Write a simple text editor, which stores and displays a string of characters using the positional list ADT, together with a cursor object that highlights a position in the string. The editor must support the following operations:
• Left: Move cursor left one character (do nothing if at beginning).
• Right: Move cursor right one character (do nothing if at end).
• Insert c: Insert the character c just after the cursor.
• Delete: Delete the character just after the cursor (if not at end).