VIM: how to execute the contents of a buffer? -

I have an existing vim script that I am developing in my current buffer and I want to execute it. Is there an easy way to do this?

After a long search, I have only found two related methods, but not exactly what I want to do:

a) To use it on the "source" command I need to save the contents in the file for the first time and then it is returned to the "source", which does not look simple

b) call on my command "call" command - I do not want to call my function, I I want to execute the file, which defines several functions and some of the code Use

outside of others:

 :% y " (Optionally: GGIG): @ "  
 This will copy entire buffer into the default register and then see  
:  y  And : help: @  (and : help category ).