fixing mistakes in the command line

a lot of time ago, I copied these lines in my vimrc to fix some common mistakes:

nnoremap :W :w
nnoremap :Q :q
nnoremap :E :e

I don't remember where I took this suggestions, but it worked. Now I see I type a lot of times ":ag" instead of ":Ag", however as soon I started to add this new mapping I asked myself if this is really the correct way to deal with this kind of task... I searched on google for some better suggestions, but usually searching about vim's command line finds articles on starting vim from shell with arguments... -________-
In any case even further searches found nothing, so I'm asking here if someone knows what would be the correct way to "auto-fix" mistakes in the command line.

thanks in advance!


--
--
You received this message from the "vim_use" maillist.
Do not top-post! Type your reply below the text you are replying to.
For more information, visit http://www.vim.org/maillist.php

---
You received this message because you are subscribed to the Google Groups "vim_use" group.
To unsubscribe from this group and stop receiving emails from it, send an email to vim_use+unsubscribe@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.