A thing that AF lacks is a function to store the match of a regex. It would be really helpful in many situations, such as the ones in which you want to determine if the value of a parameter within a template was changed. For these and other situations, here is the "getmatch" function. Syntax is getmatch(pattern, text), the result is an array with the same properties as php function preg_match's third parameter.
For instance, suppose that you have "|parameter=value" and you want to check if it's changed. You can do
old := getmatch( "\|parameter=([^|}]+)", removed_lines)[1]; new := getmatch( "\|parameter=([^|}]+)", added_lines)[1];
and check new against old, depending on the context (the example is referred to a very basic situation).
Moreover, there might be situations when you also need another match. A case might be:
olds := getmatch( "\|([^=]+)=([^|}]+)", removed_lines); old_par := olds[1]; old_val := olds[2];
And so on. When dealing with small arrays you don't actually need a for loop or any other way to iterate over them.