Unnecessary return null + capital Void

[HorridModz]

In 11.3.1 (page 178 in physical book), there is this code:

@Override
public Void visitBlockStmt(Stmt.Block stmt) {
    beginScope();
    resolve(stmt.statements);
    endScope();
    return null;
}

I believe there's two things wrong with this code.

1. The data type (void) is capitalized - it should be "void", not "Void"
2. There is an unnecessary 'return null;' at the end.

[prggTheProgrammer]

I don't think this is wrong. It is explained in chapter 8. Because this method implements the interface method E visitBlockStmt and E is of type Void it needs to return null.

class Interpreter implements Expr.Visitor<Object>,
                             Stmt.Visitor<Void> {

The reason this can't be Stmt.Visitor<void> is explained in the note: Java doesn’t let you use lowercase “void” as a generic type argument for obscure reasons having to do with type erasure and the stack. Instead, there is a separate “Void” type specifically for this use. Sort of a “boxed void”, like “Integer” is for “int”. So because of the <Void> the return type needs to be Void and the method must have return null;

[HorridModz]

Sorry for the misunderstanding! Thanks for correcting me.

[petejerky]

Respect!!!!!On 15 Apr 2023, at 3:43 am, HorridModz @.***> wrote: Sorry for the misunderstanding! Thanks for correcting me.

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[HorridModz]

@petejerky ?

[petejerky]

YesOn 17 Apr 2023, at 1:18 pm, HorridModz @.***> wrote: @petejerky ?

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