C++ parser::pos方法代码示例

static notation_entry parse_notation(parser & p, bool overload, notation_entry_group grp, buffer<token_entry> & new_tokens,
                                     bool allow_local) {
    bool parse_only   = false;
    unsigned priority = LEAN_DEFAULT_NOTATION_PRIORITY;
    flet<bool> set_allow_local(g_allow_local, allow_local);
    if (p.curr_is_token(get_infix_tk()) || p.curr_is_token(get_infixl_tk())) {
        p.next();
        return parse_mixfix_notation(p, mixfix_kind::infixl, overload, grp, new_tokens, parse_only, priority);
    } else if (p.curr_is_token(get_infixr_tk())) {
        p.next();
        return parse_mixfix_notation(p, mixfix_kind::infixr, overload, grp, new_tokens, parse_only, priority);
    } else if (p.curr_is_token(get_postfix_tk())) {
        p.next();
        return parse_mixfix_notation(p, mixfix_kind::postfix, overload, grp, new_tokens, parse_only, priority);
    } else if (p.curr_is_token(get_prefix_tk())) {
        p.next();
        return parse_mixfix_notation(p, mixfix_kind::prefix, overload, grp, new_tokens, parse_only, priority);
    } else if (p.curr_is_token(get_notation_tk())) {
        p.next();
        return parse_notation_core(p, overload, grp, new_tokens, parse_only, priority);
    } else {
        throw parser_error("invalid notation, 'infix', 'infixl', 'infixr', 'prefix', "
                           "'postfix' or 'notation' expected", p.pos());
    }
}

static transition parse_transition(parser & p, optional<parse_table> const & pt, name const & tk,
                                   buffer<expr> & locals, buffer<token_entry> & new_tokens, notation_entry_group grp,
                                   name const & pp_tk) {
    if (p.curr_is_token_or_id(get_binder_tk())) {
        p.next();
        unsigned rbp = parse_binders_rbp(p);
        return transition(tk, mk_binder_action(rbp), pp_tk);
    } else if (p.curr_is_token_or_id(get_binders_tk())) {
        p.next();
        unsigned rbp = parse_binders_rbp(p);
        return transition(tk, mk_binders_action(rbp), pp_tk);
    } else if (p.curr_is_identifier()) {
        unsigned default_prec = get_default_prec(pt, tk);
        name n   = p.get_name_val();
        p.next();
        action a = parse_action(p, tk, default_prec, locals, new_tokens, grp);
        expr local_type = mk_Prop(); // type used in notation local declarations, it is irrelevant
        expr l = mk_local(n, local_type);
        p.add_local(l);
        locals.push_back(l);
        return transition(tk, a, pp_tk);
    } else if (p.curr_is_quoted_symbol() || p.curr_is_keyword() ||
               p.curr_is_token(get_assign_tk()) || p.curr_is_command() || p.curr_is_eof()) {
        return transition(tk, mk_skip_action(), pp_tk);
    } else {
        throw parser_error("invalid notation declaration, quoted-symbol, identifier, "
                           "'binder', 'binders' expected", p.pos());
    }
}

// using [class] id (id ...) (renaming id->id id->id) (hiding id ... id)
environment using_cmd(parser & p) {
    environment env = p.env();
    while (true) {
        name cls = parse_class(p);
        bool decls = cls.is_anonymous() || cls == g_decls || cls == g_declarations;
        auto pos   = p.pos();
        name ns    = p.check_id_next("invalid 'using' command, identifier expected");
        optional<name> real_ns = to_valid_namespace_name(env, ns);
        if (!real_ns)
            throw parser_error(sstream() << "invalid namespace name '" << ns << "'", pos);
        ns = *real_ns;
        env = using_namespace(env, p.ios(), ns, cls);
        if (decls) {
            // Remark: we currently to not allow renaming and hiding of universe levels
            buffer<name> exceptions;
            bool found_explicit = false;
            while (p.curr_is_token(g_lparen)) {
                p.next();
                if (p.curr_is_token_or_id(g_renaming)) {
                    p.next();
                    while (p.curr_is_identifier()) {
                        name from_id = p.get_name_val();
                        p.next();
                        p.check_token_next(g_arrow, "invalid 'using' command renaming, '->' expected");
                        name to_id = p.check_id_next("invalid 'using' command renaming, identifier expected");
                        check_identifier(p, env, ns, from_id);
                        exceptions.push_back(from_id);
                        env = add_expr_alias(env, to_id, ns+from_id);
                    }
                } else if (p.curr_is_token_or_id(g_hiding)) {
                    p.next();
                    while (p.curr_is_identifier()) {
                        name id = p.get_name_val();
                        p.next();
                        check_identifier(p, env, ns, id);
                        exceptions.push_back(id);
                    }
                } else if (p.curr_is_identifier()) {
                    found_explicit = true;
                    while (p.curr_is_identifier()) {
                        name id = p.get_name_val();
                        p.next();
                        check_identifier(p, env, ns, id);
                        env = add_expr_alias(env, id, ns+id);
                    }
                } else {
                    throw parser_error("invalid 'using' command option, identifier, 'hiding' or 'renaming' expected", p.pos());
                }
                if (found_explicit && !exceptions.empty())
                    throw parser_error("invalid 'using' command option, mixing explicit and implicit 'using' options", p.pos());
                p.check_token_next(g_rparen, "invalid 'using' command option, ')' expected");
            }
            if (!found_explicit)
                env = add_aliases(env, ns, name(), exceptions.size(), exceptions.data());
        }
        if (!p.curr_is_token(g_lbracket) && !p.curr_is_identifier())
            break;
    }
    return env;
}

environment coercion_cmd(parser & p) {
    auto pos = p.pos();
    expr f   = p.parse_expr();
    if (!is_constant(f))
        throw parser_error("invalid 'coercion' command, constant expected", pos);
    if (p.curr_is_token(g_colon)) {
        p.next();
        pos = p.pos();
        expr C = p.parse_expr();
        if (!is_constant(C))
            throw parser_error("invalid 'coercion' command, constant expected", pos);
        return add_coercion(p.env(), const_name(f), const_name(C), p.ios());
    } else {
        return add_coercion(p.env(), const_name(f), p.ios());
    }
}

environment opaque_hint_cmd(parser & p) {
    environment env = p.env();
    bool found = false;
    while (p.curr_is_token(g_lparen)) {
        p.next();
        bool hiding;
        auto pos = p.pos();
        if (p.curr_is_token_or_id(g_hiding))
            hiding = true;
        else if (p.curr_is_token_or_id(g_exposing))
            hiding = false;
        else
            throw parser_error("invalid 'opaque_hint', 'hiding' or 'exposing' expected", pos);
        p.next();
        while (!p.curr_is_token(g_rparen)) {
            if (p.curr_is_token(g_module)) {
                found = true;
                p.next();
                env = set_hide_main_opaque(env, hiding);
            } else {
                name c  = p.check_constant_next("invalid 'opaque_hint', constant expected");
                found   = true;
                if (hiding)
                    env = hide_definition(env, c);
                else
                    env = expose_definition(env, c);
            }
        }
        p.next();
    }
    if (!found)
        throw exception("invalid empty 'opaque_hint' command");
    return env;
}

environment namespace_cmd(parser & p) {
    auto pos = p.pos();
    name n = p.check_atomic_id_next("invalid namespace declaration, atomic identifier expected");
    if (is_root_namespace(n))
        throw parser_error(sstream() << "invalid namespace name, '" << n << "' is reserved", pos);
    return push_scope(p.env(), p.ios(), n);
}

static expr parse_notation_expr(parser & p, buffer<expr> const & locals) {
    auto pos = p.pos();
    expr r = p.parse_expr();
    r = abstract(r, locals.size(), locals.data());
    check_notation_expr(r, pos);
    return r;
}

static name parse_quoted_symbol_or_token(parser & p, buffer<token_entry> & new_tokens, bool & used_default, notation_entry_group grp) {
    used_default = false;
    if (p.curr_is_quoted_symbol()) {
        environment const & env = p.env();
        auto pp_tk = p.get_name_val();
        auto tks   = utf8_trim(pp_tk.to_string());
        auto tkcs  = tks.c_str();
        check_not_forbidden(tkcs);
        p.next();
        if (p.curr_is_token(get_colon_tk())) {
            p.next();
            unsigned prec = parse_precedence(p);
            new_tokens.push_back(mk_token_entry(tkcs, prec, grp));
        } else if (!get_precedence(env, tkcs, grp)) {
            new_tokens.push_back(mk_token_entry(tkcs, LEAN_DEFAULT_PRECEDENCE, grp));
            used_default = true;
        }
        return pp_tk;
    } else if (p.curr_is_keyword()) {
        auto tk = p.get_token_info().token();
        check_not_forbidden(tk.to_string().c_str());
        p.next();
        return tk;
    } else {
        throw parser_error("invalid notation declaration, symbol expected", p.pos());
    }
}

environment set_line_cmd(parser & p) {
    if (!p.curr_is_numeral())
        throw parser_error("invalid #setline command, numeral expected", p.pos());
    unsigned r = p.get_small_nat();
    p.set_line(r);
    p.next();
    return p.env();
}

static void parse_notation_local(parser & p, buffer<expr> & locals) {
    if (p.curr_is_identifier()) {
        name n = p.get_name_val();
        p.next();
        expr local_type = mk_Prop(); // type used in notation local declarations, it is irrelevant
        expr l = mk_local(n, local_type); // remark: the type doesn't matter
        p.add_local(l);
        locals.push_back(l);
    } else {
        throw parser_error("invalid notation declaration, identifier expected", p.pos());
    }
}

environment set_option_cmd(parser & p) {
    auto id_pos = p.pos();
    name id = p.check_id_next("invalid set option, identifier (i.e., option name) expected");
    auto decl_it = get_option_declarations().find(id);
    if (decl_it == get_option_declarations().end()) {
        // add "lean" prefix
        name lean_id = name("lean") + id;
        decl_it = get_option_declarations().find(lean_id);
        if (decl_it == get_option_declarations().end()) {
            throw parser_error(sstream() << "unknown option '" << id << "', type 'help options.' for list of available options", id_pos);
        } else {
            id = lean_id;
        }
    }
    option_kind k = decl_it->second.kind();
    if (k == BoolOption) {
        if (p.curr_is_token_or_id(g_true))
            p.set_option(id, true);
        else if (p.curr_is_token_or_id(g_false))
            p.set_option(id, false);
        else
            throw parser_error("invalid Boolean option value, 'true' or 'false' expected", p.pos());
        p.next();
    } else if (k == StringOption) {
        if (!p.curr_is_string())
            throw parser_error("invalid option value, given option is not a string", p.pos());
        p.set_option(id, p.get_str_val());
        p.next();
    } else if (k == DoubleOption) {
        p.set_option(id, p.parse_double());
    } else if (k == UnsignedOption || k == IntOption) {
        p.set_option(id, p.parse_small_nat());
    } else {
        throw parser_error("invalid option value, 'true', 'false', string, integer or decimal value expected", p.pos());
    }
    p.updt_options();
    return p.env();
}

environment print_cmd(parser & p) {
    if (p.curr() == scanner::token_kind::String) {
        p.regular_stream() << p.get_str_val() << endl;
        p.next();
    } else if (p.curr_is_token_or_id(g_raw)) {
        p.next();
        expr e = p.parse_expr();
        p.regular_stream() << e << endl;
    } else if (p.curr_is_token_or_id(g_options)) {
        p.next();
        p.regular_stream() << p.ios().get_options() << endl;
    } else {
        throw parser_error("invalid print command", p.pos());
    }
    return p.env();
}

static unsigned parse_precedence_core(parser & p) {
    auto pos = p.pos();
    if (p.curr_is_numeral()) {
        return p.parse_small_nat();
    } else {
        environment env = p.env();
        env = open_prec_aliases(env);
        parser::local_scope scope(p, env);
        expr pre_val = p.parse_expr(get_max_prec());
        pre_val  = mk_typed_expr(mk_constant(get_num_name()), pre_val);
        expr val = std::get<0>(p.elaborate(pre_val, list<expr>()));
        val = normalize(p.env(), val);
        if (optional<mpz> mpz_val = to_num_core(val)) {
            if (!mpz_val->is_unsigned_int())
                throw parser_error("invalid 'precedence', argument does not fit in a machine integer", pos);
            return mpz_val->get_unsigned_int();
        } else {
            throw parser_error("invalid 'precedence', argument does not evaluate to a numeral", pos);
        }
    }
}

// auxiliary procedure used by local_notation_cmd and reserve_cmd
static environment dispatch_notation_cmd(parser & p, bool overload, notation_entry_group grp, bool persistent) {
    if (p.curr_is_token(get_notation_tk())) {
        p.next();
        return notation_cmd_core(p, overload, grp, persistent);
    } else if (p.curr_is_token(get_infixl_tk())) {
        p.next();
        return mixfix_cmd(p, mixfix_kind::infixl, overload, grp, persistent);
    } else if (p.curr_is_token(get_infix_tk())) {
        p.next();
        return mixfix_cmd(p, mixfix_kind::infixl, overload, grp, persistent);
    } else if (p.curr_is_token(get_infixr_tk())) {
        p.next();
        return mixfix_cmd(p, mixfix_kind::infixr, overload, grp, persistent);
    } else if (p.curr_is_token(get_prefix_tk())) {
        p.next();
        return mixfix_cmd(p, mixfix_kind::prefix, overload, grp, persistent);
    } else if (p.curr_is_token(get_postfix_tk())) {
        p.next();
        return mixfix_cmd(p, mixfix_kind::postfix, overload, grp, persistent);
    } else {
        throw parser_error("invalid local/reserve notation, 'infix', 'infixl', 'infixr', 'prefix', "
                           "'postfix' or 'notation' expected", p.pos());
    }
}

void decl_attributes::parse(parser & p) {
    buffer<char const *> attr_tokens;
    get_attribute_tokens(attr_tokens);
    while (true) {
        auto pos   = p.pos();
        if (auto it = parse_priority(p)) {
            m_prio = *it;
            bool has_prio_attr = false;
            for (auto const & entry : m_entries) {
                if (get_attribute_kind(entry.m_attr.c_str()) == attribute_kind::Prioritized) {
                    has_prio_attr = true;
                    break;
                }
            }
            if (!has_prio_attr) {
                throw parser_error("invalid '[priority]' attribute, declaration has not been marked with a prioritized attribute", pos);
            }
        } else if (p.curr_is_token(get_parsing_only_tk())) {
            if (!m_is_abbrev)
                throw parser_error("invalid '[parsing_only]' attribute, only abbreviations can be "
                                   "marked as '[parsing_only]'", pos);
            m_parsing_only = true;
            p.next();
        } else {
            bool found = false;
            for (char const * tk : attr_tokens) {
                if (p.curr_is_token(tk)) {
                    p.next();
                    char const * attr = get_attribute_from_token(tk);
                    for (auto const & entry : m_entries) {
                        if (are_incompatible(entry.m_attr.c_str(), attr)) {
                            throw parser_error(sstream() << "invalid attribute [" << attr
                                               << "], declaration was already marked with [" << entry.m_attr << "]", pos);
                        }
                    }
                    switch (get_attribute_kind(attr)) {
                    case attribute_kind::Default:
                    case attribute_kind::Prioritized:
                        m_entries = cons(entry(attr), m_entries);
                        break;
                    case attribute_kind::Parametric: {
                        unsigned v = p.parse_small_nat();
                        if (v == 0)
                            throw parser_error("invalid attribute parameter, value must be positive", pos);
                        p.check_token_next(get_rbracket_tk(), "invalid attribute, ']' expected");
                        m_entries = cons(entry(attr, v-1), m_entries);
                        break;
                    }
                    case attribute_kind::OptParametric:
                        if (!p.curr_is_token(get_rbracket_tk())) {
                            unsigned v = p.parse_small_nat();
                            if (v == 0)
                                throw parser_error("invalid attribute parameter, value must be positive", pos);
                            p.check_token_next(get_rbracket_tk(), "invalid attribute, ']' expected");
                            m_entries = cons(entry(attr, v-1), m_entries);
                        } else {
                            p.check_token_next(get_rbracket_tk(), "invalid attribute, ']' expected");
                            m_entries = cons(entry(attr), m_entries);
                        }
                        break;
                    case attribute_kind::MultiParametric: {
                        buffer<unsigned> vs;
                        while (true) {
                            unsigned v = p.parse_small_nat();
                            if (v == 0)
                                throw parser_error("invalid attribute parameter, value must be positive", pos);
                            vs.push_back(v-1);
                            if (p.curr_is_token(get_rbracket_tk()))
                                break;
                        }
                        p.next();
                        m_entries = cons(entry(attr, to_list(vs)), m_entries);
                        break;
                    }
                    }
                    found = true;
                    break;
                }
            }
            if (!found)
                break;
        }
    }
}