Yerbacon/src/headers/transpiler/Target.hpp

#ifndef YERBACON_TARGET_HPP
#define YERBACON_TARGET_HPP

#include <vector>
#include <string_view>
#include <iostream>
#include <memory>
#include <sstream>
#include <cstring>
#include <unordered_map>
#include <typeindex>
#include <limits>
#ifdef __GNUC__
#include <cxxabi.h>
#endif

#include "../parsing/ParseComponents.hpp"

class Target {
    constexpr static const char* const interpolationString = "${";
    constexpr static const char* const interpolationCloseString = "}";
protected:
    inline bool supportsOneLine() { return uniqueLineSeparator().has_value(); };
    std::stringstream output;
    inline void stringInterpolation(const char* multiline, const string& view) { stringInterpolation(view, multiline, multiline); }
    void stringInterpolation(string view, const char* openMultiline = "", const char* closeMultiline = "", const char* concatenationCharacters = "+") {
        typedef string::size_type strSize;
        vector<strSize> interpolationVector;
        strSize occurrence_position = view.find(interpolationString);
        if (view.find(interpolationCloseString) != string::npos) {
            while (occurrence_position != string::npos) {
                interpolationVector.push_back(occurrence_position);
                occurrence_position = view.find(interpolationString, occurrence_position + strlen(interpolationString));
            }
        }
        strSize newLine = view.find('\n');
        const bool multiline = newLine != string::npos && not !strcmp(openMultiline, "") && not !strcmp(closeMultiline, openMultiline);
        if (not multiline) {
            while (newLine != string::npos) {
                view.erase(newLine, 1);
                view.insert(newLine, "\\n");
                newLine = view.find('\n', newLine);
            }
        }
        const char* const openCharacters = multiline ? openMultiline : "\"";
        decltype(openCharacters) closeCharacters = multiline ? closeMultiline : openCharacters;
        if (not interpolationVector.empty()) {
            strSize closingBrace = 0;
            for (unsigned long i = 0; i < interpolationVector.size(); ++i) {
                const auto& occurrence = interpolationVector[i];
                const bool hasNext = (i + 1) < interpolationVector.size();
                if (i > 0) output << concatenationCharacters;
                output << openCharacters << view.substr(closingBrace + (i > 0), (occurrence - closingBrace) - (i > 0));
                closingBrace = view.find_first_of(interpolationCloseString, occurrence);
                const bool closingBraceIsNPOS = closingBrace == string::npos;
                const bool wrongClosingBrace = !closingBraceIsNPOS && ((hasNext && closingBrace > interpolationVector[i + 1]));
                if (closingBraceIsNPOS || wrongClosingBrace) {
                    output << view.substr(occurrence, (hasNext ? interpolationVector[i + 1] - occurrence : string::npos));
                }
                output << closeCharacters;
                if (not closingBraceIsNPOS && not wrongClosingBrace) {
                    output << concatenationCharacters;
                    output << view.substr(occurrence + strlen(interpolationString), (closingBrace - occurrence) - strlen(interpolationString));
                }
            }
        } else output << openCharacters << view << closeCharacters;
    }
    typedef function<void (const ParseTree& parsedTree, unsigned int& index)> task;
    #define make_task_base(start, type, captures, function_body) make_pair(type_index(typeid(type)), [captures](const ParseTree& parsedTree, unsigned int& index) { start; function_body })
    #define make_task_base_R(T, C, F) make_task_base(const T& parseComponent = reinterpret_cast<T&>(*parsedTree[index]), T, C, F)
    #define make_task(T, F) make_task_base_R(T, this, F)
    #define make_task_noR(T, F) make_task_base(,T, this, F)
    #define make_nonlocal_task(T, F) make_task_base_R(T, , F)
    typedef unordered_map<type_index, task> unordered_task_map;
    typedef pair<const char*, const char*> print_functions_pair;
    virtual unordered_task_map getTaskMap() = 0;
    virtual print_functions_pair printFunctions() = 0;
    IS(ParseTree)
    void transpileTree(const T& parseTree, const unsigned short& indentationLevel = 0, const function<void(decltype(parseTree.cbegin())&)>&& postInsertionFunction = [](auto&){}) {
        if (not parseTree.empty()) {
            const auto added_size = indentationLevel * strlen(indentation);
            if (newLines) {
                separator.reserve(separator.size() + added_size);
                for (unsigned short level = 0; level < indentationLevel; ++level) {
                    separator.append(indentation);
                }
            }
            unsigned int subIndex = 0;
            for (auto pointer_iterator = parseTree.cbegin(); pointer_iterator < parseTree.cend(); ++pointer_iterator) {
                const type_info& id = pointer_iterator->get()->getId();
                try {
                    getTaskMapInstance().at(id)(parseTree, subIndex); ++subIndex;
                } catch (const out_of_range&) {
                    throw Yerbacon::Exception(string(
                        #ifndef __GNUC__
                            id.name()
                        #else
                            abi::__cxa_demangle(id.name(), nullptr, nullptr, nullptr)
                        #endif
                    ) += " is not supported by the current target");
                }
                postInsertionFunction(pointer_iterator);
            }
            if (newLines) separator.erase(separator.size() - added_size);
        }
    }
    IS(ParseTree)
    void separate_transpileTree(const T& parseTree, const unsigned short& indentationLevel = 0) {
        transpileTree(parseTree, indentationLevel, [this, &parseTree](const auto& iterator){
            if ((newLines || iterator + 1 == parseTree.cend()) && use_uniqueLineSeparator()) output << uniqueLineSeparator().value();
            if (iterator + 1 != parseTree.cend()) output << separator;
        });
    }
    IS(ParseTree)
    void separate_transpileTree(const T& parseTree, const string_view separation_characters) {
        transpileTree(parseTree, 0, [this, &parseTree, &separation_characters](const auto& iterator){
            if (iterator + 1 != parseTree.cend()) { output << separation_characters; }
        });
    }
    typedef optional<const char*> optional_string;
    virtual optional_string uniqueLineSeparator() { return ";"; };
    virtual bool use_uniqueLineSeparator() { return false; };
    const bool newLines;
    string separator;
    static constexpr const char* indentation = "  ";
public:
    unordered_task_map getTaskMapInstance() {
        unordered_task_map fullMap = getTaskMap();
        // Default / Shared tasks:
        fullMap.merge(unordered_task_map({
            make_task(ParseTree, transpileTree(parseComponent);),
            make_task(StandardComponents::Reference, output << parseComponent.name;),
            make_task(StandardComponents::Call,
                const auto print_functions = printFunctions();
                using enum ReservedIdentifier;
                output << ((parseComponent.name == ID(PRINT_FUNCTION)) ? print_functions.first : (parseComponent.name == ID(PRINT_LINE_FUNCTION)) ? print_functions.second : parseComponent.name) << '(';
                separate_transpileTree(parseComponent, ", ");
                output << ')';
            ),
            make_task(StandardComponents::types::Integer, output << setprecision(parseComponent.precision) << fixed << parseComponent.value;)
        }));
        return fullMap;
    };
    static unique_ptr<Target> forName(string_view name, bool newLines);
    string transpileWithTree(const ParseTree& tree) {
        separator = newLines ? "\n" : (supportsOneLine() ? uniqueLineSeparator().value() : throw Yerbacon::Exception("--newlines=off is not supported by the current target"));
        output.str(string());
        separate_transpileTree(tree);
        return output.str() + '\n';
    };
    explicit Target(const bool& newLines): output(), newLines(newLines), separator() {};
    Target() = delete;
    virtual ~Target() = default;
};

#include "implementations/Lua.hpp"
#include "implementations/Js.hpp"
#include "implementations/Py.hpp"
#include "implementations/GodotScript.hpp"

unique_ptr<Target> Target::forName(string_view name, const bool newLines = true) {
    #define ADDTARGET(X, target_class) if (name == X) return unique_ptr<target_class>(new target_class(newLines))
    ADDTARGET("lua", LuaTarget);
    ADDTARGET("js", JsTarget);
    ADDTARGET("py", PyTarget);
    ADDTARGET("gd", GsTarget);
    #undef ADDTARGET
    #undef make_nonlocal_task
    #undef make_task_noR
    #undef make_task
    #undef make_task_base_R
    #undef make_task_base
    Yerbacon::fail({"\"", string(1, (char) toupper(name.at(1))).data(), name.substr(2).data(), "\" is not a valid target."});
    return nullptr;
}

#endif //YERBACON_TARGET_HPP