luasocket/src/except.h
Diego Nehab 58096449c6 Manual is almost done. HTTP is missing.
Implemented new distribution scheme.
Select is now purely C.
HTTP reimplemented seems faster dunno why.
LTN12 functions that coroutines fail gracefully.
2004-06-15 06:24:00 +00:00

36 lines
1.4 KiB
C

#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 its first return
* value when it finds 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 calls "error" on the second if the first is
* nil. Otherwise, it returns all values it received.
*
* The protect function returns a new function that behaves exactly like the
* function it receives, but the new function doesn't throw exceptions: it
* returns nil followed by the error message instead.
*
* With these two function, it's easy to write functions that throw
* exceptions on error, but that don't interrupt the user script.
*
* RCS ID: $Id$
\*=========================================================================*/
#include <lua.h>
int except_open(lua_State *L);
#endif