[aidenn0]

An equivalent to iterate/loop where each compound form need be replaced by an anonymous function and each binding is replaced by a dictionary entry could be implemented completely as a function. Is this also new syntax?

If not, how is the macro different other than implicitly changing the evaluation?

for a more simple example, why is the idiom CALL-WITH-FOO (implemented as a function) not syntax while WITH-FOO (implemented as a macro) is? What precisely is syntax is somewhat nebulous (if I use a regex library in C, have I added syntax to the language? Regexes certainly are syntax, despite being wrapped in a C string).