macroexpand-1

(macroexpand-1 form)

Expands form once when its operator is a user macro (defined with defmacro) or a built-in macro (the names rontolisp:list-macros reports), and returns the form unchanged otherwise. Only the top-level operator is expanded; subforms are left alone.

Deviations from Common Lisp: macroexpand-1 supplies no second expanded-p value — compare the result with the input to detect expansion — and takes no environment argument. On the compilation path the argument must be a literal quoted form: the CLI folds the call to its expansion at compile time (the macro table does not exist at runtime in compiled output), so a computed argument is a compile error, and the runtime eval of a compiled program does not know macroexpand-1.

A non-macro form is returned as-is: