lean2/tests/lean/lua15.lean

Variables i j : Int
Variable p : Bool

(**
 local env = get_environment()
 ok, ex = pcall(
    function()
       print(parse_lean("i + p"))
 end)
 assert(not ok)
 assert(is_exception(ex))
 print(ex:what())
 ex:rethrow()
**)
feat(lua): improve error handling in Lua API Signed-off-by: Leonardo de Moura <leonardo@microsoft.com> 2013-11-17 02:21:42 +00:00			`Variables i j : Int`
			`Variable p : Bool`

			`(**`
			`local env = get_environment()`
refactor(util/lua): propagate C++ Lean exceptions in Lua The following call sequence is possible: C++ -> Lua -> C++ -> Lua -> C++ The first block of C++ is the Lean main function. The main function invokes the Lua interpreter. The Lua interpreter invokes a C++ Lean API. Then the Lean API invokes a callback implemented in Lua. The Lua callback invokes another Lean API. Now, suppose the Lean API throws an exception. We want the C++ exception to propagate over the mixed C++/Lua call stack. We use the clone/rethrow exception idiom to achieve this goal. Before this commit, the C++ exceptions were converted into strings using the method what(), and then they were propagated over the Lua stack using lua_error. A lua_error was then converted into a lua_exception when going back to C++. This solution was very unsatisfactory, since all C++ exceptions were being converted into a lua_exception, and consequently the structure of the exception was being lost. Signed-off-by: Leonardo de Moura <leonardo@microsoft.com> 2013-11-27 20:19:54 +00:00			`ok, ex = pcall(`
feat(lua): improve error handling in Lua API Signed-off-by: Leonardo de Moura <leonardo@microsoft.com> 2013-11-17 02:21:42 +00:00			`function()`
			`print(parse_lean("i + p"))`
			`end)`
			`assert(not ok)`
refactor(util/lua): propagate C++ Lean exceptions in Lua The following call sequence is possible: C++ -> Lua -> C++ -> Lua -> C++ The first block of C++ is the Lean main function. The main function invokes the Lua interpreter. The Lua interpreter invokes a C++ Lean API. Then the Lean API invokes a callback implemented in Lua. The Lua callback invokes another Lean API. Now, suppose the Lean API throws an exception. We want the C++ exception to propagate over the mixed C++/Lua call stack. We use the clone/rethrow exception idiom to achieve this goal. Before this commit, the C++ exceptions were converted into strings using the method what(), and then they were propagated over the Lua stack using lua_error. A lua_error was then converted into a lua_exception when going back to C++. This solution was very unsatisfactory, since all C++ exceptions were being converted into a lua_exception, and consequently the structure of the exception was being lost. Signed-off-by: Leonardo de Moura <leonardo@microsoft.com> 2013-11-27 20:19:54 +00:00			`assert(is_exception(ex))`
			`print(ex:what())`
			`ex:rethrow()`
feat(lua): improve error handling in Lua API Signed-off-by: Leonardo de Moura <leonardo@microsoft.com> 2013-11-17 02:21:42 +00:00			`**)`