#ifndef EXCEPT_H #define EXCEPT_H /*=========================================================================*\ * Exception control * LuaSocket toolkit (but completely independent from other modules) * * This provides support for simple exceptions in Lua. During the * development of the HTTP/FTP/SMTP support, it became aparent that * error checking was taking a substantial amount of the coding. These * function greatly simplify the task of checking errors. * * The main idea is that functions should return nil as their first return * values when they find an error, and return an error message (or value) * following nil. In case of success, as long as the first value is not nil, * the other values don't matter. * * The idea is to nest function calls with the "try" function. This function * checks the first value, and, if it's falsy, wraps the second value in a * table with metatable and calls "error" on it. Otherwise, it returns all * values it received. Basically, it works like the Lua "assert" function, * but it creates errors targeted specifically at "protect". * * The "newtry" function is a factory for "try" functions that call a * finalizer in protected mode before calling "error". * * The "protect" function returns a new function that behaves exactly like * the function it receives, but the new function catches exceptions thrown * by "try" functions and returns nil followed by the error message instead. * * With these three functions, it's easy to write functions that throw * exceptions on error, but that don't interrupt the user script. \*=========================================================================*/ #include "luasocket.h" #ifndef _WIN32 #pragma GCC visibility push(hidden) #endif int except_open(lua_State *L); #ifndef _WIN32 #pragma GCC visibility pop #endif #endif