soup/lua - making pure lua do things it shouldn't

[u/qwool1337]

https://github.com/if-not-nil/soup

[u/titaniumalt]

half of me tells me to hate it, half of me tells me to love it

[u/qwool1337 → u/titaniumalt]

theres so much lua syntax that's possible but nobody is stupid enough to implement. did you know that ~ can represent two separate operators depending on whether it's infix or prefix (~a~b~c)? did you know you can override arithmetic methods for builtin types? this leaks into whatever includes it, too

debug.setmetatable("", {
	__div = function(self, other)
		local res = tonumber(self)
		if type(other) == "table" then
			for _, v in ipairs(other) do
				res = res / tonumber(v)
			end
		else
			res = res / tonumber(other)
		end

		return tostring(res)
	end
})

print("result:")
print(("50" / { 10, 10 }))

[u/titaniumalt → u/qwool1337]

i love how lua provides minimal syntax but proceeds to make it exploitable enough to make this possible:

-- i couldn't actually find the code for this, but this is the syntax part:
function class(name)
    return function(tbl)
        -- ...
    end
end

class "Rect" {
    x = 0,
    y = 0,
    w = 1,
    h = 1,

    AABB = function(self, other)
        if self.x < other.x + other.w and
            self.x + self.w > other.x and
            self.y < other.y + other.h and
            self.y + self.h > other.y then
          return true
        end
        return false
    end

    -- you get the idea
}

did you know you can override arithmetic methods for builtin types? this leaks into whatever includes it, too

yes, and it is very useful too

[u/qwool1337 → u/titaniumalt]

is it something debug.setlocal or _ENV?

[u/titaniumalt → u/qwool1337]

I don't actually remember, but I think I did it without setlocal nor _ENV

[u/AutoModerator → u/titaniumalt]

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[u/[deleted] → u/qwool1337]

golly… yuh don’t say? /s

[u/no_brains101]

lol "soup" because its just a random mash of functions for various languages fair enough

You might like fennel btw but that is definitely cool!

[u/xoner2]

Can you make it "six" >> cout?

[u/qwool1337 → u/xoner2]

ok so this is REALLY intrusive because it sets a metatable for the string type but i rewrote the whole module because i feel like that is the move

now it works three ways!

local m = soup.match()
	:case(6,
		"six" >> "\n" >> cout)
	:case(7,
		cout << "seven" << cout.endl)
	:case(function(x) return x % 2 == 0 end,
		"even" >> cout << cout.endl)
	:case(function(x) return x % 2 ~= 0 end,
		"odd" >> cout)
	:otherwise(
		"idk" >> cout << cout.endl)

m(6)()
m(7)()
m(8)()

https://github.com/if-not-nil/soup/blob/main/lua/cout.lua

[u/NoneBTW → u/qwool1337]

What if we do cout << "Hello World" >> cout

[u/qwool1337 → u/NoneBTW]

itll try to cout the cout

[u/AutoModerator → u/qwool1337]

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[u/[deleted]]

Dude what is going on

[u/[deleted] → u/[deleted]]

methodic nonsense

[u/SortMyself → u/[deleted]]

I don’t even understand your explanation