Charakterbewegungen hinzugefügt, Deko hinzugefügt, Kochrezepte angepasst

mods/futil/util/random.lua

@@ -0,0 +1,84 @@
+local f = string.format
+
+futil.random = {}
+
+function futil.random.choice(t, random)
+	random = random or math.random
+	return t[random(#t)]
+end
+
+function futil.random.weighted_choice(t, random)
+	random = random or math.random
+	local elements, weights = {}, {}
+	local i = 1
+	for element, weight in pairs(t) do
+		elements[i] = element
+		weights[i] = weight
+		i = i + 1
+	end
+	local breaks = futil.list(futil.iterators.accumulate(weights))
+	local value = random() * breaks[#breaks]
+	return elements[futil.bisect.right(breaks, value)]
+end
+
+local WeightedChooser = futil.class1()
+
+function WeightedChooser:_init(t)
+	local elements, weights = {}, {}
+	local i = 1
+	for element, weight in pairs(t) do
+		elements[i] = element
+		weights[i] = weight
+		i = i + 1
+	end
+	self._elements = elements
+	self._breaks = futil.list(futil.iterators.accumulate(weights))
+end
+
+function WeightedChooser:next(random)
+	random = random or math.random
+	local breaks = self._breaks
+	local value = random() * breaks[#breaks]
+	return self._elements[futil.bisect.right(breaks, value)]
+end
+
+futil.random.WeightedChooser = WeightedChooser
+
+function futil.random.choice(t, random)
+	assert(#t > 0, "cannot get choice from an empty table")
+	random = random or math.random
+	return t[random(#t)]
+end
+
+-- https://stats.stackexchange.com/questions/569647/
+function futil.random.sample(t, k, random)
+	assert(k <= #t, f("cannot sample %i items from a set of size %i", k, #t))
+	random = random or math.random
+	local sample = {}
+	for i = 1, k do
+		sample[i] = t[i]
+	end
+	for j = k + 1, #t do
+		if random() < k / j then
+			sample[random(1, k)] = t[j]
+		end
+	end
+
+	return sample
+end
+
+function futil.random.sample_with_indices(t, k, random)
+	assert(k <= #t, f("cannot sample %i items from a set of size %i", k, #t))
+	random = random or math.random
+	local sample = {}
+	for i = 1, k do
+		sample[i] = { i, t[i] }
+	end
+	for j = k + 1, #t do
+		if random() < k / j then
+			sample[random(1, k)] = { j, t[j] }
+		end
+	end
+
+	return sample
+end