Re: discrepancy between luaL_tolstring and lua_tolstring

[书呆彭, Peng Yi <nerditation@...>]

在 2016/7/3 23:31, Viacheslav Usov 写道:
> Is there any profound reason why luaL_tolstring can convert numbers, Boolean and nil values (and other things), while the other one can only convert numbers?
>
> Cheers,
> V.

in other scripting languages like Python, your host program use PyObject (and subtypes such as PyStringObject) directly.

but in Lua you are not supposed to use TValue or TString directly: they are internal to Lua. you must use the Lua API

to convert between various Lua types and the according C types via the stack. the function `lua_tolstring` is of the family

to convert value from Lua to C, others of the same family includes `lua_tonumber`, `lua_toboolean`, `lua_touserdata`.


the fact that `lua_tolstring` also accept a number value is just a side effect of the way Lua coerce number and string.


while the `luaL_tolstring` is a library function (instead of the core API) and is really meant to be a _converter_ which

convert various Lua values to its string representation. it's the C counterpart of the Lua side function tostring.


this is how I see the difference between the two functions. correct me if I am wrong.



--

the nerdy Peng / 书呆彭 / Sent from Thunderbird