Function Wrap

library/cpp/getopt/small/wrap.cpp:12–98

namespace NLastGetopt {
    TString Wrap(ui32 width, TStringBuf text, TStringBuf indent, size_t* lastLineLen, bool* hasParagraphs) {
        if (width == 0) {
            return TString(text);
        }

        if (width >= indent.size()) {
            width -= indent.size();
        }

        if (hasParagraphs) {
            *hasParagraphs = false;
        }

        TString res;
        auto os = TStringOutput(res);

        const char* spaceBegin = text.begin();
        const char* wordBegin = text.begin();
        const char* wordEnd = text.begin();
        const char* end = text.end();

        size_t lenSoFar = 0;

        bool isPreParagraph = false;

        do {
            spaceBegin = wordBegin = wordEnd;

            while (wordBegin < end && *wordBegin == ' ') {
                wordBegin++;
            }

            if (wordBegin == end) {
                break;
            }

            wordEnd = wordBegin;

            while (wordEnd < end && *wordEnd != ' ' && *wordEnd != '\n') {
                wordEnd++;
            }

            auto spaces = TStringBuf(spaceBegin, wordBegin);
            auto word = TStringBuf(wordBegin, wordEnd);

            size_t spaceLen = spaces.size();

            size_t wordLen = 0;
            if (!GetNumberOfUTF8Chars(word.data(), word.size(), wordLen)) {
                wordLen = word.size(); // not a utf8 string -- just use its binary size
            }
            wordLen -= NColorizer::TotalAnsiEscapeCodeLen(word);

            // Empty word means we've found a bunch of whitespaces followed by newline.
            // We don't want to print trailing whitespaces.
            if (word) {
                // We can't fit this word into the line -- insert additional line break.
                // We shouldn't insert line breaks if we're at the beginning of a line, hence `lenSoFar` check.