Re: [PATCH v2 2/2] [GSOC] ref-filter: introduce enum atom_type

And I'd assume I am right in the following.

quoted

+ * ATOM_INVALID equals to the size of valid_atom array, which could help us
+ * iterate over valid_atom array like this:
+ *
+ *   for (i = ATOM_UNKNOWN + 1; i < ATOM_INVALID; i++) {

I find it far more intuitive to say

        for (i = 0; i < ATOM_INVALID; i++)

than having to say UNKNOWN+1.

In any case, the values should be indented, and a comment should
ensure that the final one stays at the end, perhaps like this.

        enum atom_type {
                ATOM_INVALID = -2,
                ATOM_UNKNOWN = -1,
                ATOM_REFNAME,
                ...
                ATOM_ELSE,
                ATOM_MAX /* MUST BE AT THE END */
        }

(note that the trailing comma is deliberately omitted).

It would allow people to say

        for (i = 0; i < ATOM_MAX; i++)

instead, which would be even nicer.

I think ATOM_INVALID and ATOM_MAX all will have a
similar effort. Why don't we omit one of them?

For the time being, all the used_atom entry create in
`parse_ref_filter_atom()`, we directly use
`used_atom[at].atom_type = i;` after realloc the used_atom.
There is no time for "ATOM_UNKNOWN" at all.

I don’t know if it makes a lot of sense use "ATOM_UNKNOWN"
at the moment.

--
ZheNing Hu