I'm planning to stop bugging this mailing list, but before that, please allow me a final question. That is related to what I have done so far.
My current implementation is the following.
```
@excluded@
type T;
identifier i;
position p;
@@

(
 T i@p(...);
|
 extern T i@p;
|
 T i@p(...,......);
)


@r@
type T;
identifier i;
expression E;
position q != excluded.p;
position p : script:python(i) { p[0].current_element == i};
attribute name __randomize_layout;
@@

(
 T i@q@p;
|
 T i@q@p=E;
)

@rr@
type T;
identifier i;
expression E;
attribute name __randomize_layout;
@@

(
 T i;
|
 T i=E;
)

@script:python@
i << excluded.i;
@@
print (i)
```
It is a suboptimal version of Julia's last proposition.
It happens that in a file a statement I expect to be matched is not detected.
Troubleshooting the issue, I see a behavior that does not fit the model I have in my mind. This suggests to me that things (coccinelle under the hood mechanisms) are more complicated than I think.
back to the point:
Running the script and printing only the rule "rr", which is the same as "r" without positions, the results presents a set of entries containing the entry I'm interested in.
Running the same script but printing only the rule "excluded", I see that the result is an empty set.
Finally, running the script using only the "r" rule, the entry I'm interested in is not there.