obelisk/src/obelisk.cpp

#include "knowledge_base.h"
#include "lexer.h"
#include "obelisk.h"
#include "parser.h"

#include <iomanip>
#include <iostream>
#include <limits>
#include <memory>

static int mainLoop()
{
    auto parser = std::unique_ptr<obelisk::Parser> {new obelisk::Parser()};
    std::unique_ptr<obelisk::KnowledgeBase> kb;

    try
    {
        kb = std::unique_ptr<obelisk::KnowledgeBase> {
            new obelisk::KnowledgeBase("cromer.kb")};
    }
    catch (obelisk::KnowledgeBaseException& exception)
    {
        std::cout << exception.what() << std::endl;
        return EXIT_FAILURE;
    }

    // Prime the first token.
    fprintf(stderr, "ready> ");
    try
    {
        parser->getNextToken();
    }
    catch (obelisk::LexerException& exception)
    {
        std::cout << "Error: " << exception.what() << std::endl;
        return EXIT_FAILURE;
    }

    while (true)
    {
        fprintf(stderr, "ready> ");
        switch (parser->getCurrentToken())
        {
            case obelisk::Lexer::kTokenEof :
                return EXIT_SUCCESS;
            case ';' : // ignore top-level semicolons.
                std::cout << "Identifier: "
                          << parser->getLexer()->getIdentifier() << std::endl;
                std::cout << "Num: " << parser->getLexer()->getNumberValue()
                          << std::endl;
                try
                {
                    parser->getNextToken();
                }
                catch (obelisk::LexerException& exception)
                {
                    std::cout << "Error: " << exception.what() << std::endl;
                    return EXIT_FAILURE;
                }
                break;
            case obelisk::Lexer::kTokenFact :
                parser->handleFact(kb);
                break;
            case obelisk::Lexer::kTokenRule :
                // parser->handleRule();
                break;
            case obelisk::Lexer::kTokenAction :
                // parser->handleAction();
                break;
            default :
                parser->getNextToken();
                break;
        }
    }

    return EXIT_SUCCESS;
}

int main(int argc, char** argv)
{
    for (int i = 1; i < argc; i++)
    {
        std::cout << argv[i] << std::endl;
    }

    // This can be used to store a double as 2 floats in the database, then restore it back to a double.
    // Inspired by Godot's double precision on the GPU to render large worlds.
    /*try
    {
        float first;
        float second;
        double var = 0.123456789012345;

        obelisk::KnowledgeBase* kb = new obelisk::KnowledgeBase("cromer.kb");
        kb->getFloat(first, second, var);
        std::cout << std::setprecision(std::numeric_limits<double>::digits10)
                  << "Double: " << var << std::endl
                  << "First: " << first << std::endl
                  << "Second: " << second << std::endl;
        var = 0.0;
        kb->getDouble(var, first, second);
        std::cout << std::setprecision(std::numeric_limits<double>::digits10)
                  << "Double: " << var << std::endl
                  << "First: " << first << std::endl
                  << "Second: " << second << std::endl;
    }
    catch (obelisk::KnowledgeBaseException& exception)
    {
        return EXIT_FAILURE;
    }*/

    return mainLoop();
}