libabacus/src/parser.c

82 lines
2.4 KiB
C

#include "libabacus.h"
#include "parser.h"
#include "libabacus_util.h"
#include "lexer.h"
#include <stdlib.h>
struct parser_state {
ll_node* current_node;
lexer_match* current_match;
const char* string;
};
void _parser_state_update(struct parser_state* state) {
state->current_match = state->current_node ? state->current_node->data : NULL;
}
void _parser_state_init(struct parser_state* state, ll* tokens, const char* string) {
state->current_node = tokens->head;
state->string = string;
_parser_state_update(state);
}
void _parser_state_step(struct parser_state* state) {
if(state->current_node) {
state->current_node = state->current_node->next;
}
_parser_state_update(state);
}
int _parser_is_char(struct parser_state* state, char to_expect) {
return (state->current_match && state->current_match->type == TOKEN_CHAR &&
state->string[state->current_match->from] == to_expect);
}
int _parser_eof(struct parser_state* state) {
return state->current_match == NULL;
}
libab_result _parser_consume_char(struct parser_state* state, char to_consume) {
libab_result result = LIBAB_SUCCESS;
if(state->current_match == NULL) {
result = LIBAB_EOF;
} else if(state->current_match->type != TOKEN_CHAR ||
state->string[state->current_match->from] != to_consume) {
result = LIBAB_UNEXPECTED;
} else {
_parser_state_step(state);
}
return result;
}
libab_result _parse_block(struct parser_state* state,
tree** store_into, int expect_braces) {
libab_result result = LIBAB_SUCCESS;
*store_into = malloc(sizeof(**store_into));
if(*store_into == NULL) result = LIBAB_MALLOC;
if(expect_braces && result == LIBAB_SUCCESS) result = _parser_consume_char(state, '{');
while(result == LIBAB_SUCCESS &&
!_parser_eof(state) &&
!(expect_braces && _parser_is_char(state, '}'))) {
}
if(expect_braces && result == LIBAB_SUCCESS) result = _parser_consume_char(state, '}');
return result;
}
libab_result parse_tokens(ll* tokens, const char* string, tree** store_into) {
libab_result result = LIBAB_SUCCESS;
struct parser_state state;
_parser_state_init(&state, tokens, string);
result = _parse_block(&state, store_into, 0);
if(result == LIBAB_SUCCESS) {
(*store_into)->variant = BASE;
}
return result;
}