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#define SOL_ALL_SAFETIES_ON 1
#include <sol/sol.hpp>
#include "assert.hpp"
#include <iostream>
#include <exception>
#include <fstream>
struct custom_reader {
FILE* f;
// We use 2 here to demonstrate
// multiple calls to the function to
// parse whole file.
// Please don't use 2.
// PLEASE DO NOT USE A BUFFER
// OF SIZE 2!
char buffer[2];
std::size_t current_size;
std::size_t read_count;
custom_reader(FILE* f_) : f(f_), buffer(), current_size(0), read_count(0) {
}
bool read() {
std::cout << "custom read: read #" << ++read_count << std::endl;
current_size = fread( buffer, 1, 2, f );
return current_size > 0 && ferror(f) == 0;
}
~custom_reader( ) {
std::fclose( f );
}
};
// function must match signature found in type lua_Reader:
// const char* ( lua_State*, void*, size_t* )
const char* custom_reader_function(lua_State*, void* pointer_to_my_object, size_t* data_size) {
custom_reader& cr = *(static_cast<custom_reader*>(pointer_to_my_object));
if ( cr.read( ) ) {
*data_size = cr.current_size;
return cr.buffer;
}
else {
*data_size = 0;
return nullptr;
}
}
int main( ) {
std::cout << "=== custom reader ===" << std::endl;
// make a file to use for the custom reader
{
std::ofstream bjork("bjork.lua", std::ios::binary);
bjork << "print('hello!')\n";
}
struct on_scope_exit {
~on_scope_exit() {
// remove file when done
std::remove("bjork.lua");
}
} remove_on_exit;
sol::state lua;
lua.open_libraries( sol::lib::base );
FILE* bjork_fp;
#ifdef _MSC_VER
if ( fopen_s( &bjork_fp, "bjork.lua", "r" ) != 0 ) {
std::cerr << "failed to open bjork.lua -- exiting" << std::endl;
return -1;
}
#else
bjork_fp = fopen( "bjork.lua", "r" );
#endif
if (bjork_fp == nullptr) {
std::cerr << "failed to open bjork.lua -- exiting" << std::endl;
return -1;
}
custom_reader reader(bjork_fp);
// load the code using our custom reader, then run it
auto result = lua.safe_script( custom_reader_function, &reader, sol::script_pass_on_error );
// make sure we ran loaded and ran the code successfully
c_assert( result.valid( ) );
// note there are lua.load( ... ) variants that take a
// custom reader than JUST run the code, too!
std::cout << std::endl;
return 0;
}
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