sandbox/v1/parser.cc

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#include "defs.h"
#include "parser.h"
#include "stack.h"
#include <ctype.h>
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#include <string.h>
static inline void
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reset(struct Token *t)
{
t->token = nullptr;
t->length = 0;
}
bool
match_token(const char *a, const size_t alen,
const char *b, const size_t blen)
{
if (alen != blen) {
return false;
}
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for (size_t i = 0; i < alen; i++) {
if (a[i] == b[i]) {
continue;
}
if (!isalpha(a[i]) || !isalpha(b[i])) {
return false;
}
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if ((a[i] ^ 0x20) == b[i]) {
continue;
}
if (a[i] == (b[i] ^ 0x20)) {
continue;
}
return false;
}
return true;
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}
PARSE_RESULT
parse_next(const char *buf, const size_t length, size_t *offset,
struct Token *token)
{
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size_t cursor = *offset;
reset(token);
if (cursor == length) {
return PARSE_EOB;
}
while (cursor <= length) {
if (buf[cursor] != ' ') {
if (buf[cursor] != '\t') {
break;
}
}
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cursor++;
}
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if (cursor == length) {
return PARSE_EOB;
}
token->token = (char *)buf + cursor;
while ((token->length <= MAX_TOKEN_LENGTH) && (cursor < length)) {
if (buf[cursor] != ' ') {
if (buf[cursor] != '\t') {
cursor++;
token->length++;
continue;
}
}
cursor++;
break;
}
if (token->length > MAX_TOKEN_LENGTH) {
reset(token);
return PARSE_LEN;
}
*offset = cursor;
return PARSE_OK;
}
bool
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parse_num(struct Token *token, KF_INT *n)
{
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KF_INT tmp = 0;
uint8_t i = 0;
bool sign = false;
if (token->length == 0) {
return false;
}
if (token->token[i] == '-') {
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if (token->length == 1) {
return false;
}
i++;
sign = true;
}
while (i < token->length) {
if (token->token[i] < '0') {
return false;
}
if (token->token[i] > '9') {
return false;
}
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tmp *= 10;
tmp += (uint8_t)(token->token[i] - '0');
i++;
}
if (sign) {
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tmp *= -1;
}
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*n = tmp;
return true;
}