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Clean up parser code

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This commit is contained in:
Max Brunsfeld 2014-10-08 16:49:52 -07:00
parent 5569a3ead9
commit 26f9e22193
1 changed files with 29 additions and 41 deletions
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70
src/runtime/parser.c
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@ -7,6 +7,10 @@
#include "runtime/parser.h"
#include "runtime/length.h"
/*
* Private
*/
#define DEBUG_PARSE(...) \
if (parser->debug) { \
fprintf(stderr, "PARSE " __VA_ARGS__); \
@ -18,6 +22,10 @@ static TSParseAction action_for(const TSLanguage *lang, TSStateId state,
return (lang->parse_table + (state * lang->symbol_count))[sym];
}
static void lex(TSParser *parser, TSStateId lex_state) {
parser->lookahead = parser->language->lex_fn(&parser->lexer, lex_state);
}
static TSLength breakdown_stack(TSParser *parser, TSInputEdit *edit) {
if (!edit) {
ts_stack_shrink(&parser->stack, 0);
@ -60,6 +68,13 @@ static TSLength breakdown_stack(TSParser *parser, TSInputEdit *edit) {
return position;
}
static void resize_error(TSParser *parser, TSTree *error) {
error->size =
ts_length_sub(ts_length_sub(parser->lexer.token_start_position,
ts_stack_right_position(&parser->stack)),
error->padding);
}
static void shift(TSParser *parser, TSStateId parse_state) {
if (ts_tree_is_extra(parser->lookahead))
parse_state = ts_stack_top_state(&parser->stack);
@ -100,35 +115,9 @@ static void reduce(TSParser *parser, TSSymbol symbol, size_t child_count) {
ts_stack_shrink(stack, stack->size - child_count);
}
static int reduce_extra(TSParser *parser, TSSymbol symbol) {
TSTree *last_node = NULL;
TS_STACK_FROM_TOP(parser->stack, entry) {
if (!ts_tree_is_extra(entry->node)) {
last_node = entry->node;
break;
}
}
if (last_node && last_node->symbol == symbol) {
reduce(parser, symbol, 1);
ts_tree_set_extra(parser->lookahead);
return 1;
} else {
return 0;
}
}
static void lex(TSParser *parser, TSStateId lex_state) {
if (parser->lookahead)
ts_tree_release(parser->lookahead);
parser->lookahead = parser->language->lex_fn(&parser->lexer, lex_state);
}
static void resize_error(TSParser *parser, TSTree *error) {
error->size =
ts_length_sub(ts_length_sub(parser->lexer.token_start_position,
ts_stack_right_position(&parser->stack)),
error->padding);
static void reduce_extra(TSParser *parser, TSSymbol symbol) {
reduce(parser, symbol, 1);
ts_tree_set_extra(parser->lookahead);
}
static int handle_error(TSParser *parser) {
@ -172,6 +161,8 @@ static int handle_error(TSParser *parser) {
*/
DEBUG_PARSE("LEX AGAIN");
TSLength prev_position = parser->lexer.current_position;
if (parser->lookahead)
ts_tree_release(parser->lookahead);
lex(parser, ts_lex_state_error);
/*
@ -201,12 +192,9 @@ static TSTree *get_root(TSParser *parser) {
return parser->stack.entries[0].node;
}
static TSParseAction next_action(TSParser *parser) {
TSStateId state = ts_stack_top_state(&parser->stack);
if (!parser->lookahead)
lex(parser, parser->language->lex_states[state]);
return action_for(parser->language, state, parser->lookahead->symbol);
}
/*
* Public
*/
TSParser ts_parser_make(const TSLanguage *language) {
return (TSParser) { .lexer = ts_lexer_make(),
@ -233,7 +221,11 @@ const TSTree *ts_parser_parse(TSParser *parser, TSInput input,
ts_lexer_reset(&parser->lexer, position);
for (;;) {
TSParseAction action = next_action(parser);
TSStateId state = ts_stack_top_state(&parser->stack);
if (!parser->lookahead)
lex(parser, parser->language->lex_states[state]);
TSParseAction action = action_for(parser->language, state, parser->lookahead->symbol);
DEBUG_PARSE("LOOKAHEAD %s",
parser->language->symbol_names[parser->lookahead->symbol]);
@ -261,12 +253,8 @@ const TSTree *ts_parser_parse(TSParser *parser, TSInput input,
break;
case TSParseActionTypeReduceExtra:
if (!reduce_extra(parser, action.data.symbol)) {
DEBUG_PARSE("ERROR");
if (!handle_error(parser))
return get_root(parser);
}
DEBUG_PARSE("REDUCE EXTRA");
reduce_extra(parser, action.data.symbol);
break;
case TSParseActionTypeAccept: