When to be concerned w/ passing parameters in torquescript?

I suppose the two biggest factors would be whats being passed by copy and if the function call is inside a loop with many iterations. In the following situation I should be alright.

In the root main.cs file there are the following functions with the similar definitions:

function pushFront(%list, %token, %delim)
{
   if(%list !$= "")
      return(%token@ %delim@ %list);

   return(%token);
}

function pushBack(%list, %token, %delim)
{
   if(%list !$= "")
      return(%list@ %delim@ %token);

   return(%token);
}

I could write one function to replace both of these. The function push would handle both return statements based on an additional parameter.