Class Lexer

tools/ipc_codegen/ipc_codegen.cpp:124–216

};

class Lexer {
public:
    Lexer(std::string_view src, std::string filename)
        : src_(src), filename_(std::move(filename)) {}

    Token next() {
        skipWs();
        const int startLine = line_;
        const int startCol = column();
        if (pos_ >= src_.size()) return {Tok::End, "", startLine, startCol};

        const char c = src_[pos_];
        if (c == '{') { ++pos_; return {Tok::LBrace, "{", startLine, startCol}; }
        if (c == '}') { ++pos_; return {Tok::RBrace, "}", startLine, startCol}; }
        if (c == '(') { ++pos_; return {Tok::LParen, "(", startLine, startCol}; }
        if (c == ')') { ++pos_; return {Tok::RParen, ")", startLine, startCol}; }
        if (c == '[') { ++pos_; return {Tok::LBrack, "[", startLine, startCol}; }
        if (c == ']') { ++pos_; return {Tok::RBrack, "]", startLine, startCol}; }
        if (c == ',') { ++pos_; return {Tok::Comma, ",", startLine, startCol}; }
        if (c == ';') { ++pos_; return {Tok::Semi, ";", startLine, startCol}; }
        if (c == '=') { ++pos_; return {Tok::Equal, "=", startLine, startCol}; }
        if (c == ':' && pos_ + 1 < src_.size() && src_[pos_ + 1] == ':') {
            pos_ += 2;
            return {Tok::Scope, "::", startLine, startCol};
        }
        if (c == ':') { ++pos_; return {Tok::Colon, ":", startLine, startCol}; }

        if (std::isalpha(static_cast<unsigned char>(c)) || c == '_') {
            const size_t start = pos_++;
            while (pos_ < src_.size()) {
                const char next = src_[pos_];
                if (!std::isalnum(static_cast<unsigned char>(next)) && next != '_') break;
                ++pos_;
            }
            return {Tok::Ident, std::string(src_.substr(start, pos_ - start)), startLine, startCol};
        }

        if (std::isdigit(static_cast<unsigned char>(c))) {
            const size_t start = pos_++;
            while (pos_ < src_.size() &&
                   std::isalnum(static_cast<unsigned char>(src_[pos_]))) {
                ++pos_;
            }
            return {Tok::Int, std::string(src_.substr(start, pos_ - start)), startLine, startCol};
        }

        die(startLine, startCol, "unexpected character '" + std::string(1, c) + "'");
    }

    [[noreturn]] void die(int line, int col, const std::string& message) const {
        std::fprintf(stderr, "%s:%d:%d: error: %s\n",
                     filename_.c_str(), line, col, message.c_str());
        std::exit(1);
    }

private:
    void skipWs() {
        while (pos_ < src_.size()) {