pocketpy/src/repl.h

#pragma once

#include "compiler.h"
#include "ceval.h"

#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
#include <Windows.h>
#endif

namespace pkpy{

#ifdef _WIN32

inline std::string getline(bool* eof=nullptr) {
    HANDLE hStdin = GetStdHandle(STD_INPUT_HANDLE);
    std::wstringstream wss;
    WCHAR buf;
    DWORD read;
    while (ReadConsoleW(hStdin, &buf, 1, &read, NULL) && buf != L'\n') {
        if(eof && buf == L'\x1A') *eof = true;  // Ctrl+Z
        wss << buf;
    }
    std::wstring wideInput = wss.str();
    int length = WideCharToMultiByte(CP_UTF8, 0, wideInput.c_str(), (int)wideInput.length(), NULL, 0, NULL, NULL);
    std::string output;
    output.resize(length);
    WideCharToMultiByte(CP_UTF8, 0, wideInput.c_str(), (int)wideInput.length(), &output[0], length, NULL, NULL);
    if(!output.empty() && output.back() == '\r') output.pop_back();
    return output;
}

#else

inline std::string getline(bool* eof=nullptr){
    std::string line;
    if(!std::getline(std::cin, line)){
        if(eof) *eof = true;
    }
    return line;
}

#endif

class REPL {
protected:
    int need_more_lines = 0;
    std::string buffer;
    VM* vm;
public:
    REPL(VM* vm) : vm(vm){
        vm->_stdout(vm, "pocketpy " PK_VERSION " (" __DATE__ ", " __TIME__ ") ");
        vm->_stdout(vm, fmt("[", sizeof(void*)*8, " bit]" "\n"));
        vm->_stdout(vm, "https://github.com/blueloveTH/pocketpy" "\n");
        vm->_stdout(vm, "Type \"exit()\" to exit." "\n");
    }

    bool input(std::string line){
        CompileMode mode = REPL_MODE;
        if(need_more_lines){
            buffer += line;
            buffer += '\n';
            int n = buffer.size();
            if(n>=need_more_lines){
                for(int i=buffer.size()-need_more_lines; i<buffer.size(); i++){
                    // no enough lines
                    if(buffer[i] != '\n') return true;
                }
                need_more_lines = 0;
                line = buffer;
                buffer.clear();
                mode = CELL_MODE;
            }else{
                return true;
            }
        }
        
        try{
            vm->exec(line, "<stdin>", mode);
        }catch(NeedMoreLines& ne){
            buffer += line;
            buffer += '\n';
            need_more_lines = ne.is_compiling_class ? 3 : 2;
            if (need_more_lines) return true;
        }
        return false;
    }
};

} // namespace pkpy