Function cpatterns_same 

pub fn cpatterns_same(a: Option<&Cpattern>, b: Option<&Cpattern>) -> bool

Port of cpatterns_same(Cpattern a, Cpattern b) from Src/Zle/compmatch.c:42.

static int
cpatterns_same(Cpattern a, Cpattern b)
{
    while (a) {
        if (!b) return 0;
        if (a->tp != b->tp) return 0;
        switch (a->tp) {
        case CPAT_CCLASS: case CPAT_NCLASS: case CPAT_EQUIV:
            if (strcmp(a->u.str, b->u.str) != 0) return 0;
            break;
        case CPAT_CHAR:
            if (a->u.chr != b->u.chr) return 0;
            break;
        default:
            break;
        }
        a = a->next;
        b = b->next;
    }
    return !b;
}

Walk two parallel Cpattern chains testing structural equality (same tp + same str for class types or same chr for CPAT_CHAR). Used by cmatchers_same to dedupe matcher specs. WARNING: param names don’t match C — Rust=(b) vs C=(a, b) cpatterns_same — see implementation.