symbol-function

(symbol-function symbol)

Returns the function value bound to symbol in the function namespace -- the same value #'name denotes. The result can be passed to funcall/apply or stored. Because rontolisp is a Lisp-2, this looks only in the function namespace, never at a variable of the same name. A quoted symbol literal ((symbol-function 'car)) resolves at compile time in the compilers; a runtime-computed symbol resolves late through the compiled name registry and answers the same function value -- functionp is true of it, it prints its registered name, and an undefined name (nil, t, keywords and a name fmakunbound retired included) signals undefined-function at symbol-function itself, catchable by that class on every backend.

symbol-function is also a setf place: (setf (symbol-function 'name) fn) installs fn as the symbol's global function definition -- defining an alias for an existing function, or replacing one. In the compilers a call site the compiler already bound directly keeps the original function (fmakunbound's divergence); a name bound ONLY this way is fully late-bound: before the assignment runs, a call, #'name, symbol-function and fdefinition signal undefined-function naming it and fboundp answers false, on every backend; afterwards #'name is the installed function itself.