bool2tri

bool2tri.lua

-- https://x.com/Ziyao233/status/1872575782360649792

local inf <const> = 1/0
local bool2Tri = {
	[true] = "true",
	[false] = "false",
}

local lut = {
	equal = { [inf] = false, [true] = true, [-inf] = false },
	["greater-or-eq"] = { [inf] = true, [true] = true, [-inf] = false },
	greater = { [inf] = true, [true] = false, [-inf] = false },
	["less-or-eq"] = { [inf] = false, [true] = true, [-inf] = true },
	less = { [inf] = false, [true] = false, [-inf] = true },
	unequal = { [inf] = true, [true] = false, [-inf] = true },
}

for k,v in pairs(lut) do
	for k,t in pairs(v) do
		v[k] = bool2Tri[t]
	end
end

function test(fn, r)
	return lut[fn][r == 0 or r * inf]
end

assert(test("equal", 42) == "false")
assert(test("equal", 0) == "true")
assert(test("equal", -42) == "false")

assert(test("greater-or-eq", 42) == "true")
assert(test("greater-or-eq", 0) == "true")
assert(test("greater-or-eq", -42) == "false")

assert(test("greater", 42) == "true")
assert(test("greater", 0) == "false")
assert(test("greater", -42) == "false")

assert(test("less-or-eq", 42) == "false")
assert(test("less-or-eq", 0) == "true")
assert(test("less-or-eq", -42) == "true")

assert(test("less", 42) == "false")
assert(test("less", 0) == "false")
assert(test("less", -42) == "true")

assert(test("unequal", 42) == "true")
assert(test("unequal", 0) == "false")
assert(test("unequal", -42) == "true")