Problem with bytes &size=self.offset()

[sethhall]

I'm not sure if this is related to some expression parsing issue in &size attributes on bytes fields or something else, but I'm seeing a weird behavior...

This works as you might expect (parse 3 bytes then calculate the crc32 for those bytes)...

module Test;
import spicy;

public type X = unit {
    a: uint8;
    b: uint8;
    c: uint8;
    : bytes &size=3 &parse-at=self.input() {
        self.crc32 = spicy::crc32_add(spicy::crc32_init(), $$);
    }
    var crc32: uint64;
};

But this doesn't work (even though self.offset() returns 3)...

module Test;
import spicy;

public type X = unit {
    a: uint8;
    b: uint8;
    c: uint8;
    : bytes &size=self.offset() &parse-at=self.input() {
        self.crc32 = spicy::crc32_add(spicy::crc32_init(), $$);
    }
    var crc32: uint64;
};

It seems that self.offset() used in the &size field ends up returning zero?

[rsmmr]

Oh ... Never thought about this but the way offset() is currently implemented, means its works only inside hooks, not from attributes. We should fix that.

[rsmmr]

It's a different issue actually: it's the &parse-at that gets applied before offset() is evaluated, meaning offset is now zero indeed. That's not intuitive, fixing.

[sethhall]

Ok, that bug is pretty unintuitive. :)