@Override
public Function<Object[], ?> visit(LambdaExpression<?> e) {
final Function<Object[], ?> f = e.getBody().accept(this);
int size = e.getParameters().size();
List<Function<Object[], ?>> ppe = new ArrayList<>(size);
for (ParameterExpression p : e.getParameters()) ppe.add(p.accept(this));
Function<Object[], Object[]> params =
pp -> {
Object[] r = new Object[ppe.size()];
int index = 0;
for (Function<Object[], ?> pe : ppe) {
r[index++] = pe.apply(pp);
}
return r;
};
return f.compose(params);
}
@Override
public Function<Object[], ?> visit(MemberExpression e) {
final Member m = e.getMember();
Expression ei = e.getInstance();
final Function<Object[], ?> instance = ei != null ? ei.accept(this) : null;
int size = e.getParameters().size();
List<Function<Object[], ?>> ppe = new ArrayList<>(size);
for (ParameterExpression p : e.getParameters()) ppe.add(p.accept(this));
Function<Object[], Object[]> params =
pp -> {
Object[] r = new Object[ppe.size()];
int index = 0;
for (Function<Object[], ?> pe : ppe) {
r[index++] = pe.apply(pp);
}
return r;
};
Function<Object[], ?> field =
t -> {
try {
return ((Field) m).get(instance == null ? null : instance.apply(t));
} catch (IllegalArgumentException | IllegalAccessException ex) {
throw new RuntimeException(ex);
}
};
Function<Object[], ?> method =
t -> {
Object inst;
if (instance != null) {
inst = instance.apply(t);
} else inst = null;
try {
Object[] pp = params.apply(t);
return ((Method) m).invoke(inst, pp);
} catch (IllegalAccessException
| IllegalArgumentException
| InvocationTargetException ex) {
throw new RuntimeException(ex);
}
};
Function<Object[], ?> ctor =
t -> {
try {
return ((Constructor<?>) m).newInstance(params.apply(t));
} catch (InstantiationException
| IllegalAccessException
| IllegalArgumentException
| InvocationTargetException ex) {
throw new RuntimeException(ex);
}
};
Function<Object[], ?> member;
if (m instanceof Field) member = field;
else if (m instanceof Method) member = method;
else member = ctor;
return member; // .compose(params);
}
