Re: Lua 5.4-work1 with first class arrays (implementation & benchmarks)
[
Date Prev][
Date Next][
Thread Prev][
Thread Next]
[
Date Index]
[
Thread Index]
- Subject: Re: Lua 5.4-work1 with first class arrays (implementation & benchmarks)
- From: Sean Conner <sean@...>
- Date: 2018年3月28日 15:03:42 -0400
It was thus said that the Great Duane Leslie once stated:
>
> When I spoke about *generic* I meant a length value that was always equal
> to the largest index in the table.
There are problems with assuming the length of the "array" portion of a
table is the largest integer key:
-- Assume that the length of a Lua sequence is the largest
-- integer index in the table.
x = { [500] = true }
-- The length of x is now 500
table.remove(x)
-- This removes an entry from the array and moves everything down
-- one spot (documented behavior). By default, table.remove()
-- removes the last element, so there shouldn't be an entry for
-- x[500]
print(x[500])
-- well, look at that! Now, look at this:
table.remove(x,1)
-- This should remove the first element and shift everything thing
-- down one. So x[500] will now be x[499]
print(x[499])
-- hmmm ..
print(x[500])
-- Um ...
This doesn't quite work for stock Lua.
-spc