This problem is not about the greatest editor in the world; it is just a tribute.
The Tenacious eDitor is an attempt to clone to power of a certain modal editor. However, it is notoriously bug-ridden. You've been asked to replace Kyle (who quit the devteam) and help with fixing some of the bugs.
The main problem with the current release of td, as it is commonly referred to, is that it cannot differentiate between text on a line and commands. Whenever a user wants to type an x, the editor interprets it as a command to delete the last character. This is problematic. Thankfully, commands are case-sensitive, and each letter is at most a single command (sometimes uppercase, sometimes lowercase), so one can manage to write any given line of text as long as it's allowed to look like something written by a fourteen-year-old hacker wannabe.
Editing occurs in an edit buffer, which starts out empty. The cursor in td rests in gaps, locations surrounding each printed character. When a non-command character is entered, the character is inserted to the right of the cursor's current location and the cursor moves to the gap to the right of the new character. (This is the standard behavior of most editors.) A line with no characters has a single gap. A line with a single printable character has two (one before and one after), a line with two printable characters has three, and so on.
The currently-implemented commands are:
|Command keys||Result||Cursor location after operation|
|x||Delete the character immediately to the left of the cursor||One gap to the left|
|K||Delete all non-spaces to the left of the cursor, stopping at the first space encountered or the beginning of the line; if the previous character is a space, delete nothing||The gap to the right of the "stop" character|
|c||Duplicate the character to the left of the cursor, inserting it to the right of the cursor||The gap to the right of the duplicate character (one right)|
|D||Duplicate all non-spaces to the left of the cursor, stopping at the first space encountered or the beginning of the line and inserting them to the right of the cursor; if the previous character is a space, duplicate nothing||The gap to the right of the rightmost duplicate character|
|R||Reverse all non-spaces to the left of the cursor, stopping at the first space encountered or the beginning of the line; if the previous character is a space, reverse nothing||No change|
|p||Delete all characters to the left of the cursor||Leftmost gap|
|W||Delete all characters to the right of the cursor||No change|
|h||Move the cursor one gap to the left||One gap to the left|
|L||Move the cursor one gap to the right||One gap to the right|
|f||Move the cursor to the first gap on the line||Leftmost gap|
|G||Move the cursor to the last gap on the line||Rightmost gap|
|any non-command character||Insert the character into the edit buffer to the right of the cursor||One gap to the right|
When a character is added internally to a line of text, all subsequent characters shift to the right (as in "insert mode"); when characters are deleted from anywhere other than the end of a line, all subsequent characters shift to the left.
Any commands which cannot properly do anything (attempting to move past the first or last gap, deleting characters when none exist, and so on) do nothing. They do not show up as printed characters.
Each line represents a different session of td; at the beginning of a new session, the edit buffer is empty.
Given a series of keystrokes by a user, can you determine what text actually results if it were entered in the current version of td?