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