I think calling the call stack an AST is stretching things a bit :-P. Turbo Pascal (and most of Wirth's own compilers) is a simple recursive descent compiler th

I think calling the call stack an AST is stretching things a bit :-P. Turbo Pascal (and most of Wirth's own compilers) is a simple recursive descent compiler that emits code almost as soon as it scans a token and it keeps very little information around.