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parse_hashtab.c
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parse_hashtab.c
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#include "util.h"
#include "parser.h"
static void
emit_hashtab(parser_t* parser) {
composite_state_t* top = pstack_top(parser);
ASSERT(top->obj.common.obj_ty == OT_HASHTAB);
obj_t* array_obj = &top->obj.common;
composite_state_t* new_top = pstack_pop(parser);
insert_subobj(&new_top->obj, array_obj);
}
typedef enum {
PKVP_DONE,
PKVP_COMPOSITE,
PKVP_CLOSE,
PKVP_ERR,
} PKVP_STATE;
static PKVP_STATE
parse_keyval_pair(parser_t* parser, obj_composite_t* htab_obj) {
scaner_t* scaner = &parser->scaner;
const char* json_end = scaner->json_end;
token_t* tk = sc_get_token(scaner, json_end);
/* step 1: Parse the key string */
if (tk->type == TT_STR) {
if (unlikely(!emit_primitive_tk(parser->mempool, tk, htab_obj))) {
return PKVP_ERR;
}
} else if (tk->type == TT_CHAR && tk->char_val == '}') {
return PKVP_CLOSE;
} else {
if (tk->type != TT_ERR) {
sc_rewind(scaner);
set_parser_err(parser, "Key must be a string");
}
return PKVP_ERR;
}
/* step 2: Expect ':' delimiter */
tk = sc_get_token(scaner, json_end);
if (tk->type != TT_CHAR || tk->char_val != ':') {
set_parser_err(parser, "expect ':'");
return PKVP_ERR;
}
/* step 3: parse the 'value' part */
tk = sc_get_token(scaner, json_end);
if (tk_is_primitive(tk)) {
if (unlikely(!emit_primitive_tk(parser->mempool, tk, htab_obj)))
return PKVP_ERR;
return PKVP_DONE;
}
if (tk->type == TT_CHAR) {
char c = tk->char_val;
if (c == '{') {
start_parsing_hashtab(parser);
return PKVP_COMPOSITE;
}
if (c == '[') {
start_parsing_array(parser);
return PKVP_COMPOSITE;
}
}
set_parser_err(parser, "value object syntax error");
return PKVP_ERR;
}
typedef enum {
PHT_JUST_BEGUN,
PHT_PARSING_ELMT,
} PHT_STATE;
int
parse_hashtab(parser_t* parser) {
scaner_t* scaner = &parser->scaner;
const char* json_end = scaner->json_end;
composite_state_t* state = pstack_top(parser);
PHT_STATE parse_state = state->parse_state;
if (parse_state == PHT_JUST_BEGUN) {
state->parse_state = PHT_PARSING_ELMT;
PKVP_STATE ret = parse_keyval_pair(parser, &state->obj);
switch (ret) {
case PKVP_DONE:
parse_state = PHT_PARSING_ELMT;
break;
case PKVP_COMPOSITE:
return 1;
case PKVP_CLOSE:
emit_hashtab(parser);
return 1;
default:
goto err_out;
}
}
while (1) {
token_t* tk = sc_get_token(scaner, json_end);
if (tk->type == TT_CHAR) {
char c = tk->char_val;
if (c == ',') {
PKVP_STATE ret = parse_keyval_pair(parser, &state->obj);
if (ret == PKVP_DONE)
continue;
else if (ret == PKVP_COMPOSITE) {
return 1;
}
goto err_out;
}
if (c == '}') {
emit_hashtab(parser);
return 1;
}
}
goto err_out;
}
err_out:
set_parser_err(parser, "hashtab syntax error");
return 0;
}
int
start_parsing_hashtab(parser_t* parser) {
if (!pstack_push(parser, OT_HASHTAB, PHT_JUST_BEGUN))
return 0;
return parse_hashtab(parser);
}