Efl.Ui.Textbox does not handle Ctrl+Backspace & Ctrl+Delete correctly, also the behaviour is undefined.
Below are two GIFs that shows how Efl.Ui.Textbox currently work:
Fig 1: here i was pressing Ctrl+Arrows to jump word by word, then i pressed Ctrl+Backspace which jumped to the beginning; while it should remove a word before caret position
Fig2: here i was pressing Ctrl+Delete it should remove a word after caret, but the caret jumped to the beginning of text and removed the first word
The following shows how Ctrl+Backspace and Ctrl+Delete should delete a word before and after respectively!
Fig3: here i was pressing Ctrl+backspace to delete a word before the caret, and Ctrl+Delete to delete a word after the caret.