traxys/tree-sitter
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Clean up and document ts_parser__next function

Browse source
This commit is contained in:
Max Brunsfeld 2015-10-06 11:43:34 -07:00
parent 624e4651d2
commit 85466a5b22
1 changed files with 19 additions and 6 deletions
Download patch file Download diff file Expand all files Collapse all files

25
src/runtime/parser.c
View file

@ -289,11 +289,19 @@ typedef enum {
} ParserNextResult;
static ParserNextResult ts_parser__next(TSParser *parser, int head_to_advance) {
ParserNextResult result = ParserNextResultNone;
TSStateId state = ts_stack_top_state(parser->stack, head_to_advance);
const TSParseAction *next_action =
ts_language__actions(parser->language, state, parser->lookahead->symbol);
ParserNextResult result = ParserNextResultNone;
/*
* If there are multiple actions for the current state and lookahead symbol,
* split the stack so that each one can be performed. If there is a `SHIFT`
* action, it will always appear *last* in the list of actions. Perform it
* on the original stack head, and return `ParserNextResultAdvanced`, to
* indicate that the original head has finished consuming this lookahead
* symbol.
*/
while (next_action->type != 0) {
TSParseAction action = *next_action;
next_action++;
@ -303,7 +311,7 @@ static ParserNextResult ts_parser__next(TSParser *parser, int head_to_advance) {
head = head_to_advance;
} else {
head = ts_stack_split(parser->stack, head_to_advance);
DEBUG("split from_head:%d, to_head:%d", head_to_advance, head);
DEBUG("split from_head:%d", head_to_advance);
}
DEBUG("action state:%d, head:%d", state, head);
@ -318,14 +326,15 @@ static ParserNextResult ts_parser__next(TSParser *parser, int head_to_advance) {
DEBUG("error_sym");
if (ts_stack_head_count(parser->stack) == 1) {
if (ts_parser__handle_error(parser, head))
break;
result = ParserNextResultNone;
else
return ParserNextResultFinished;
result = ParserNextResultFinished;
} else {
DEBUG("bail head:%d", head);
ts_stack_remove_head(parser->stack, head);
return ParserNextResultRemoved;
result = ParserNextResultRemoved;
}
break;
case TSParseActionTypeShift:
DEBUG("shift state:%u", action.data.to_state);
@ -344,11 +353,13 @@ static ParserNextResult ts_parser__next(TSParser *parser, int head_to_advance) {
action.data.child_count);
ts_parser__reduce(parser, head, action.data.symbol,
action.data.child_count, false, false);
result = ParserNextResultNone;
break;
case TSParseActionTypeReduceExtra:
DEBUG("reduce_extra sym:%s", SYM_NAME(action.data.symbol));
ts_parser__reduce(parser, head, action.data.symbol, 1, true, false);
result = ParserNextResultNone;
break;
case TSParseActionTypeReduceFragile:
@ -356,11 +367,13 @@ static ParserNextResult ts_parser__next(TSParser *parser, int head_to_advance) {
action.data.child_count);
ts_parser__reduce_fragile(parser, head, action.data.symbol,
action.data.child_count);
result = ParserNextResultNone;
break;
case TSParseActionTypeAccept:
DEBUG("accept");
return ParserNextResultFinished;
result = ParserNextResultFinished;
break;
}
}