Re: Nitpicking about string.sub argument validity check

[Albert Chan <albertmcchan@...>]

On Aug 31, 2018, at 5:03 PM, Egor Skriptunoff <egor.skriptunoff@gmail.com> wrote:

> Hi!
>  
> It is reasonable to warn user about "string.sub" usage mistakes such as 
>    str:sub(1, 3.14) 
> that's why in Lua 5.3 string.sub might raise "number has no integer representation" error. 
>  
> But it appears that math.huge as argument also raises this error. 
> IMO, the following use cases should be considered as being valid: 
>    string.sub("abc", 2, math.huge) 
>    string.sub("abc", -math.huge, -2) 
> Yes, I know we could use -1 and 1 values respectively to get the same results, 
> but infinite values are suitable for the semantic of the function. 

How to tell if 3.14 were a mistake, and math.huge is not ?

I just felt uneasy using infinity as end-point ...
Especially bad if the infinity value is hidden behind a variable.

What is gain by not using 1 for first location, -1 for last ?