C++ wcstring::begin方法代码示例

void parser_t::get_backtrace(const wcstring &src, const parse_error_list_t &errors, wcstring *output) const
{
    assert(output != NULL);
    if (! errors.empty())
    {
        const parse_error_t &err = errors.at(0);

        const bool is_interactive = get_is_interactive();

        // Determine if we want to try to print a caret to point at the source error
        // The err.source_start <= src.size() check is due to the nasty way that slices work,
        // which is by rewriting the source (!)
        size_t which_line = 0;
        bool skip_caret = true;
        if (err.source_start != SOURCE_LOCATION_UNKNOWN && err.source_start <= src.size())
        {
            // Determine which line we're on
            which_line = 1 + std::count(src.begin(), src.begin() + err.source_start, L'\n');

            // Don't include the caret if we're interactive, this is the first line of text, and our source is at its beginning, because then it's obvious
            skip_caret = (is_interactive && which_line == 1 && err.source_start == 0);
        }

        wcstring prefix;
        const wchar_t *filename = this->current_filename();
        if (filename)
        {
            if (which_line > 0)
            {
                prefix = format_string(_(L"%ls (line %lu): "), user_presentable_path(filename).c_str(), which_line);
            }
            else
            {
                prefix = format_string(_(L"%ls: "), user_presentable_path(filename).c_str());
            }
        }
        else
        {
            prefix = L"fish: ";
        }

        const wcstring description = err.describe_with_prefix(src, prefix, is_interactive, skip_caret);
        if (! description.empty())
        {
            output->append(description);
            output->push_back(L'\n');
        }
        output->append(this->stack_trace());
    }
}

/**
   Attempts tilde expansion of the string specified, modifying it in place.
*/
static void expand_home_directory(wcstring &input)
{
    const wchar_t * const in = input.c_str();
    if (in[0] == HOME_DIRECTORY)
    {
        int tilde_error = 0;
        size_t tail_idx;
        wcstring home;

        if (in[1] == '/' || in[1] == '\0')
        {
            /* Current users home directory */

            home = env_get_string(L"HOME");
            tail_idx = 1;
        }
        else
        {
            /* Some other users home directory */
            const wchar_t *name_end = wcschr(in, L'/');
            if (name_end)
            {
                tail_idx = name_end - in;
            }
            else
            {
                tail_idx = wcslen(in);
            }
            wcstring name_str = input.substr(1, tail_idx - 1);
            std::string name_cstr = wcs2string(name_str);
            struct passwd *userinfo = getpwnam(name_cstr.c_str());

            if (userinfo == NULL)
            {
                tilde_error = 1;
                input[0] = L'~';
            }
            else
            {
                home = str2wcstring(userinfo->pw_dir);
            }
        }

        if (! tilde_error)
        {
            input.replace(input.begin(), input.begin() + tail_idx, home);
        }
    }
}

bool unescape_string(wcstring &str, int escape_special)
{
    bool success = false;
    wchar_t *result = unescape(str.c_str(), escape_special);
    if (result) {
        str.replace(str.begin(), str.end(), result);
        free(result);
        success = true;
    }
    return success;
}

/**
   Remove any internal separators. Also optionally convert wildcard characters to
   regular equivalents. This is done to support EXPAND_SKIP_WILDCARDS.
*/
static void remove_internal_separator(wcstring &str, bool conv)
{
    /* Remove all instances of INTERNAL_SEPARATOR */
    str.erase(std::remove(str.begin(), str.end(), (wchar_t)INTERNAL_SEPARATOR), str.end());

    /* If conv is true, replace all instances of ANY_CHAR with '?', ANY_STRING with '*', ANY_STRING_RECURSIVE with '*' */
    if (conv)
    {
        for (size_t idx = 0; idx < str.size(); idx++)
        {
            switch (str.at(idx))
            {
                case ANY_CHAR:
                    str.at(idx) = L'?';
                    break;
                case ANY_STRING:
                case ANY_STRING_RECURSIVE:
                    str.at(idx) = L'*';
                    break;
            }
        }
    }
}