Update lang#coffeescript layer (#4229)

autoload/SpaceVim/layers/lang/coffeescript.vim

@@ -32,7 +32,13 @@
 "   SPC l s l       send current line
 "   SPC l s s       send selection text
 " <
-"
+
+
+if exists('s:coffee_interpreter')
+  finish
+endif
+
+let s:coffee_interpreter = 'coffee' . (s:SYS.isWindows ? '.CMD' : '')
 
 let s:SYS = SpaceVim#api#import('system')
 
@@ -45,12 +51,12 @@ endfunction
 
 function! SpaceVim#layers#lang#coffeescript#config() abort
   call SpaceVim#plugins#runner#reg_runner('coffee', {
-        \ 'exe' : 'coffee' . (s:SYS.isWindows ? '.CMD' : ''),
+        \ 'exe' : s:coffee_interpreter,
         \ 'usestdin' : 1,
         \ 'opt': ['-s'],
         \ })
   " call SpaceVim#plugins#runner#reg_runner('coffee', 'coffee %s')
-  call SpaceVim#plugins#repl#reg('coffee', ['coffee' . (s:SYS.isWindows ? '.CMD' : ''), '-i'])
+  call SpaceVim#plugins#repl#reg('coffee', [s:coffee_interpreter, '-i'])
   call SpaceVim#mapping#space#regesit_lang_mappings('coffee', function('s:language_specified_mappings'))
 
 endfunction
@@ -99,3 +105,6 @@ endfunction
 function! s:filter_coffee_lint(lines, job) abort
   let a:lines = []
 endfunction
+function! SpaceVim#layers#lang#coffeescript#set_variable(var) abort
+  let s:coffee_interpreter = get(a:var, 'coffee_interpreter', s:coffee_interpreter)
+endfunction

doc/SpaceVim.txt

@@ -1752,7 +1752,6 @@ This layer also provides REPL support for coffeescript, the key bindings are:
   SPC l s s       send selection text
 <
 
-
 ==============================================================================
 LANG#CRYSTAL                                     *SpaceVim-layer-lang-crystal*
 

docs/layers/lang/coffeescript.md

@@ -10,6 +10,9 @@ description: "This layer is for CoffeeScript development, provide autocompletion
 - [Description](#description)
 - [Features](#features)
 - [Install](#install)
+- [Key bindings](#key-bindings)
+  - [Running current script](#running-current-script)
+  - [Inferior REPL process](#inferior-repl-process)
 
 <!-- vim-markdown-toc -->
 
@@ -33,3 +36,23 @@ To use this configuration layer, update custom configuration file with:
 [[layers]]
   name = "lang#coffeescript"
 ```
+
+## Key bindings
+
+### Running current script
+
+To running a coffeescript file, you can press `SPC l r` to run current file without loss focus,
+and the result will be shown in a runner buffer.
+
+### Inferior REPL process
+
+Start a `coffee -i` inferior REPL process with `SPC l s i`.
+
+Send code to inferior process commands:
+
+| Key Bindings | Descriptions                                     |
+| ------------ | ------------------------------------------------ |
+| `SPC l s b`  | send buffer and keep code buffer focused         |
+| `SPC l s l`  | send line and keep code buffer focused           |
+| `SPC l s s`  | send selection text and keep code buffer focused |
+