define function on-demand?

[Comperio]

I'm just trying to clean up my code a bit. I like to wrap my own functions in an NSH file that I can !include when I need them using macros and return varaibles. (I find this much more convenient than using stack commands within a section or function.)

My list of functions (and NSH files) keeps growing. I'd like to take the ones I use most often and put then into a single NSH file. However, I might not use every single function declared in an NSH file.

I'd like to know if anyone has any tricks of defining a function "on demand". In other words, I want to automatically create a function only when needed. I thought perhaps I could encapsulate the function within "!ifdef" statements, but I'm not sure if that's the right way to go.

Here's an example of a basic NSH file layout that I currently use. Any advice would be appreciated. Thanks!
______________________________________________________
!macro MyFunc Return_var Input_var
push ${Input_var}
Call MyFunc
Pop ${Return_var}
!macroend

!define CoolFunction "!insertmacro MyFunc"

Function MyFunc
Exch $0
push $1
; do stuff with $0
; store result in $1
exch $1
exch
pop $0
FunctionEnd