Re: Has Lua reached perfection?

["Soni \"They/Them\" L." <fakedme@...>]

On 2018-01-28 12:49 PM, Paige DePol wrote:
> Soni They/Them L. <fakedme@gmail.com> wrote:
>
> > On 2018-01-28 12:19 PM, Paige DePol wrote:
> > > Soni They/Them L. <fakedme@gmail.com> wrote:
> > >
> > > > On 2018-01-28 12:04 PM, Paige DePol wrote:
> > > > > Soni They/Them L. <fakedme@gmail.com> wrote:
> > > > >
> > > > > > I want a switch where you can use math.random() in switch cases and it
> > > > > > lazy-evaluates them and just works.
> > > > > What practical use would that even have?
> > > > >
> > > > > ~Paige
> > > > It's equivalent to if...elseif chains and supports ==
> > > I meant using math.random() as a case value.
> > >
> > > I think I'd need to see a code example of what you mean
> > > to understand how this switch block would work.
> > >
> > > ~Paige
> > It's just a natural consequence of evaluating them in-order and supporting
> > ==, like a desugaring into if...elseif chains.
> So, you're saying you'd want something like "case math.random() == 12"?
>
> The case blocks themselves are already essentially == comparisons to the initial
> value being switch'd... so couldn't you just do "switch math.random()" and then
> do case blocks for each random value you wanted results for? Without you giving
> some sort of pseudo-code example I am just grasping at your meaning here! ;)
>
> I also came up short trying to search for examples for what you are asking by
> searching for "lazy evaluation switch case" but that came up blank for the most
> part. However, I did discover that the language Python also does not have any
> support for switch/case, and their reasoning[1] seems to be the same as Lua:
>
>
> You can do this easily enough with a sequence of if... elif... elif... else.
> For cases where you need to choose from a very large number of possibilities,
> you can create a dictionary mapping case values to functions to call.
>
> There have been some proposals for switch statement syntax, but there is no
> consensus (yet) on whether and how to do range tests. See PEP 275[2] for
> complete details and the current status.
>
>
> By the status of the PEP it doesn't look like Python will be getting a native
> switch/case statement any time soon. However, it looks like I pretty much
> implemented PEP 275 for Lua! :)
>
> ~Paige
>
> [1] https://docs.python.org/2/faq/design.html#why-isn-t-there-a-switch-or-case-statement-in-python
>
> [2] https://www.python.org/dev/peps/pep-0275/

switch x do
case math.random() do print "a" end
case math.random() do print "b" end
case math.random() do print "c" end
else do print "e" end
end

-- desugars into

if x == math.random() then print "a"
elseif x == math.random() then print "b"
elseif x == math.random() then print "c"
else print "e" end


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