mapping ctrl-d to single shift+tab

[lucantan]

Summary

in VIM, i am using ctrl-d to enable single shift+tab in insert mode (default vim behavior)
is there anyway to enable that?

default ctrl-d currently is to remove all empty spaces of current line and moved the cursor to the beginning of the line

Environment

• Operating system : (e.g. Ubuntu Gnome 15.04 64bit)
• Web browser : (e.g. Firefox 44.0.2)
• Version or revision of Jupyter Notebook : (e.g. 4.1 or 620fb29)
• Revision of jupyter-vim-binding : (e.g. 5a057d6)

Behavior

ctrl-d in vim is default to single shift+tab

Expected

expected to have same behavior for ctrl-d in vim and vim_binding in jupyter notebook

Actual

currently when we do ctrl-d, it is deleting all empty spaces and move cursor to beginning of the line

Step by step procedure

1. Start local Jupyter Notebook by jupyter notebook

2. Access http://localhost:8888/

3. create a cell

4. enter 3 tabs

5. enter ctrl-d
   now, the cursor will be moved to beginning of the line

6. enter 3 tabs

7. enter shift-tab
   now the cursor will be moved one tab space to the left

What you have done to solve the issue

added below in
~/.jupyter/custom/custom.js
without help

CodeMirror.Vim.map("Ctrl-D", "shift-tab", "insert");
or
CodeMirror.Vim.map("C-D", "shift-tab", "insert");
or
CodeMirror.Vim.map("Ctrl-D", "Shift-Tab", "insert");
or
CodeMirror.Vim.map("C-D", "Shift-Tab", "insert");