Re: [Qemu-devel] [PATCH 5/6] json: Eliminate lexer state IN_ERROR

[Markus Armbruster <armbru@redhat.com>]

Eric Blake <eblake@redhat.com> writes:

> On 08/27/2018 02:00 AM, Markus Armbruster wrote:
>> Signed-off-by: Markus Armbruster <armbru@redhat.com>
>> ---
>>   qobject/json-lexer.c      | 9 +++++----
>>   qobject/json-parser-int.h | 8 ++++----
>>   2 files changed, 9 insertions(+), 8 deletions(-)
>
>> -
>>   typedef enum json_token_type {
>> -    JSON_MIN = 100,
>> -    JSON_LCURLY = JSON_MIN,
>> +    JSON_ERROR = 0,             /* must be zero, see json_lexer[] */
>> +    /* Gap for lexer states */
>> +    JSON_LCURLY = 100,
>> +    JSON_MIN = JSON_LCURLY,
>
> In an earlier version of this type of cleanup, you swapped the IN_ and
> JSON_ values and eliminated the gap, to make the overall table more
> compact (no storage wasted on any of the states in the gap between the
> two).
>
> https://lists.gnu.org/archive/html/qemu-devel/2018-08/msg01178.html
>
> Is it still worth trying to minimize the gap between the two
> sequences, even if you now no longer swap them in order?

You caught me :)

Eliminating the gap actually enlarges the table.  I first got confused,
then measured the size change backwards to confirm my confused ideas.
When I looked at the patch again, I realized my mistake, and silently
dropped this part of the change.