Camel Humps for Navigation, Selection and Deletion

PSReadLine/Humps.cs

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+/********************************************************************++
+Copyright (c) Darkstar Developments GmbH 2023. All rights reserved.
+--********************************************************************/
+
+using System.Collections.Generic;
+using System.Management.Automation.Language;
+
+namespace Microsoft.PowerShell
+{
+    public partial class PSConsoleReadLine
+    {
+        private enum FindHumpMode
+        {
+            CurrentOrNext,
+            Next,
+            Previous,
+        }
+
+        /// <summary>
+        /// Find the end of the current/next camel hump.
+        /// </summary>
+        public int FindForwardHumpPoint(string wordDelimiters)
+        {
+            int i = _current;
+            if (i == _buffer.Length)
+                return i;
+
+            if (!InWord(i, wordDelimiters))
+            {
+                // Scan to end of current non-word region
+                while (i < _buffer.Length)
+                {
+                    if (InWord(i, wordDelimiters))
+                        break;
+
+                    i += 1;
+                }
+            }
+            else
+            {
+                if (AtStartOfHump(i, wordDelimiters))
+                    i += 1;
+
+                // scan to the end of this hump
+                while (i < _buffer.Length)
+                {
+                    if (!InHump(i, wordDelimiters))
+                        break;
+
+                    i += 1;
+                }
+            }
+
+            return i;
+        }
+
+
+        /// <summary>
+        /// Find the beginning of this camel hump.
+        /// </summary>
+        public int FindBackwardHumpPoint(string wordDelimiters)
+        {
+            int i = _current - 1;
+            if (i < 0)
+                return 0;
+
+            if (!InWord(i, wordDelimiters))
+            {
+                // scan backwards until we are at the end of the previous word.
+                while (i > 0)
+                {
+                    if (InWord(i, wordDelimiters))
+                    {
+                        // set back one step because we want to be behind the last letter of the word / hump
+                        i += 1;
+                        break;
+                    }
+
+                    i -= 1;
+                }
+            }
+            else
+            {
+                // scan backwards until we are at the end of the previous word.
+                while (i > 0)
+                {
+                    if (!InHump(i, wordDelimiters))
+                        break;
+
+                    i -= 1;
+                }
+            }
+
+            return i;
+        }
+
+        private bool AtStartOfHump(int index, string wordDelimiters)
+        {
+            char c = _buffer[index];
+            return AtStartOfHump(c, wordDelimiters);
+        }
+
+        private bool AtStartOfHump(char c, string wordDelimiters)
+        {
+            return !char.IsWhiteSpace(c) && wordDelimiters.IndexOf(c) < 0 && char.IsUpper(c);
+        }
+
+        private bool InHump(int index, string wordDelimiters)
+        {
+            char c = _buffer[index];
+            return InHump(c, wordDelimiters);
+        }
+
+        private bool InHump(char c, string wordDelimiters)
+        {
+            return !char.IsWhiteSpace(c) && wordDelimiters.IndexOf(c) < 0 && char.IsLower(c);
+        }
+    }
+}