vimdecdef
                                 Eddie Carle
                              eddie@erctech.org

INTRODUCTION

vimdecdef is a simple vim script that facilitates transitioning between
declarations and definitions in C++. The script can take a declaration and
either find it's definition or create one if it doens't exist. The definitions
will take into account scope and template. All script actions will utilize one
of two files. The header file and the source file. Initilially one should
always load a header file. If for example one executed ':e include/file.hpp'
then the script will automatically assume that the source file is located at
src/file.cpp. The script has a single bindable command that preforms the
following functions based on it's situation:

 * If the cursor is on a normal function activating the script will search the
   source file for it's definition. If the definition does not exist, it will
   append one at the bottom of the source file and leave the cursor there.
 * If the cursor is on an inline or template function activating the script will
   search the source file for it's definition. If it is found in the source
   file, the cursor will be positioned there. If the definition is not found in
   the source file the script will try to find it in the header file. If it is
   found in the header file, the cursor will be positioned there. If it is not
   found, one will be appended to the bottom of the header file insuring that it
   stays within any closing #endif that may exist.
 * If the cursor is on a global object or static data member the script will
   search the source file for it's definition. If the definition does not exist,
   it will append one at the bottom of the source file and leave the cursor
   there.
 * If the script's last action ended in a definition in the header file,
   activating it again will move the cursor back to the original declaration
   that caused the previous move regardless of the cursors current position.
 * Activating the script at any point in the header file that doesn't fall under
   any of the above circumstances will result in switching to the source file at
   it's last cursor position.
 * Activating the script while in the source file will always result in
   switching back to the header file at it's last cursor position.

USAGE

First copy vimdecdef.vim into your ~/.vim/ftplugin/cpp directory. You may want
to enable hidden (:set hidden) while using the script as it tends to work in a
prettier way. You will want to set up a map for the command. I like having it
bound to <F7> so to accomplish that it's a simple matter of:

map <silent> <F7> <Plug>vimdecdef

With everything setup we can get started. Note all paths are relative. Say we
have a header file located at include/somelibrary/file.hpp. Our first step
will be to load it into vim. Always load the header file first.

vim include/somelibrary/file.hpp

Now the script will assume the source file is located at src/file.cpp. Simple
press <F7> at a blank line and the source file will be loaded. Press it again
and you will switch back to the header file. Hit <F7> at a declaration, and
special things discussed above will happen.

There are three customizable options: source file prefix, source file
extension and whether or not to actually use a separate source file.
The default definitions follow.

let g:vimdecdefSourceExtension = "cpp"
let g:vimdecdefSourcePrefix = "src/"
let g:vimdecdefSourceSeparate = 1

LIMITATIONS

Obviously this script is not without it's limitations. Here are a few that have
been noticed. Feel free to contact me with others you may notice. Or better yet,
fix them!

 * Unable to determine the scope identifier for return types and object types.
   I would really like a solution, but it escapes me. When the script generates
   a definition for you, you must edit the type/return type manually.
 * Declarations MUST be not be split up into multiple lines in your code. This
   means that class declarations must have the class and template part on the
   same line. Function declarations must have all template stuff, return type,
   arguments, modifiers, etc all on the same line.
 * You must use the "bracket on it's own line" style. Meaning
   
   class someClass
   {

   };

   works, but not

   class someClass {

   };