lexer_skip_spaces (parser_context_t *context_p) /**< context */
{
  skip_mode_t mode = LEXER_SKIP_SPACES;
  const uint8_t *source_end_p = context_p->source_end_p;

  if (context_p->token.flags & LEXER_NO_SKIP_SPACES)
  {
    context_p->token.flags &= (uint8_t) ~LEXER_NO_SKIP_SPACES;
    return;
  }

  context_p->token.flags = 0;

  while (true)
  {
    if (context_p->source_p >= source_end_p)
    {
      if (mode == LEXER_SKIP_MULTI_LINE_COMMENT)
      {
        parser_raise_error (context_p, PARSER_ERR_UNTERMINATED_MULTILINE_COMMENT);
      }
      return;
    }

    switch (context_p->source_p[0])
    {
      case LIT_CHAR_CR:
      {
        if (context_p->source_p + 1 < source_end_p && context_p->source_p[1] == LIT_CHAR_LF)
        {
          context_p->source_p++;
        }
        /* FALLTHRU */
      }

      case LIT_CHAR_LF:
      {
        context_p->line++;
        context_p->column = 0;
        context_p->token.flags = LEXER_WAS_NEWLINE;

        if (mode == LEXER_SKIP_SINGLE_LINE_COMMENT)
        {
          mode = LEXER_SKIP_SPACES;
        }
        /* FALLTHRU */
      }

      case LIT_CHAR_VTAB:
      case LIT_CHAR_FF:
      case LIT_CHAR_SP:
      {
        context_p->source_p++;
        context_p->column++;
        continue;
      }

      case LIT_CHAR_TAB:
      {
        context_p->column = align_column_to_tab (context_p->column);
        context_p->source_p++;
        continue;
      }

      case LIT_CHAR_SLASH:
      {
        if (mode == LEXER_SKIP_SPACES && context_p->source_p + 1 < source_end_p)
        {
          if (context_p->source_p[1] == LIT_CHAR_SLASH)
          {
            mode = LEXER_SKIP_SINGLE_LINE_COMMENT;
          }
          else if (context_p->source_p[1] == LIT_CHAR_ASTERISK)
          {
            mode = LEXER_SKIP_MULTI_LINE_COMMENT;
            context_p->token.line = context_p->line;
            context_p->token.column = context_p->column;
          }

          if (mode != LEXER_SKIP_SPACES)
          {
            context_p->source_p += 2;
            PARSER_PLUS_EQUAL_LC (context_p->column, 2);
            continue;
          }
        }
        break;
      }

      case LIT_CHAR_ASTERISK:
      {
        if (mode == LEXER_SKIP_MULTI_LINE_COMMENT && context_p->source_p + 1 < source_end_p
            && context_p->source_p[1] == LIT_CHAR_SLASH)
        {
          mode = LEXER_SKIP_SPACES;
          context_p->source_p += 2;
          PARSER_PLUS_EQUAL_LC (context_p->column, 2);
          continue;
        }
        break;
      }

      case 0xc2:
      {
        if (context_p->source_p + 1 < source_end_p && context_p->source_p[1] == 0xa0)
        {
          /* Codepoint \u00A0 */
          context_p->source_p += 2;
          context_p->column++;
          continue;
        }
        break;
      }

      case LEXER_NEWLINE_LS_PS_BYTE_1:
      {
        JERRY_ASSERT (context_p->source_p + 2 < source_end_p);
        if (LEXER_NEWLINE_LS_PS_BYTE_23 (context_p->source_p))
        {
          /* Codepoint \u2028 and \u2029 */
          context_p->source_p += 3;
          context_p->line++;
          context_p->column = 1;
          context_p->token.flags = LEXER_WAS_NEWLINE;

          if (mode == LEXER_SKIP_SINGLE_LINE_COMMENT)
          {
            mode = LEXER_SKIP_SPACES;
          }
          continue;
        }
        break;
      }

      case 0xef:
      {
        if (context_p->source_p + 2 < source_end_p && context_p->source_p[1] == 0xbb && context_p->source_p[2] == 0xbf)
        {
          /* Codepoint \uFEFF */
          context_p->source_p += 3;
          context_p->column++;
          continue;
        }
        break;
      }

      default:
      {
        break;
      }
    }

    if (mode == LEXER_SKIP_SPACES)
    {
      return;
    }

    context_p->source_p++;

    if (context_p->source_p < source_end_p && !IS_UTF8_INTERMEDIATE_OCTET (context_p->source_p[0]))
    {
      context_p->column++;
    }
  }
} /* lexer_skip_spaces */