Clean up main parser loop
This commit is contained in:
Max Brunsfeld
parent
5febda183a
commit
3ee58461d7
1 changed files with 86 additions and 103 deletions
|
|
@ -293,102 +293,96 @@ static TSTree *ts_parser__finish(TSParser *parser) {
|
|||
}
|
||||
|
||||
typedef enum {
|
||||
ParserNextResultNone,
|
||||
ParserNextResultAdvanced,
|
||||
ParserNextResultRemoved,
|
||||
ParserNextResultFinished
|
||||
} ParserNextResult;
|
||||
ConsumeResultShifted,
|
||||
ConsumeResultRemoved,
|
||||
ConsumeResultFinished
|
||||
} ConsumeResult;
|
||||
|
||||
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);
|
||||
/*
|
||||
* Continue performing parse actions for the given head until the current
|
||||
* lookahead symbol is consumed.
|
||||
*/
|
||||
static ConsumeResult ts_parser__consume_lookahead(TSParser *parser, int head) {
|
||||
for (;;) {
|
||||
TSStateId state = ts_stack_top_state(parser->stack, head);
|
||||
const TSParseAction *next_action =
|
||||
ts_language__actions(parser->language, state, parser->lookahead->symbol);
|
||||
|
||||
/*
|
||||
* 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++;
|
||||
/*
|
||||
* 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.
|
||||
*/
|
||||
while (next_action->type != 0) {
|
||||
TSParseAction action = *next_action;
|
||||
next_action++;
|
||||
|
||||
int head;
|
||||
if (next_action->type == 0) {
|
||||
head = head_to_advance;
|
||||
} else {
|
||||
head = ts_stack_split(parser->stack, head_to_advance);
|
||||
DEBUG("split from_head:%d", head_to_advance);
|
||||
}
|
||||
int current_head;
|
||||
if (next_action->type == 0) {
|
||||
current_head = head;
|
||||
DEBUG("action current_head:%d, state:%d", current_head, state);
|
||||
} else {
|
||||
current_head = ts_stack_split(parser->stack, head);
|
||||
DEBUG("split_action from_head:%d, current_head:%d, state:%d", head,
|
||||
current_head, state);
|
||||
}
|
||||
|
||||
DEBUG("action state:%d, head:%d", state, head);
|
||||
// TODO: Remove this by making a separate symbol for errors returned from
|
||||
// the lexer.
|
||||
if (parser->lookahead->symbol == ts_builtin_sym_error)
|
||||
action.type = TSParseActionTypeError;
|
||||
|
||||
// TODO: Remove this by making a separate symbol for errors returned from
|
||||
// the lexer.
|
||||
if (parser->lookahead->symbol == ts_builtin_sym_error)
|
||||
action.type = TSParseActionTypeError;
|
||||
switch (action.type) {
|
||||
case TSParseActionTypeError:
|
||||
DEBUG("error_sym");
|
||||
if (ts_stack_head_count(parser->stack) == 1) {
|
||||
if (ts_parser__handle_error(parser, current_head))
|
||||
break;
|
||||
else
|
||||
return ConsumeResultFinished;
|
||||
} else {
|
||||
DEBUG("bail current_head:%d", current_head);
|
||||
ts_stack_remove_head(parser->stack, current_head);
|
||||
return ConsumeResultRemoved;
|
||||
}
|
||||
|
||||
switch (action.type) {
|
||||
case TSParseActionTypeError:
|
||||
DEBUG("error_sym");
|
||||
if (ts_stack_head_count(parser->stack) == 1) {
|
||||
if (ts_parser__handle_error(parser, head))
|
||||
result = ParserNextResultNone;
|
||||
else
|
||||
result = ParserNextResultFinished;
|
||||
} else {
|
||||
DEBUG("bail head:%d", head);
|
||||
ts_stack_remove_head(parser->stack, head);
|
||||
result = ParserNextResultRemoved;
|
||||
}
|
||||
break;
|
||||
case TSParseActionTypeShift:
|
||||
DEBUG("shift state:%u", action.data.to_state);
|
||||
ts_parser__shift(parser, current_head, action.data.to_state);
|
||||
return ConsumeResultShifted;
|
||||
|
||||
case TSParseActionTypeShift:
|
||||
DEBUG("shift state:%u", action.data.to_state);
|
||||
ts_parser__shift(parser, head, action.data.to_state);
|
||||
result = ParserNextResultAdvanced;
|
||||
break;
|
||||
case TSParseActionTypeShiftExtra:
|
||||
DEBUG("shift_extra");
|
||||
ts_parser__shift_extra(parser, current_head, state);
|
||||
return ConsumeResultShifted;
|
||||
|
||||
case TSParseActionTypeShiftExtra:
|
||||
DEBUG("shift_extra");
|
||||
ts_parser__shift_extra(parser, head, state);
|
||||
result = ParserNextResultAdvanced;
|
||||
break;
|
||||
case TSParseActionTypeReduce:
|
||||
DEBUG("reduce sym:%s, child_count:%u", SYM_NAME(action.data.symbol),
|
||||
action.data.child_count);
|
||||
ts_parser__reduce(parser, current_head, action.data.symbol,
|
||||
action.data.child_count, false, false);
|
||||
break;
|
||||
|
||||
case TSParseActionTypeReduce:
|
||||
DEBUG("reduce sym:%s, child_count:%u", SYM_NAME(action.data.symbol),
|
||||
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, current_head, action.data.symbol, 1, true,
|
||||
false);
|
||||
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:
|
||||
DEBUG("reduce_fragile sym:%s, count:%u", SYM_NAME(action.data.symbol),
|
||||
action.data.child_count);
|
||||
ts_parser__reduce_fragile(parser, current_head, action.data.symbol,
|
||||
action.data.child_count);
|
||||
break;
|
||||
|
||||
case TSParseActionTypeReduceFragile:
|
||||
DEBUG("reduce_fragile sym:%s, count:%u", SYM_NAME(action.data.symbol),
|
||||
action.data.child_count);
|
||||
ts_parser__reduce_fragile(parser, head, action.data.symbol,
|
||||
action.data.child_count);
|
||||
result = ParserNextResultNone;
|
||||
break;
|
||||
|
||||
case TSParseActionTypeAccept:
|
||||
DEBUG("accept");
|
||||
result = ParserNextResultFinished;
|
||||
break;
|
||||
case TSParseActionTypeAccept:
|
||||
DEBUG("accept");
|
||||
return ConsumeResultFinished;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
static TSTree *ts_parser__select_tree(void *data, TSTree *left, TSTree *right) {
|
||||
|
|
@ -434,27 +428,16 @@ TSTree *ts_parser_parse(TSParser *parser, TSInput input, TSTree *previous_tree)
|
|||
parser->lexer.current_position.chars,
|
||||
ts_stack_head_count(parser->stack));
|
||||
|
||||
int head = 0;
|
||||
while (head < ts_stack_head_count(parser->stack)) {
|
||||
bool removed = false, advanced = false;
|
||||
|
||||
while (!(advanced || removed)) {
|
||||
switch (ts_parser__next(parser, head)) {
|
||||
case ParserNextResultNone:
|
||||
break;
|
||||
case ParserNextResultRemoved:
|
||||
removed = true;
|
||||
break;
|
||||
case ParserNextResultAdvanced:
|
||||
advanced = true;
|
||||
break;
|
||||
case ParserNextResultFinished:
|
||||
return ts_parser__finish(parser);
|
||||
}
|
||||
for (int head = 0; head < ts_stack_head_count(parser->stack);) {
|
||||
switch (ts_parser__consume_lookahead(parser, head)) {
|
||||
case ConsumeResultRemoved:
|
||||
break;
|
||||
case ConsumeResultShifted:
|
||||
head++;
|
||||
break;
|
||||
case ConsumeResultFinished:
|
||||
return ts_parser__finish(parser);
|
||||
}
|
||||
|
||||
if (!removed)
|
||||
head++;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue