ftdetect
author |
Steve Losh <steve@stevelosh.com> |
date |
Sun, 13 Nov 2011 19:12:41 -0500 |
parents |
(none) |
children |
2b0626af776b |
Detecting Filetypes
===================
Let's create a Potion file we can use as a sample as we're working on our
plugin. Create a `factorial.pn` file somewhere and put the following Potion
code inside it:
factorial = (n):
total = 1
n to 1 (i):
total *= i.
total.
10 times (i):
i string print
'! is: ' print
factorial (i) string print
"\n" print.
This code creates a simple factorial function and calls it ten times, printing
the results each time. Go ahead and run it with `potion factorial.pn`. The
output should look like this:
0! is: 0
1! is: 1
2! is: 2
3! is: 6
4! is: 24
5! is: 120
6! is: 720
7! is: 5040
8! is: 40320
9! is: 362880
Detecting Potion Files
----------------------
Open `factorial.pn` in Vim and run the following command:
:set filetype?
Vim will display `filetype=` because it doesn't know what a `.pn` file is yet.
Let's fix that.
Create `ftdetect/potion.vim` in your plugin's repo. Put the following lines
into it:
augroup potion_detect
au!
au BufNewFile,BufRead *.pn set filetype=potion
augroup END
This creates an autocommand group with one autocommand inside: a command to set
the filetype of `.pn` files to `potion`. Pretty straightforward.
Close the `factorial.pn` file and reopen it. Now run the previous command
again:
:set filetype?
This time Vim displays `filetype=potion`. When Vim started up it loaded the
autocommand group inside `~/.vim/bundle/potion.vim`, and when it opened
`factorial.pn` the autocommand fired, setting the `filetype` to `potion`.
Now that we've taught Vim to recognize Potion files we can move on to actually
creating some useful behavior in our plugin.
Exercises
---------
Read `:help ft`. Don't worry if you don't understand everything there.
Read `:help setfiletype`.
Modify the Potion plugin's `ftdetect/potion.vim` script to use `setfiletype`
instead of `set filetype`.