C++ wcstring::erase方法代码示例

/**
   Remove any prefix and suffix newlines from the specified
   string.
 */
static void trim(wcstring &str)
{
    if (str.empty())
        return;

    size_t pos = str.find_first_not_of(L" \n");
    if (pos > 0)
        str.erase(0, pos);

    pos = str.find_last_not_of(L" \n");
    if (pos != wcstring::npos && pos + 1 < str.length())
        str.erase(pos + 1);
}

bool autosuggest_suggest_special(const wcstring &str, const wcstring &working_directory, wcstring &outSuggestion) {
    if (str.empty())
        return false;
        
    ASSERT_IS_BACKGROUND_THREAD();
    
    /* Parse the string */
    wcstring parsed_command;
    wcstring_list_t parsed_arguments;
    int parsed_last_arg_pos = -1;
    if (! autosuggest_parse_command(str, &parsed_command, &parsed_arguments, &parsed_last_arg_pos))
        return false;
    
    bool result = false;
    if (parsed_command == L"cd" && ! parsed_arguments.empty()) {        
        /* We can possibly handle this specially */
        wcstring dir = parsed_arguments.back();
        wcstring suggested_path;
        
        /* We always return true because we recognized the command. This prevents us from falling back to dumber algorithms; for example we won't suggest a non-directory for the cd command. */
        result = true;
        outSuggestion.clear();

        if (is_potential_cd_path(dir, working_directory, &suggested_path)) {
            /* Success */
            outSuggestion = str;
            outSuggestion.erase(parsed_last_arg_pos);
            outSuggestion.append(suggested_path);
        }
    } else {
        /* Either an error or some other command, so we don't handle it specially */
    }
    return result;
}

/* We have to return an escaped string here */
bool autosuggest_suggest_special(const wcstring &str, const wcstring &working_directory, wcstring &outSuggestion) {
    if (str.empty())
        return false;
        
    ASSERT_IS_BACKGROUND_THREAD();
    
    /* Parse the string */
    wcstring parsed_command;
    wcstring_list_t parsed_arguments;
    int parsed_last_arg_pos = -1;
    if (! autosuggest_parse_command(str, &parsed_command, &parsed_arguments, &parsed_last_arg_pos))
        return false;
    
    bool result = false;
    if (parsed_command == L"cd" && ! parsed_arguments.empty()) {        
        /* We can possibly handle this specially */
        const wcstring escaped_dir = parsed_arguments.back();
        wcstring suggested_path;
        
        /* We always return true because we recognized the command. This prevents us from falling back to dumber algorithms; for example we won't suggest a non-directory for the cd command. */
        result = true;
        outSuggestion.clear();
        
        /* Unescape the parameter */
        wcstring unescaped_dir = escaped_dir;
        bool unescaped = unescape_string(unescaped_dir, UNESCAPE_INCOMPLETE);
        
        /* Determine the quote type we got from the input directory. */
        wchar_t quote = L'\0';
        parse_util_get_parameter_info(escaped_dir, 0, &quote, NULL, NULL);
        
        /* Big hack to avoid expanding a tilde inside quotes */
        path_flags_t path_flags = (quote == L'\0') ? PATH_EXPAND_TILDE : 0;
        if (unescaped && is_potential_cd_path(unescaped_dir, working_directory, path_flags, &suggested_path)) {
                    
            /* Note: this looks really wrong for strings that have an "unescapable" character in them, e.g. a \t, because parse_util_escape_string_with_quote will insert that character */
            wcstring escaped_suggested_path = parse_util_escape_string_with_quote(suggested_path, quote);

            /* Return it */
            outSuggestion = str;
            outSuggestion.erase(parsed_last_arg_pos);
            if (quote != L'\0') outSuggestion.push_back(quote);
            outSuggestion.append(escaped_suggested_path);
            if (quote != L'\0') outSuggestion.push_back(quote);
        }
    } else {
        /* Either an error or some other command, so we don't handle it specially */
    }
    return result;
}

void append_path_component(wcstring &path, const wcstring &component)
{
    if (path.empty() || component.empty()) {
        path.append(component);
    } else {
        size_t path_len = path.size();
        bool path_slash = path.at(path_len-1) == L'/';
        bool comp_slash = component.at(0) == L'/';
        if (! path_slash && ! comp_slash) {
            // Need a slash
            path.push_back(L'/');
        } else if (path_slash && comp_slash) {
            // Too many slashes
            path.erase(path_len - 1, 1);
        }
        path.append(component);
    }
}

/**
   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;
            }
        }
    }
}