str.c

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "str.h"

JsonValue *match_string(char *json, int *index, int size)
{
  JsonValue *result = create_json_value();
  result->start = *index;
  result->end = *index;
  result->type = JSON_STRING;
  result->error->code = "";

  // should start with a double quote
  if (json[*index] != '"')
  {
    result->error->code = "string-no-opening-quote";
    return result;
  }

  result->partial = 1;

  int forbidden_len = strlen(FORBIDDEN);
  int forbidden_chars_len = strlen(FORBIDDEN_CHARS);
  int stop = 0;
  int i = 0;
  int j = 0;
  char ch = '\0';

  while (result->end < size)
  {
    result->end++;

    ch = json[result->end];

    for (i = 0; i < forbidden_len; i++)
    {
      if (ch == FORBIDDEN[i])
      {
        if (ch == '\\')
        {
          // should match escape character
          for (j = 0; j < forbidden_chars_len; j++)
          {
            if (json[result->end + 1] == FORBIDDEN_CHARS[j])
            {
              // escaped successfully
              result->end++;
              break;
            }
          }
        }
        else if (ch == '"')
        {
          stop = 1;
          free_json_error(result->error);
          result->error = NULL;
          break;
        }
        else
        {
          result->error->code = "string-no-unescaped-forbidden-char";
          result->error->index = result->end;
          stop = 1;
        }

        break;
      }
    }

    if (stop == 1)
    {
      break;
    }
  }

  // last character should be a double quote
  if (json[result->end] != '"' && strcmp(result->error->code, "") == 0)
  {
    if (result->error != NULL)
    {
      result->error = create_json_error(result->end, "string-no-closing-quote");
    }
    else
    {
      result->error->code = "string-no-closing-quote";
    }
  }

  if (result->error == NULL)
  {
    // copy the value of the string from start to end in a new string
    result->string = slice_string(json, result->start + 1, result->end);
  }

  return result;
}