Re: how to prevent bugs without static type checking?
[
Date Prev][
Date Next][
Thread Prev][
Thread Next]
[
Date Index]
[
Thread Index]
- Subject: Re: how to prevent bugs without static type checking?
- From: Geoff Leyland <geoff_leyland@...>
- Date: 2012年10月25日 10:28:45 +1300
On 25/10/2012, at 8:43 AM, eugeny gladkih <john@gladkih.com> wrote:
>> --- prints the string s n times
>> -- @tparam number n how many times to print the string
>> -- @tparam string s the string to print
>> function printn(s, n)
>> for i = 1, n do print(s) end
>> end
>>
>> printn(10, "hello")
>
> what about
>
> printn("hello",'10')
>
> ?
As in, does the "number" constraint check whether tonumber (or automatic type coercion) can coerce the argument into a number? Currently, no, it just does 'type(value) == constraint'. It'd be easy to change, but I get the feeling automatic coercion is not always a popular feature.
But you can go:
function printn(
s, -- string
n) -- number|string
or, for that matter
function printn(
s, -- string
n) -- 1..640: 640 ought to be enough for anybody
and so on.