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