pocketpy/src/objects/sourcedata.cpp

#include "pocketpy/objects/sourcedata.hpp"

namespace pkpy {
SourceData::SourceData(std::string_view source, const Str& filename, CompileMode mode) :
    filename(filename), mode(mode) {
    int index = 0;
    // Skip utf8 BOM if there is any.
    if(strncmp(source.data(), "\xEF\xBB\xBF", 3) == 0) index += 3;
    // Drop all '\r'
    SStream ss(source.size() + 1);
    while(index < source.size()) {
        if(source[index] != '\r') ss << source[index];
        index++;
    }
    this->source = ss.str();
    if(this->source.size > 5 && this->source.sv().substr(0, 5) == "pkpy:") {
        this->is_precompiled = true;
    } else {
        this->is_precompiled = false;
    }
    line_starts.push_back(this->source.c_str());
}

SourceData::SourceData(const Str& filename, CompileMode mode) : filename(filename), mode(mode) {
    line_starts.push_back(this->source.c_str());
}

pair<const char*, const char*> SourceData::_get_line(int lineno) const {
    if(is_precompiled || lineno == -1) return {nullptr, nullptr};
    lineno -= 1;
    if(lineno < 0) lineno = 0;
    const char* _start = line_starts[lineno];
    const char* i = _start;
    // max 300 chars
    while(*i != '\n' && *i != '\0' && i - _start < 300)
        i++;
    return {_start, i};
}

std::string_view SourceData::get_line(int lineno) const {
    auto [_0, _1] = _get_line(lineno);
    if(_0 && _1) return std::string_view(_0, _1 - _0);
    return "<?>";
}

Str SourceData::snapshot(int lineno, const char* cursor, std::string_view name) const {
    SStream ss;
    ss << "  " << "File \"" << filename << "\", line " << lineno;
    if(!name.empty()) ss << ", in " << name;
    if(!is_precompiled) {
        ss << '\n';
        pair<const char*, const char*> pair = _get_line(lineno);
        Str line = "<?>";
        int removed_spaces = 0;
        if(pair.first && pair.second) {
            line = Str(pair.first, pair.second - pair.first).lstrip();
            removed_spaces = pair.second - pair.first - line.length();
            if(line.empty()) line = "<?>";
        }
        ss << "    " << line;
        if(cursor && line != "<?>" && cursor >= pair.first && cursor <= pair.second) {
            auto column = cursor - pair.first - removed_spaces;
            if(column >= 0) ss << "\n    " << std::string(column, ' ') << "^";
        }
    }
    return ss.str();
}
}  // namespace pkpy