But no, you cannot directly write: f(x, y, g(a)) where a is the replacement string because you don’t know what a is when the inner function g is evaluated first. You need: f(x, y, g(h(x, y))) where h is the matching function, g is the transform, f is the replacement of the third argument into the x source text, and y is the pattern. I presume the y is going to be the same value here but that isn’t required.
“a” is actually probably going to be an array of text here, its evaluation producing the replacement string that f requires. a is not the replacement string itself.
David J.