private Function evaluateFunction(SEXP functionExp, Environment rho) {
if (functionExp instanceof Symbol) {
Symbol symbol = (Symbol) functionExp;
Function fn = rho.findFunction(this, symbol);
if (fn == null) {
throw new EvalException("could not find function '%s'", symbol.getPrintName());
}
return fn;
} else {
SEXP evaluated = evaluate(functionExp, rho).force(this);
if (!(evaluated instanceof Function)) {
throw new EvalException(
"'function' of lang expression is of unsupported type '%s'", evaluated.getTypeName());
}
return (Function) evaluated;
}
}
private SEXP do_inherited_table(
Context context, SEXP class_objs, SEXP fdef, SEXP mtable, Environment ev) {
SEXP fun = methodsNamespace.findFunction(context, Symbol.get(".InheritForDispatch"));
return context.evaluate(FunctionCall.newCall(fun, class_objs, fdef, mtable), ev);
}