Eric Blake <ebl...@redhat.com> writes:
> On 08/27/2018 02:00 AM, Markus Armbruster wrote:
>> The lexer ignores whitespace like this:
>>
>> on whitespace on non-ws spontaneously
>> IN_START --> IN_WHITESPACE --> JSON_SKIP --> IN_START
>> ^ |
>> \__/ on whitespace
>>
>> This accumulates a whitespace token in state IN_WHITESPACE, only to
>> throw it away on the transition via JSON_SKIP to the start state.
>> Wasteful. Go from IN_START to IN_START on whitspace directly,
>
> s/whitspace/whitespace/
Will fix.
>> dropping the whitespace character.
>>
>> Signed-off-by: Markus Armbruster <arm...@redhat.com>
>> ---
>> qobject/json-lexer.c | 22 +++++-----------------
>> qobject/json-parser-int.h | 1 -
>> 2 files changed, 5 insertions(+), 18 deletions(-)
>>
>> @@ -263,10 +253,10 @@ static const uint8_t json_lexer[][256] = {
>> [','] = JSON_COMMA,
>> [':'] = JSON_COLON,
>> ['a' ... 'z'] = IN_KEYWORD,
>> - [' '] = IN_WHITESPACE,
>> - ['\t'] = IN_WHITESPACE,
>> - ['\r'] = IN_WHITESPACE,
>> - ['\n'] = IN_WHITESPACE,
>> + [' '] = IN_START,
>> + ['\t'] = IN_START,
>> + ['\r'] = IN_START,
>> + ['\n'] = IN_START,
>> },
>> [IN_START_INTERP]['%'] = IN_INTERP,
>
> Don't you need to set [IN_START_INTERP][' '] to IN_START_INTERP,
> rather than IN_START? Otherwise, the presence of skipped whitespace
> would change whether interpolation happens. (At least, that's what
> you had in an earlier version of this patch).
>
>> };
>> @@ -323,10 +313,8 @@ static void json_lexer_feed_char(JSONLexer *lexer, char
>> ch, bool flush)
>> json_message_process_token(lexer, lexer->token, new_state,
>> lexer->x, lexer->y);
>> /* fall through */
>> - case JSON_SKIP:
>> - g_string_truncate(lexer->token, 0);
>> - /* fall through */
>> case IN_START:
>> + g_string_truncate(lexer->token, 0);
>> new_state = lexer->start_state;
>
> Oh, I see. We are magically reverting to the correct start state if
> the requested transition reports IN_START, rather than blindly using
> IN_START.
Correct. Less repetitive this way.
> Reviewed-by: Eric Blake <ebl...@redhat.com>
Thanks!
