Repeatedly calls macroexpand-1 on form until it no longer
represents a macro form, then returns it.
Source
(defnmacroexpand"Repeatedly calls macroexpand-1 on form until it no longer
represents a macro form, then returns it."[formenv](loop[formform](let[mform(macroexpand-1formenv)](if(=mformform)mform(recurmform)))))