FEXPR mostly went of fashion because they could not be compiled and their effects were hard to understand. Every FEXPR can do arbitrary computation with the for

FEXPR mostly went of fashion because they could not be compiled and their effects were hard to understand. Every FEXPR can do arbitrary computation with the forms they get passed. Thus each could do non-standard control flow and non-standard evaluation. A macro has the advantage that the generated code usually can be inspected and (for a compiled Lisp) the transformation is only done once. THE syntax of a macro form can already be checked at compile time. A FEXPR only showed usage errors at runtime.