xref: /freebsd/contrib/lutok/examples/interpreter.cpp (revision c697fb7f7cc9bedc5beee44d35b771c4e87b335a)

// Copyright 2012 Google Inc.
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/// \file examples/interpreter.cpp
/// Implementation of a basic command-line Lua interpreter.

#include <cstdlib>
#include <iostream>
#include <string>

#include <lutok/exceptions.hpp>
#include <lutok/operations.hpp>
#include <lutok/state.ipp>


/// Executes a Lua statement provided by the user with error checking.
///
/// \param state The Lua state in which to process the statement.
/// \param line The textual statement provided by the user.
static void
run_statement(lutok::state& state, const std::string& line)
{
    try {
        // This utility function allows us to feed a given piece of Lua code to
        // the interpreter and process it.  The piece of code can include
        // multiple statements separated by a semicolon or by a newline
        // character.
        lutok::do_string(state, line, 0, 0, 0);
    } catch (const lutok::error& error) {
        std::cerr << "ERROR: " << error.what() << '\n';
    }
}


/// Program's entry point.
///
/// \return A system exit code.
int
main(void)
{
    // Create a new session and load some standard libraries.
    lutok::state state;
    state.open_base();
    state.open_string();
    state.open_table();

    for (;;) {
        std::cout << "lua> ";
        std::cout.flush();

        std::string line;
        if (!std::getline(std::cin, line).good())
            break;
        run_statement(state, line);
    }

    return EXIT_SUCCESS;
}