integration/luprex/cpp/luaconsole.hpp

//////////////////////////////////////////////////////
//
// LuaConsole:
//
// Used to parse commands that are being interactively typed
// in by a user.
//
// The command syntax is always a single character command,
// followed by arguments.  Only two commands are hardwired:
//
//    l - evaluate lua expression
//    r - evaluate lua expression with 'return' prepended
//
// The console expects you to add lines of text one at a time.
// After adding a line, the console will recommend one of these
// actions:
//
// 1. DO_NOTHING: Add more lines of text.
// 2. DO_LUA: Evaluate a lua expression.
// 3. DO_OTHER: Execute a non-lua command.
// 4. DO_SYNTAX: Print a lua syntax error.
//
//////////////////////////////////////////////////////

#ifndef LUACONSOLE_HPP
#define LUACONSOLE_HPP

#include <string>
#include "luastack.hpp"

class LuaConsole {
public:
    enum {
        DO_NOTHING,  // We need more input text.
        DO_COMMAND,  // We have a valid slash command.
        DO_LUA,      // We have a valid lua expression.
        DO_SYNTAX,   // We have a syntax error.
    };
    using StringVec = std::vector<std::string>;

private:
    lua_State *lua_state_;
    int action_;
    std::string raw_input_;
    int lines_;
    std::string lua_expression_;
    StringVec words_;
    std::string syntax_;

    void split_words();

public:
    LuaConsole();
    ~LuaConsole();

    // Get the recommended action.
    int action() const { return action_; }

    // When action is DO_COMMAND, get the command words.
    const StringVec &words() const { return words_; }

    // When action is DO_LUA, get the valid lua expression.
    std::string lua_expression() const { return lua_expression_; }

    // When action is DO_SYNTAX, get the syntax error.
    const std::string &syntax() const { return syntax_; }

    // Add a line of text that was just read from the console.
    void add(std::string line);

    // Read a line of text from stdin and add it.
    void add_stdin();

    // Clear the state.
    void clear();
};

#endif // LUACONSOLE_HPP