[vi-mode] Supports the text-object command diw (#2059)

PSReadLine/Cmdlets.cs

@@ -142,7 +142,7 @@ public class PSConsoleReadLineOptions
         public const int DefaultCompletionQueryItems = 100;
 
         // Default includes all characters PowerShell treats like a dash - em dash, en dash, horizontal bar
-        public const string DefaultWordDelimiters = @";:,.[]{}()/\|^&*-=+'""" + "\u2013\u2014\u2015";
+        public const string DefaultWordDelimiters = @";:,.[]{}()/\|!?^&*-=+'""" + "\u2013\u2014\u2015";
 
         /// <summary>
         /// When ringing the bell, what should be done?

PSReadLine/KeyBindings.vi.cs

@@ -45,6 +45,8 @@ internal static ConsoleColor AlternateBackground(ConsoleColor bg)
         private static Dictionary<PSKeyInfo, KeyHandler> _viChordYTable;
         private static Dictionary<PSKeyInfo, KeyHandler> _viChordDGTable;
 
+        private static Dictionary<PSKeyInfo, KeyHandler> _viChordTextObjectsTable;
+
         private static Dictionary<PSKeyInfo, Dictionary<PSKeyInfo, KeyHandler>> _viCmdChordTable;
         private static Dictionary<PSKeyInfo, Dictionary<PSKeyInfo, KeyHandler>> _viInsChordTable;
 
@@ -238,6 +240,7 @@ private void SetDefaultViBindings()
                 { Keys.ucG,             MakeKeyHandler( DeleteEndOfBuffer,            "DeleteEndOfBuffer") },
                 { Keys.ucE,             MakeKeyHandler( ViDeleteEndOfGlob,            "ViDeleteEndOfGlob") },
                 { Keys.H,               MakeKeyHandler( BackwardDeleteChar,           "BackwardDeleteChar") },
+                { Keys.I,               MakeKeyHandler( ViChordDeleteTextObject,      "ChordViTextObject") },               
                 { Keys.J,               MakeKeyHandler( DeleteNextLines,              "DeleteNextLines") },
                 { Keys.K,               MakeKeyHandler( DeletePreviousLines,          "DeletePreviousLines") },
                 { Keys.L,               MakeKeyHandler( DeleteChar,                   "DeleteChar") },
@@ -296,6 +299,11 @@ private void SetDefaultViBindings()
                 { Keys.Percent,         MakeKeyHandler( ViYankPercent,         "ViYankPercent") },
             };
 
+            _viChordTextObjectsTable = new Dictionary<PSKeyInfo, KeyHandler>
+            {
+                { Keys.W,               MakeKeyHandler(ViHandleTextObject,     "WordTextObject")},
+            };
+
             _viChordDGTable = new Dictionary<PSKeyInfo, KeyHandler>
             {
                 { Keys.G,               MakeKeyHandler( DeleteRelativeLines,   "DeleteRelativeLines") },

PSReadLine/Position.cs

@@ -102,23 +102,14 @@ private static int GetFirstNonBlankOfLogicalLinePos(int current)
             var beginningOfLine = GetBeginningOfLinePos(current);
 
             var newCurrent = beginningOfLine;
+            var buffer = _singleton._buffer;
 
-            while (newCurrent < _singleton._buffer.Length && IsVisibleBlank(newCurrent))
+            while (newCurrent < buffer.Length && buffer.IsVisibleBlank(newCurrent))
             {
                 newCurrent++;
             }
 
             return newCurrent;
         }
-
-        private static bool IsVisibleBlank(int newCurrent)
-        {
-            var c = _singleton._buffer[newCurrent];
-
-            // [:blank:] of vim's pattern matching behavior
-            // defines blanks as SPACE and TAB characters.
-
-            return c == ' ' || c == '\t';
-        }
     }
 }

PSReadLine/Prediction.Views.cs

@@ -1513,12 +1513,12 @@ internal int FindForwardSuggestionWordPoint(int currentIndex, string wordDelimit
                 }
 
                 int i = currentIndex;
-                if (!_singleton.InWord(_suggestionText[i], wordDelimiters))
+                if (!Character.IsInWord(_suggestionText[i], wordDelimiters))
                 {
                     // Scan to end of current non-word region
                     while (++i < _suggestionText.Length)
                     {
-                        if (_singleton.InWord(_suggestionText[i], wordDelimiters))
+                        if (Character.IsInWord(_suggestionText[i], wordDelimiters))
                         {
                             break;
                         }
@@ -1529,7 +1529,7 @@ internal int FindForwardSuggestionWordPoint(int currentIndex, string wordDelimit
                 {
                     while (++i < _suggestionText.Length)
                     {
-                        if (!_singleton.InWord(_suggestionText[i], wordDelimiters))
+                        if (!Character.IsInWord(_suggestionText[i], wordDelimiters))
                         {
                             if (_suggestionText[i] == ' ')
                             {

PSReadLine/StringBuilderCharacterExtensions.cs

@@ -0,0 +1,78 @@
+using System.Text;
+
+namespace Microsoft.PowerShell
+{
+    internal static class StringBuilderCharacterExtensions
+    {
+        /// <summary>
+        /// Returns true if the character at the specified position is a visible whitespace character.
+        /// A blank character is defined as a SPACE or a TAB.
+        /// </summary>
+        /// <param name="buffer"></param>
+        /// <param name="i"></param>
+        /// <returns></returns>
+        public static bool IsVisibleBlank(this StringBuilder buffer, int i)
+        {
+            var c = buffer[i];
+
+            // [:blank:] of vim's pattern matching behavior
+            // defines blanks as SPACE and TAB characters.
+
+            return c == ' ' || c == '\t';
+        }
+
+        /// <summary>
+        /// Returns true if the character at the specified position is
+        /// not present in a list of word-delimiter characters.
+        /// </summary>
+        /// <param name="buffer"></param>
+        /// <param name="i"></param>
+        /// <param name="wordDelimiters"></param>
+        /// <returns></returns>
+        public static bool InWord(this StringBuilder buffer, int i, string wordDelimiters)
+        {
+            return Character.IsInWord(buffer[i], wordDelimiters);
+        }
+
+        /// <summary>
+        /// Returns true if the character at the specified position is
+        /// at the end of the buffer
+        /// </summary>
+        /// <param name="buffer"></param>
+        /// <param name="i"></param>
+        /// <returns></returns>
+        public static bool IsAtEndOfBuffer(this StringBuilder buffer, int i)
+        {
+            return i >= (buffer.Length - 1);
+        }
+
+        /// <summary>
+        /// Returns true if the character at the specified position is
+        /// a unicode whitespace character.
+        /// </summary>
+        /// <param name="buffer"></param>
+        /// <param name="i"></param>
+        /// <returns></returns>
+        public static bool IsWhiteSpace(this StringBuilder buffer, int i)
+        {
+            // Treat just beyond the end of buffer as whitespace because
+            // it looks like whitespace to the user even though they haven't
+            // entered a character yet.
+            return i >= buffer.Length || char.IsWhiteSpace(buffer[i]);
+        }
+    }
+
+    public static class Character
+    {
+        /// <summary>
+        /// Returns true if the character not present in a list of word-delimiter characters.
+        /// </summary>
+        /// <param name="c"></param>
+        /// <param name="wordDelimiters"></param>
+        /// <returns></returns>
+        public static bool IsInWord(char c, string wordDelimiters)
+        {
+            return !char.IsWhiteSpace(c) && wordDelimiters.IndexOf(c) < 0;
+        }
+    }
+}

PSReadLine/StringBuilderExtensions.cs → PSReadLine/StringBuilderLinewiseExtensions.cs

@@ -72,6 +72,26 @@ internal static Range GetRange(this StringBuilder buffer, int lineIndex, int lin
                 endPosition - startPosition + 1
                 );
         }
+
+        /// <summary>
+        /// Returns true if the specified position is on an empty logical line.
+        /// </summary>
+        /// <param name="buffer"></param>
+        /// <param name="cursor"></param>
+        /// <returns></returns>
+        public static bool IsLogigalLineEmpty(this StringBuilder buffer, int cursor)
+        {
+            // the cursor is on a logical line considered empty if...
+            return 
+                // the entire buffer is empty (by definition),
+                buffer.Length == 0 ||
+                // or the cursor sits at the start of the empty last line,
+                // meaning that it is past the end of the buffer and the
+                // last character in the buffer is a newline character,
+                (cursor == buffer.Length && buffer[cursor - 1] == '\n') ||
+                // or if the cursor is on a newline character.
+                (cursor > 0 && buffer[cursor] == '\n');
+        }
     }
 
     internal static class StringBuilderPredictionExtensions

PSReadLine/StringBuilderTextObjectExtensions.cs

@@ -0,0 +1,113 @@
+using System;
+using System.Text;
+
+namespace Microsoft.PowerShell
+{
+    internal static class StringBuilderTextObjectExtensions
+    {
+        private const string WhiteSpace = " \n\t";
+
+        /// <summary>
+        /// Returns the position of the beginning of the current word as delimited by white space and delimiters
+        /// This method differs from <see cref="ViFindPreviousWordPoint(string)"/>:
+        /// - When the cursor location is on the first character of a word, <see cref="ViFindPreviousWordPoint(string)"/>
+        ///   returns the position of the previous word, whereas this method returns the cursor location.
+        /// - When the cursor location is in a word, both methods return the same result.
+        /// This method supports VI "iw" text object.
+        /// </summary>
+        public static int ViFindBeginningOfWordObjectBoundary(this StringBuilder buffer, int position, string wordDelimiters)
+        {
+            // Cursor may be past the end of the buffer when calling this method
+            // this may happen if the cursor is at the beginning of a new line.
+            var i = Math.Min(position, buffer.Length - 1);
+
+            // If starting on a word consider a text object as a sequence of characters excluding the delimiters,
+            // otherwise, consider a word as a sequence of delimiters.
+            var delimiters = wordDelimiters;
+            var isInWord = buffer.InWord(i, wordDelimiters);
+
+            if (isInWord)
+            {
+                // For the purpose of this method, whitespace character is considered a delimiter.
+                delimiters += WhiteSpace;
+            }
+            else
+            {
+                char c = buffer[i];
+                if ((wordDelimiters + '\n').IndexOf(c) == -1 && char.IsWhiteSpace(c))
+                {
+                    // Current position points to a whitespace that is not a newline.
+                    delimiters = WhiteSpace;
+                }
+                else
+                {
+                    delimiters += '\n';
+                }
+            }
+
+            var isTextObjectChar = isInWord
+                ? (Func<char, bool>)(c => delimiters.IndexOf(c) == -1)
+                : c => delimiters.IndexOf(c) != -1;
+
+            var beginning = i;
+            while (i >= 0 && isTextObjectChar(buffer[i]))
+            {
+                beginning = i--;
+            }
+
+            return beginning;
+        }
+
+        /// <summary>
+        /// Finds the position of the beginning of the next word object starting from the specified position.
+        /// If positioned on the last word in the buffer, returns buffer length + 1.
+        /// This method supports VI "iw" text-object.
+        /// iw: "inner word", select words. White space between words is counted too.
+        /// </summary>
+        public static int ViFindBeginningOfNextWordObjectBoundary(this StringBuilder buffer, int position, string wordDelimiters)
+        {
+            // Cursor may be past the end of the buffer when calling this method
+            // this may happen if the cursor is at the beginning of a new line.
+            var i = Math.Min(position, buffer.Length - 1);
+
+            // Always skip the first newline character.
+            if (buffer[i] == '\n' && i < buffer.Length - 1)
+            {
+                ++i;
+            }
+
+            // If starting on a word consider a text object as a sequence of characters excluding the delimiters,
+            // otherwise, consider a word as a sequence of delimiters.
+            var delimiters = wordDelimiters;
+            var isInWord = buffer.InWord(i, wordDelimiters);
+
+            if (isInWord)
+            {
+                delimiters += WhiteSpace;
+            }
+            else if (char.IsWhiteSpace(buffer[i]))
+            {
+                delimiters = " \t";
+            }
+
+            var isTextObjectChar = isInWord
+                ? (Func<char, bool>)(c => delimiters.IndexOf(c) == -1)
+                : c => delimiters.IndexOf(c) != -1;
+
+            // Try to skip a second newline characters to replicate vim behaviour.
+            if (buffer[i] == '\n' && i < buffer.Length - 1)
+            {
+                ++i;
+            }
+
+            // Skip to next non-word characters.
+            while (i < buffer.Length && isTextObjectChar(buffer[i]))
+            {
+                ++i;
+            }
+
+            // Make sure end includes the starting position.
+            return Math.Max(i, position);
+        }
+    }
+}