How to compile CoffeeScript just-in-time in vim? - vim

Question

I can easily vsplit vim window into two(left and right).
How to config vim to:
edit CoffeeScript in the left-window
view compiled JavaScript result in the right-window
view error message at the status-line
When I type in the left-window, the right-window and status-line should update JIT.
For example:
========================================================================
alert "hello" | alert("hello");
alert "world | alert;
|
========================================================================
missing ", starting on line 2
Just like http://coffeescript.org/ -> Try CoffeeScript.

Answer 1

I don't just use vim for this, I use a combination of GNU screen, GNU source-highlight and GNU watch. However, you need to have the version of screen that has the vertical split patch.
After starting screen, I'll hit Ctrl+ACtrl+C to create a second shell, then use Ctrl+AShift+\ to create a vertical split, then Ctrl+ATab to swap over to the new split and Ctrl+ACtrl+A to swap the split over to the new shell. In that shell, I run:
$ mkdir compiled
$ coffee -w -c -o compiled/ *.coffee &
That will run coffee in watch mode, which watches the source file (*.coffee) or folder for changes, and automatically recompiles changed *.coffee files and places the resulting .js files in the compiled folder.
Now, I will run $ watch --color -n 1 colorize compiled/main.js to display the contents of the compiled file I'm interested in, enabling ANSI colorized output.
That script file that I have called colorize is just a wrapper around source-highlight that automatically detects the language of the source file and applies appropriate syntax highlighting.
Then I use Ctrl+ACtrl+Tab to move back over to the first split, and fire up vim main.coffee and start editing away.
As I edit the coffeescript file, the compiled changes show up on the right hand side.
Errors are a little trickier, as they get spit out from the background coffee -w job. They will show up, but sometimes the watch command will overwrite the errors, and sometimes the errors will mess up the screen. When that happens, a quick Ctrl+L to tell bash to redraw the screen fixes things up.
Hope that's of some help.

Answer 2

vimrc config
set autoread
aug coffee
au!
au BufNewFile,BufRead *.coffee setf coffee.python
au FileType coffee.python setl makeprg=coffee\ -c\ %
au FileType coffee.python setl errorformat=Error:\ In\ %f\\,\ %m\ on\ line\ %l,
\Error:\ In\ %f\\,\ Parse\ error\ on\ line\ %l:\ %m,
\SyntaxError:\ In\ %f\\,\ %m,
\%-G%.%#
au BufWritePost *.coffee silent! make! | copen | redraw!
aug END
Note: If you like JIT, try CursorHold instead of BufWritePost.
open file
$ vim -O code.{coffee,js}
run ex command
:w