2015年01月14日 2:59 GMT-02:00 Dirk Laurie
<dirk.laurie@gmail.com>:
2015年01月14日 2:06 GMT+02:00 Aapo Talvensaari <
aapo.talvensaari@gmail.com>:
> One correction to docs:
>
> utf8.len docs say:
>
> "If it finds any invalid byte sequence, returns a false value plus the
> position of the first invalid byte."
>
> It actually seems to return nil (which is of course evaluated as false when
> not compared equality to false).
"all logical operators consider both false and nil as false".
The manual also sometimes states "returns false",
I understand the intended meaning of "return a false value" in the docs, but I also understand Aapo Talvensaari's comment because "false value" name it as a value (and Lua has a value for "false"), but nil, despite a value in Lua, means "Not a Value", or none of the possible values. In a closed context, which is mostly the case, nil may be interpreted as "false", that is, negation by failure.