Function FormatString

library/cpp/yt/string/format-inl.h:421–508

template <class TStringBuilder>
void FormatString(TStringBuilder* builder, TStringBuf value, TStringBuf spec)
{
    if (!spec) {
        builder->AppendString(value);
        return;
    }

    // Parse alignment.
    bool alignLeft = false;
    const char* current = spec.begin();
    if (*current == '-') {
        alignLeft = true;
        ++current;
    }

    bool hasAlign = false;
    int alignSize = 0;
    while (*current >= '0' && *current <= '9') {
        hasAlign = true;
        alignSize = 10 * alignSize + (*current - '0');
        if (alignSize > 1000000) {
            builder->AppendString(TStringBuf("<alignment overflow>"));
            return;
        }
        ++current;
    }

    int padding = 0;
    bool padLeft = false;
    bool padRight = false;
    if (hasAlign) {
        padding = alignSize - value.size();
        if (padding < 0) {
            padding = 0;
        }
        padLeft = !alignLeft;
        padRight = alignLeft;
    }

    bool singleQuotes = false;
    bool doubleQuotes = false;
    bool escape = false;
    while (current < spec.end()) {
        switch (*current++) {
            case 'q':
                singleQuotes = true;
                break;
            case 'Q':
                doubleQuotes = true;
                break;
            case 'h':
                escape =  true;
                break;
        }
    }

    if (padLeft) {
        builder->AppendChar(' ', padding);