====== VIM - Leader ======

vim allows a set of keys to be mapped as an alias to a different command in the **<nowiki>~/.vimrc</nowiki>** file.

For example:

<code vim>
:nnoremap -d dd
</code>

<WRAP info>
**NOTE:**  This maps that when **-d** is typed, it actually runs the **dd** command.

In this example,it would delete the current line.

  * **:nnoremap**:   denotes normal mode.

Why not just map **d** to **dd**.  Surely this would save typing a keystroke.

  * This could be dangerous, as just typing a single character could delete data.
  * As a safety precaution it is best to have to type this extra character.
  * But what if in future you want to change this prefix character?
  * One way is to manually modify each alias.  Alternatively, use a leader.
</WRAP>

----

===== Use a leader =====

<code vim>
:let mapleader = "-"
</code>

<WRAP info>
**NOTE:**  Sets the leader to a hyphen.
</WRAP>

----

<code vim>
:nnoremap <leader>d dd
</code>

<WRAP info>
**NOTE:**  Defining the leader in one place makes it easy to change later.
</WRAP>

----

===== Local Leader =====

Vim has a second "leader" key called **local leader**.

  * This is meant to be a prefix for mappings that only take effect for certain types of files, like Python files or HTML files.

<code vim>
:let maplocalleader = "\\"
</code>

<WRAP info>
**NOTE:**  

  * **<nowiki>\\</nowiki>** is used, and not just **<nowiki>\</nowiki>**  because <nowiki>\</nowiki> is the escape character.

The <localleader> can be used just like <leader>.

</WRAP>

----

===== Help =====

<code vim>
:help mapleader
:help maplocalleader
</code>

----

===== References =====

https://learnvimscriptthehardway.stevelosh.com/chapters/06.html

https://vim.fandom.com/wiki/Mapping_keys_in_Vim_-_Tutorial_(Part_1)

https://vimhelp.org/syntax.txt.html