func ExampleLuaObject_Callf() {
L := luar.Init()
defer L.Close()
returns := luar.Types([]string{}) // []reflect.Type
const code = `
function return_strings()
return {'one', luar.null, 'three'}
end`
err := L.DoString(code)
if err != nil {
log.Fatal(err)
}
fun := luar.NewLuaObjectFromName(L, "return_strings")
// Using `Call` we would get a generic `[]interface{}`, which is awkward to
// work with. But the return type can be specified:
results, err := fun.Callf(returns)
if err != nil {
log.Fatal(err)
}
strs := results[0].([]string)
fmt.Println(strs[0])
// We get an empty string corresponding to a luar.null in a table,
// since that's the empty 'zero' value for a string.
fmt.Println(strs[1])
fmt.Println(strs[2])
// Output:
// one
//
// three
}
func main() {
history := os.Getenv("HOME") + "/.luar_history"
linenoise.LoadHistory(history)
defer func() {
L.Close()
linenoise.SaveHistory(history)
if x := recover(); x != nil {
fmt.Println("runtime " + x.(error).Error())
}
}()
luar.Register(L, "", luar.Map{
"__DUMMY__": &Dummy{"me"},
})
// most of this program's code is Lua....
err := L.DoString(lua_code)
if err != nil {
fmt.Println("initial " + err.Error())
return
}
// particularly the completion logic
complete := luar.NewLuaObjectFromName(L, "lua_candidates")
// this function returns a string slice of candidates
str_slice := luar.Types([]string{})
linenoise.SetCompletionHandler(func(in string) []string {
val, err := complete.Callf(str_slice, in)
if err != nil || len(val) == 1 && val[0] == nil {
return []string{}
} else {
return val[0].([]string)
}
})
register()
fmt.Println("luar 1.2 Copyright (C) 2013-2014 Steve Donovan")
fmt.Println("Lua 5.1.4 Copyright (C) 1994-2008 Lua.org, PUC-Rio")
prompt := LUA_PROMPT1
code := ""
for {
// ctrl-C/ctrl-D handling with latest update of go.linenoise
str, err := linenoise.Line(prompt)
if err != nil {
return
}
if len(str) > 0 {
if str == "exit" {
return
}
linenoise.AddHistory(str)
if str[0] == '=' || str[0] == '.' {
exprs := str[1:]
if str[0] == '=' {
str = "pprint(" + exprs + ")"
} else {
str = "println(" + exprs + ")"
}
}
continuing := false
code = code + str
//fmt.Println("'"+code+"'")
err := L.DoString(code)
if err != nil {
errs := err.Error()
// fmt.Println("err",errs)
// strip line nonsense if error occurred on prompt
idx := strings.Index(errs, ": ")
if idx > -1 && strings.HasPrefix(errs, "[string ") {
errs = errs[idx+2:]
}
// need to keep collecting line?
if strings.HasSuffix(errs, "near '<eof>'") {
continuing = true
} else {
fmt.Println(errs)
}
}
if continuing { // prompt must reflect continuing state
prompt = LUA_PROMPT2
code = code + "\n"
} else {
prompt = LUA_PROMPT1
code = ""
}
} else {
fmt.Println("empty line. Use exit to get out")
}
}
}