// ProxyPairs implements Lua 5.2 'pairs' functions.
// It respects the __pairs metamethod.
//
// It is only useful for compatibility with Lua 5.1.
func ProxyPairs(L *lua.State) int {
// See Lua >=5.2 source code.
if L.GetMetaField(1, "__pairs") {
L.PushValue(1)
L.Call(1, 3)
return 3
}
L.CheckType(1, lua.LUA_TTABLE)
L.PushGoFunction(pairsAux)
L.PushValue(1)
L.PushNil()
return 3
}
// 'exist' is optional.
func run(L *lua.State, registryIndex string, code string, input *inputInfo, output *outputInfo, exist *inputInfo) error {
// Restore the sandbox.
err := L.DoString(luaRestoreSandbox)
if err != nil {
log.Fatal("Cannot load function to restore sandbox", err)
}
L.PushString(registryWhitelist)
L.GetTable(lua.LUA_REGISTRYINDEX)
err = L.Call(1, 0)
if err != nil {
log.Fatal("Failed to restore sandbox", err)
}
goToLua(L, "input", *input)
goToLua(L, "output", *output)
if exist != nil {
goToLua(L, "existinfo", *exist)
}
// Shortcut (mostly for prescript and postscript).
L.GetGlobal("input")
L.GetField(-1, "tags")
L.SetGlobal("i")
L.Pop(1)
L.GetGlobal("output")
L.GetField(-1, "tags")
L.SetGlobal("o")
L.Pop(1)
// Call the compiled script.
L.PushString(registryIndex)
L.GetTable(lua.LUA_REGISTRYINDEX)
L.PushString(code)
if L.IsTable(-2) {
L.GetTable(-2)
if L.IsFunction(-1) {
err := L.Call(0, 0)
if err != nil {
L.SetTop(0)
return fmt.Errorf("%s", err)
}
} else {
L.Pop(1)
}
} else {
L.Pop(1)
}
L.Pop(1)
// Allow tags to be numbers for convenience.
outputNumbersToStrings(L)
L.GetGlobal("output")
r := luar.LuaToGo(L, reflect.TypeOf(*output), -1)
L.Pop(1)
*output = r.(outputInfo)
return nil
}
