Adding Atex Markdown Headers in Vim

Question

Is there a way to make it so that

This is a header
=<tab>

converts into

This is a header
================

in all files who filetype is markdown?

Answer 1

Likely it can be done with =TAB, but another approach is:

1. type your header, then ESCVyESC (copy the whole line in Visual mode)
2. paste
3. jVr= (move down, select whole line, replace it with =.

Then You can create a macro or an imap or nmap for it.

Another approach is (after typing your header and getting back to normal mode is: :t.|s/./=/g (ex mode copy line bellow and replace every character on it with =.

Answer 2

You could do it this way:

This is a header
=

On the line with = type:

<ESC>Vly5p

1. V puts vim into visual mode.
2. l (letter l) moves the cursor to the left.
3. y copies the =.
4. 5 is the number of =s you want.
5. p inserts the =s.