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/
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.
Reviewed-by: Eric Blake <ebl...@redhat.com>
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org
