Re: operator overloading for string matching

[Mason Bogue <scythe+lua@...>]

@Rena:

>This is a trivial example and already looks near incomprehensible to me.

>> start, end = s:find("%s*$")
>> trailing_whitespace = end - start
>This on the other hand takes one more line and is much clearer, just
>for having fewer symbols grouped together.

I think it's really a matter of personal taste. From my perspective,
it's far more work to remember the vagaries of the different string
manipulation functions, whereas pattern-matching syntax is
semi-consistent across languages and usually easy to recognize. Also,
special characters |.%#(\)*$ etc are generally much easier to read in
programming fonts than Gmail's Helvetica. If you only use Lua and
rarely use regex-like tools (vim/sed, grep, etc) you'll probably have
a different experience.

VM limitations mean this idea is dead for now, though. Ho hum.

On Wed, Aug 19, 2015 at 3:20 PM, Pierre-Yves Gérardy <pygy79@gmail.com> wrote:
> On Tue, Aug 18, 2015 at 7:51 PM, Pierre-Yves Gérardy <pygy79@gmail.com> wrote:
>>
>> On Mon, Aug 17, 2015 at 8:57 PM, Mason Bogue <scythe+lua@ortsz.com> wrote:
>>>
>>> The proposal is this:
>>>
>>> str1 / str2 -- equivalent to str1:match(str2)
>>>
>>
>> No time to test right now, but AFAIK, binary operators return exactly one value whereas function calls can return an arbitrary number of them.
>>
>
> I remembered correctly, this is a bytecode limitation:
>
>> t = setmetatable({}, {__div = function() return 1, 2 end})
>> = t / t
> 1
>
> So this syntax would be useless for patterns that return more than one
> value, unless you change the VM to support more than one return values
> for operators.
>
> —Pierre-Yves
>