Alternative processing by python

README.md

@@ -24,14 +24,26 @@ endfunction
 git clone https://github.com/retorillo/json-ponyfill.vim ~/.vim/bundle/json-ponyfill.vim
 ```
 
-## Displaying progress bar
+## Performance problem and workarounds
 
-`json_ponyfill#json_decode` will take a long time when parsing large JSON.
+`json_ponyfill#json_decode` and `json_ponyfill#json_encode` will take a long
+time working with large JSON.
 
 Of course my code may be not sophisticated, but originally Vim Script is not
 good for large processing.
 
-In this case, consider to use `json_ponlyfill#json_decode(json, { 'progress': 1 })`
+Consider to use the following workarounds:
+
+### Using python if possible
+
+Use `json_ponyfill#json_decode(json, { 'python': 1 })`
+to use python if possible.
+
+Python can process faster than Vim Script.
+
+### Displaying progress bar
+
+Use `json_ponyfill#json_decode(json, { 'progress': 1 })`
 to display progress bar like below:
 
 ```
@@ -42,6 +54,12 @@ json_decode  50% [=========================.........................]
 wipe previously printed all echo message out.  See `:h redraw`, `:h messages`,
 `:h echomsg`, and `:h echoerr` to learn more.
 
+### Combining the above workarounds
+
+Of course, the above options can be combined like:
+`json_ponyfill#json_decode(json, { 'progress': 1, 'python': 1 }`.
+But note that progress option will be ignored if python is available.
+
 ## Unit testing (For plugin developers)
 
 `test/test.vim` is a bit useful snippet for unit testing.

autoload/json_ponyfill.vim

@@ -0,0 +1,25 @@
+let s:cpo = &cpo
+set cpo&vim
+
+function! json_ponyfill#json_decode(val, ...)
+  let option = len(a:000) > 0 ? a:000[0] : {}
+  if has_key(option, 'python')
+    \ && option.python
+    \ && json_ponyfill#python#ready()
+    return json_ponyfill#python#json_decode(a:val)
+  endif
+  return json_ponyfill#native#json_decode(a:val, option)
+endfunction
+
+function! json_ponyfill#json_encode(val, ...)
+  let option = len(a:000) > 0 ? a:000[0] : {}
+  if has_key(option, 'python')
+    \ && option.python
+    \ && json_ponyfill#python#ready()
+    return json_ponyfill#python#json_encode(a:val)
+  endif
+  return json_ponyfill#native#json_encode(a:val, option)
+endfunction
+
+let &cpo = s:cpo
+unlet s:cpo

autoload/json_ponyfill/python.vim

@@ -0,0 +1,42 @@
+let s:cpo = &cpo
+set cpo&vim
+
+function! json_ponyfill#python#ready()
+  if !has('python')
+    return 0
+  endif
+python << endpython
+import vim;
+try:
+  __import__('json');
+  vim.command('let ready = 1')
+except ImportError:
+  vim.command('let ready = 0')
+endpython
+  return ready
+endfunction
+
+function! json_ponyfill#python#json_decode(value)
+  let bind = {}
+python << endpython
+import vim;
+import json;
+bind = vim.bindeval('bind');
+bind.update({'value': json.loads(vim.eval('a:value'))});
+endpython
+  return bind.value
+endfunction
+
+function! json_ponyfill#python#json_encode(value)
+  let bind = {}
+python << endpython
+import vim;
+import json;
+bind = vim.bindeval('bind');
+bind.update({'value': json.dumps(vim.eval('a:value'))});
+endpython
+  return bind.value
+endfunction
+
+let &cpo = s:cpo
+unlet s:cpo

test/test.vim

@@ -61,13 +61,13 @@ call s:describe("json_ponyfill#stack")
   call s:itshouldeql("json#stackpeek",
     \ json_ponyfill#stack#peek(s:stack),
     \ "bar")
-  
+
   let s:stack = [ "foo", "bar" ]
   call json_ponyfill#stack#push(s:stack, "baz")
   call s:itshouldeql("json_ponyfill#stack#push",
     \ json_ponyfill#stack#peek(s:stack),
     \ "baz")
-  
+
   let s:stack = [ "foo", "bar" ]
   call s:itshouldeql('json_ponyfill#stack#pop #1',
     \ json_ponyfill#stack#pop(s:stack),
@@ -141,7 +141,7 @@ call s:describe("json_ponyfill#native#json_encode")
   call s:itshouldeql('decode object #3',
     \ json_ponyfill#native#json_decode('{ "foo" : { "bar" : "baz", "baz": [ 1, 2, 3 ] } }'),
     \ { "foo": { "bar": "baz", "baz": [1, 2, 3] } })
-  
+
   let throwexception = 0
   try
     call json_ponyfill#native#json_decode('{ "foo" ":" "baz" }')
@@ -153,5 +153,14 @@ call s:describe("json_ponyfill#native#json_encode")
   endtry
 call s:enddescribe()
 
+call s:describe("json_ponyfill#python")
+if json_ponyfill#python#ready()
+  call s:itshouldeql('decode', json_ponyfill#python#json_decode('{ "foo": "bar" }'), { "foo": "bar" })
+  call s:itshouldeql('encode', json_ponyfill#python#json_encode({ "foo": "bar" }), '{"foo": "bar"}')
+else
+  s:failing('No python or json module. Skipped python testcase.', '-python', '+python')
+endif
+call s:enddescribe()
+
 let &cpo = s:cpo
 unlet s:cpo