Why do most programming languages only have binary equality comparison operators?

Question

In natural languages, we would say \"some color is a primary color if the color is red, blue, or yellow.\"

In every programming language I\'ve seen, that translates

Answer 1

This can be replicated in Lua with some metatable magic :D

local function operator(func)
    return setmetatable({},
        {__sub = function(a, _)
            return setmetatable({a},
                {__sub = function(self, b)
                    return f(self[1], b)
                end}
            )
        end}
    )
end


local smartOr = operator(function(a, b)
    for i = 1, #b do
        if a == b[i] then
            return true
        end
    end
    return false
end)


local isPrimaryColor = someColor -smartOr- {"Red", "Blue", "Either"}

Note: You can change the name of -smartOr- to something like -isEither- to make it even MORE readable.