CDep fun.

gistfile1.txt

THIS IS THE ORIGINAL BEHAVIOR (all fixed now).

   $define(myecho,$echo($0)) 
   $define(myecho2,$myecho($0))

   $echo(comma=$,)
   $myecho(comma=$,)
   $myecho(comma=$$$,)
   $myecho2(comma=$$$,)

prints:

   comma=,
   comma=
   comma=,
   comma= 
   
...but wait, if I need to escape it as "$$$," when calling myecho, does that mean I just need to add an
extra $$ when calling myecho2?

No. In fact you need to write _six_ $ signs to get 3 dollar signs by the time myecho evaluates something,
and of course you need to escape the actual comma too, so the magic sequence to make myecho2 print a ',' is in fact:

   $myecho2(comma=$$$$$$$,)

and in general, if you want to escape something, you need to add (2^k)-1 dollar signs in front of it, where k is
the level of the call tree where you want to use it.

Furthermore, this:

   $define(funcABC,
     $echo(ABC!)
     $echo(ABC-0: $0)
     $echo(ABC-1: $1)
     $echo(ABC-2: $2)
     $echo(ABC done!)
   )

   $define(funcAB,
     $echo(AB!)
     $echo(AB-0: $0)
     $echo(AB-1: $1)
     $funcABC($0,$1)
     $0 $// ignored return value
     $echo(AB done!)
   )

   $funcAB(A,B)
   $funcAB(A$,B,C)
   $funcAB(A$$$,B,C)
   $funcAB(A$echo(holy side effect batman!),B)
   $funcAB(A$$echo$(holy side effect batman!$),B) 
   
prints:

    AB!
    AB-0: A
    AB-1: B
    ABC!
    ABC-0: A
    ABC-1: B
    ABC-2:
    ABC done!
    AB done!

    AB!
    AB-0: A
    AB-1: C
    ABC!
    ABC-0: A
    ABC-1: C
    ABC-2:
    ABC done!
    AB done!

    AB!
    AB-0: A,B
    AB-1: C
    ABC!
    ABC-0: A
    ABC-1: C
    ABC-2:
    ABC done!
    AB done!

    holy side effect batman!
    AB!
    AB-0: A
    AB-1: B
    ABC!
    ABC-0: A
    ABC-1: B
    ABC-2:
    ABC done!
    AB done!

    AB!
    holy side effect batman!
    AB-0: A
    AB-1: B
    holy side effect batman!
    ABC!
    ABC-0: A
    ABC-1: B
    ABC-2:
    ABC done!
    holy side effect batman!
    AB done!