Thanks Feng.
I want to access elements before evaluation. Use your example:
Define:
public static List<Long> myFunc() { return Arrays.asList(1L, 2L); }
public static Long myFunc2(Long i) { return i - 1l }
I want build expressions as the following:
List<Expression> ret = new ArrayList();
MethodCallExpression mce = Expressions.call(SqlFunctions.class,"myFunc");
// how to make each element an expression?
for (Expression expr : mce) {
ret.dd(Expressions.call(SqlFunctions.class, "myFunc2", expr));
}
return ret;
As you can see, I know "myFunc" returns a list, so I want to make each
element of that list an expression so I can continue manipulating them.
Eventually they will be used to generate code.
-Rui
On Mon, Dec 30, 2019 at 9:29 PM Feng Zhu <wellfeng...@gmail.com> wrote:
> >
> > Basically I know the function return a list so I want to access each
> > element of it. Ideally I can get a List<Expression> ret =
> > Expressions.call(FindMethod("myFunc"))
> >
> Can you elaborate on what do you want? i.e., *List<Expression> ret*
> If you want to get the element of a method call result, you can evaluate
> the expression and cast it to list.
>
> For example, assume "myFunc" in SqlFunctions.
>
>
>
> * public static List<Long> myFunc() { return Arrays.asList(1L, 2L); }*
>
>
> * MethodCallExpression mce = Expressions.call(SqlFunctions.class,
> "myFunc"); List<Long> ret = (List<Long>) Expressions.evaluate(mce);*
>
> Best,
>
> Rui Wang <amaliu...@apache.org> 于2019年12月31日周二 下午12:14写道：
>
> > Hi community,
> >
> > Let's say I define a function like this:
> >
> > List<Long> myFunc() {
> > // function body
> > // do something
> > // return a list of long
> > }
> >
> > Then by linq4j library, I can
> >
> > Expression ret = Expressions.call(
> > FindMethod("myFunc")
> > )
> >
> >
> > my question is, how to make the returned expression of the call to be a
> > list, or something equivalent?
> >
> > Basically I know the function return a list so I want to access each
> > element of it. Ideally I can get a List<Expression> ret =
> > Expressions.call(FindMethod("myFunc"))
> >
> >
> > -Rui
> >
>
