type SnapshotLineRange
 
     /// Number of lines in the SnapshotLineRange
     member x.Count = _count
-    member x.EndLineNumber = _startLine + (_count - 1)
-    member x.EndLine = _snapshot.GetLineFromLineNumber x.EndLineNumber
-    member x.End = x.EndLine.End
-    member x.EndIncludingLineBreak = x.EndLine.EndIncludingLineBreak
+    member x.LastLineNumber = _startLine + (_count - 1)
+    member x.LastLine = _snapshot.GetLineFromLineNumber x.LastLineNumber
+    member x.End = x.LastLine.End
+    member x.EndIncludingLineBreak = x.LastLine.EndIncludingLineBreak
     member x.Extent=
         let startLine = x.StartLine
-        let endLine = x.EndLine
-        SnapshotSpan(startLine.Start, endLine.End)
+        let lastLine = x.LastLine
+        SnapshotSpan(startLine.Start, lastLine.End)
     member x.ExtentIncludingLineBreak = 
         let startLine = x.StartLine
-        let endLine = x.EndLine
-        SnapshotSpan(startLine.Start, endLine.EndIncludingLineBreak)
-    member x.Lines = seq { for i in _startLine .. x.EndLineNumber do yield _snapshot.GetLineFromLineNumber(i) }
+        let lastLine = x.LastLine
+        SnapshotSpan(startLine.Start, lastLine.EndIncludingLineBreak)
+    member x.Lines = seq { for i in _startLine .. x.LastLineNumber do yield _snapshot.GetLineFromLineNumber(i) }
     member x.GetText() = x.Extent.GetText()
     member x.GetTextIncludingLineBreak() = x.ExtentIncludingLineBreak.GetText()
 
@@ -121,7 +121,7 @@ type SnapshotLineRange
         not (System.Collections.Generic.EqualityComparer<SnapshotLineRange>.Default.Equals(this,other))
 
     // Overrides
-    override x.ToString() = sprintf "%d - %d : %s" _startLine x.EndLineNumber (x.Extent.ToString()) 
+    override x.ToString() = sprintf "[%d - %d] : %s" _startLine x.LastLineNumber (x.Extent.ToString()) 
 
 /// Contains operations to help fudge the Editor APIs to be more F# friendly.  Does not
 /// include any Vim specific logic

VimCore/Modes_Command_CommandProcessor.fs

@@ -390,7 +390,7 @@ type internal CommandProcessor
             |> CommandParseUtil.SkipRegister _registerMap
 
         let range = _rangeUtil.RangeOrCurrentLine range
-        _commandOperations.PutLine reg range.EndLine bang
+        _commandOperations.PutLine reg range.LastLine bang
 
     /// Process the search pattern command
     member x.ProcessSearchPattern path (rest : char list) range _ =
@@ -402,7 +402,7 @@ type internal CommandProcessor
         // The search should begin after the last line in the specified range
         let startPoint = 
             let range = _rangeUtil.RangeOrCurrentLine range
-            range.EndLine.End
+            range.LastLine.End
 
         let patternData = { Pattern = pattern; Path = path }
         let result = _searchService.FindNextPattern patternData startPoint _vimBufferData.VimTextBuffer.WordNavigator 1

VimCore/Modes_Command_RangeUtil.fs

@@ -48,7 +48,7 @@ type internal RangeUtil
 
     member x.ApplyCount count (range:SnapshotLineRange) =
         let count = if count <= 1 then 1 else count
-        SnapshotLineRangeUtil.CreateForLineAndMaxCount range.EndLine count
+        SnapshotLineRangeUtil.CreateForLineAndMaxCount range.LastLine count
 
     member x.TryApplyCount count range =
         match count with 
@@ -73,8 +73,8 @@ type internal RangeUtil
             if left.StartLineNumber < right.StartLineNumber then left.StartLine
             else right.StartLine
         let endLine =
-            if left.EndLineNumber > right.EndLineNumber then left.EndLine
-            else right.EndLine
+            if left.LastLineNumber > right.LastLineNumber then left.LastLine
+            else right.LastLine
         SnapshotLineRangeUtil.CreateForLineRange startLine endLine
 
     member x.ParseNumber (input : char list) =
@@ -155,7 +155,7 @@ type internal RangeUtil
                         let number = max 0 (range.StartLineNumber - count)
                         range.Snapshot.GetLineFromLineNumber(number) |> SnapshotLineRangeUtil.CreateForLine 
                     else 
-                        let endLineNumber = max 0 (range.EndLineNumber - count)
+                        let endLineNumber = max 0 (range.LastLineNumber - count)
                         if endLineNumber = range.StartLineNumber then 
                             SnapshotLineRangeUtil.CreateForLine range.StartLine
                         elif endLineNumber < range.StartLineNumber then

VimCore/Modes_SubstituteConfirm_SubstituteConfirmMode.fs

@@ -214,7 +214,7 @@ type internal SubstituteConfirmMode
                     | None -> None
                     | Some regex ->
                         let isReplaceAll = Util.IsFlagSet data.Flags SubstituteFlags.ReplaceAll
-                        let data = { Regex=regex; SubstituteText=data.Substitute; CurrentMatch =span; LastLineNumber=range.EndLineNumber; IsReplaceAll=isReplaceAll}
+                        let data = { Regex=regex; SubstituteText=data.Substitute; CurrentMatch = span; LastLineNumber = range.LastLineNumber; IsReplaceAll=isReplaceAll}
                         Some data
 
         member x.OnLeave () = 

VimCore/Tagger.fs

@@ -373,10 +373,10 @@ type AsyncTagger<'TData, 'TTag when 'TTag :> ITag>
             let getTagsByChunk (lineRange : SnapshotLineRange) =
                 let snapshot = lineRange.Snapshot
                 let mutable i = lineRange.StartLineNumber
-                while i < lineRange.EndLineNumber do
+                while i < lineRange.LastLineNumber do
                     cancellationToken.ThrowIfCancellationRequested()
 
-                    let endLineNumber = min lineRange.EndLineNumber (i + chunkCount)
+                    let endLineNumber = min lineRange.LastLineNumber (i + chunkCount)
                     let chunkLineRange = SnapshotLineRangeUtil.CreateForLineNumberRange snapshot i endLineNumber
                     getTags chunkLineRange
 
@@ -399,7 +399,7 @@ type AsyncTagger<'TData, 'TTag when 'TTag :> ITag>
                     getTagsByChunk lineRange
 
                 // Now do the lines below
-                if visibleLineRange.EndLineNumber < lineRange.EndLineNumber then
+                if visibleLineRange.LastLineNumber < lineRange.LastLineNumber then
                     let lineRange = 
                         let span = SnapshotSpan(visibleLineRange.EndIncludingLineBreak, lineRange.EndIncludingLineBreak)
                         SnapshotLineRangeUtil.CreateForSpan span

VimCoreTest/RangeUtilTest.cs

@@ -42,7 +42,7 @@ private void ParseLineRange(string input, int startLine, int endLine, int contex
             Assert.AreEqual(0, ret.AsSucceeded().Item2.Count());
             var range = ret.AsSucceeded().Item1;
             Assert.AreEqual(startLine, range.StartLineNumber);
-            Assert.AreEqual(endLine, range.EndLineNumber);
+            Assert.AreEqual(endLine, range.LastLineNumber);
         }
 
         private void ParseSingleLine(string input, int line)

VimCoreTest/SnapshotLineRangeUtilTest.cs

@@ -25,7 +25,7 @@ public void CreateForLine()
             Assert.AreEqual("hello", range.Extent.GetText());
             Assert.AreEqual(1, range.Count);
             Assert.AreEqual(0, range.StartLineNumber);
-            Assert.AreEqual(0, range.EndLineNumber);
+            Assert.AreEqual(0, range.LastLineNumber);
         }
 
         [Test]
@@ -36,7 +36,7 @@ public void CreateForLineNumberAndCount1()
             Assert.AreEqual("hello", range.Extent.GetText());
             Assert.AreEqual(1, range.Count);
             Assert.AreEqual(0, range.StartLineNumber);
-            Assert.AreEqual(0, range.EndLineNumber);
+            Assert.AreEqual(0, range.LastLineNumber);
         }
 
         [Test]
@@ -47,7 +47,7 @@ public void CreateForLineNumberAndCount2()
             Assert.AreEqual("hello" + Environment.NewLine + "world", range.Extent.GetText());
             Assert.AreEqual(2, range.Count);
             Assert.AreEqual(0, range.StartLineNumber);
-            Assert.AreEqual(1, range.EndLineNumber);
+            Assert.AreEqual(1, range.LastLineNumber);
         }
 
         [Test]
@@ -67,7 +67,7 @@ public void CreateForLineNumberRange1()
             Assert.AreEqual("hello", range.Extent.GetText());
             Assert.AreEqual(1, range.Count);
             Assert.AreEqual(0, range.StartLineNumber);
-            Assert.AreEqual(0, range.EndLineNumber);
+            Assert.AreEqual(0, range.LastLineNumber);
         }
 
         [Test]
@@ -78,7 +78,7 @@ public void CreateForLineNumberRange2()
             Assert.AreEqual("hello" + Environment.NewLine + "world", range.Extent.GetText());
             Assert.AreEqual(2, range.Count);
             Assert.AreEqual(0, range.StartLineNumber);
-            Assert.AreEqual(1, range.EndLineNumber);
+            Assert.AreEqual(1, range.LastLineNumber);
         }
 
         [Test]
@@ -89,7 +89,7 @@ public void CreateForLineAndMaxCount1()
             var range = SnapshotLineRangeUtil.CreateForLineAndMaxCount(_buffer.GetLine(0), 1);
             Assert.AreEqual(1, range.Count);
             Assert.AreEqual(0, range.StartLineNumber);
-            Assert.AreEqual(0, range.EndLineNumber);
+            Assert.AreEqual(0, range.LastLineNumber);
         }
 
         [Test]
@@ -100,7 +100,7 @@ public void CreateForLineAndMaxCount2()
             var range = SnapshotLineRangeUtil.CreateForLineAndMaxCount(_buffer.GetLine(0), 100);
             Assert.AreEqual(2, range.Count);
             Assert.AreEqual(0, range.StartLineNumber);
-            Assert.AreEqual(1, range.EndLineNumber);
+            Assert.AreEqual(1, range.LastLineNumber);
         }
 
         [Test]
@@ -111,7 +111,7 @@ public void CreateForLineAndMaxCount3()
             var range = SnapshotLineRangeUtil.CreateForLineAndMaxCount(_buffer.GetLine(0), 2);
             Assert.AreEqual(2, range.Count);
             Assert.AreEqual(0, range.StartLineNumber);
-            Assert.AreEqual(1, range.EndLineNumber);
+            Assert.AreEqual(1, range.LastLineNumber);
         }
     }
 }

VimUnitTestUtils/Mock/MockObjectFactory.cs

@@ -559,7 +559,7 @@ public static Mock<ITextViewLineCollection> CreateTextViewLineCollection(
             }
 
             mock.SetupGet(x => x.FirstVisibleLine).Returns(CreateTextViewLine(range.StartLine, factory).Object);
-            mock.SetupGet(x => x.LastVisibleLine).Returns(CreateTextViewLine(range.EndLine, factory).Object);
+            mock.SetupGet(x => x.LastVisibleLine).Returns(CreateTextViewLine(range.LastLine, factory).Object);
             mock.SetupGet(x => x.Count).Returns(range.Count);
             return mock;
         }