Revision of tree.lua

capitalex revidoval tento gist 1 month ago. Přejít na revizi

1 file changed, 24 insertions

tree.lua

			@@ -62,6 +62,21 @@ local function parse(string)
62	62		return build_tree(string:gmatch("."))
63	63		end
64	64
	65	+	local objects = {}
	66	+	objects.Nowhere = {
	67	+	objects = {},
	68	+	create = function(self, stream)
	69	+	local name = table.concat(stream(), " ")
	70	+	self.objects[name] = {
	71	+	lookAt = function(self, stream)
	72	+	print("You see " .. name)
	73	+	return self
	74	+	end
	75	+	}
	76	+	return self.objects[name]
	77	+	end
	78	+	}
	79	+
65	80		local function reduce(tree)
66	81		if type(tree) ~= "table" then
67	82		return tree
			@@ -78,6 +93,15 @@ local function reduce(tree)
78	93		for node in node_stream do
79	94		if not target then
80	95		target = reduce(node)
	96	+	if objects[target] then
	97	+	target = objects[target]
	98	+	end
	99	+	elseif type(target) == "table" then
	100	+	if target[node] then
	101	+	target = target[node](target, node_stream)
	102	+	else
	103	+	error("Object does not respond to " .. node)
	104	+	end
81	105		elseif type(target) == "number" then
82	106		local next = reduce(node_stream())
83	107		if node == "+" then

capitalex revidoval tento gist 1 month ago. Přejít na revizi

1 file changed, 100 insertions

tree.lua(vytvořil soubor)

		@@ -0,0 +1,100 @@
1	+	local function table_stream(t)
2	+	return coroutine.wrap(function()
3	+	for _, v in ipairs(t) do
4	+	coroutine.yield(v)
5	+	end
6	+	end)
7	+	end
8	+
9	+	local function push(t, v)
10	+	table.insert(t, v)
11	+	end
12	+
13	+	local function show_tree(tree)
14	+	local buffer = {}
15	+	for node in table_stream(tree) do
16	+	if type(node) == "table" then
17	+	local subtree = ("(%s)"):format(show_tree(node))
18	+	push(buffer, subtree)
19	+	else
20	+	push(buffer, tostring(node))
21	+	end
22	+	end
23	+	return table.concat(buffer, " ")
24	+	end
25	+
26	+
27	+	local function build_symbol(bits)
28	+	local symbol = table.concat(bits)
29	+	if tonumber(symbol) then return tonumber(symbol)
30	+	elseif symbol == "true" then return true
31	+	elseif symbol == "false" then return false
32	+	else return symbol
33	+	end
34	+	end
35	+
36	+	local function build_tree(stream)
37	+	local tree = {}
38	+	local symbol = {}
39	+	for char in stream do
40	+	if char == "(" then
41	+	push(tree, build_tree(stream))
42	+	elseif char == ")" then
43	+	break
44	+	elseif char == " " and #symbol ~= 0 then
45	+	push(tree, build_symbol(symbol))
46	+	symbol = {}
47	+	elseif char:match("%s") then
48	+	-- no op
49	+	else
50	+	push(symbol, char)
51	+	end
52	+	end
53	+
54	+	if #symbol ~= 0 then
55	+	push(tree, build_symbol(symbol))
56	+	end
57	+
58	+	return tree
59	+	end
60	+
61	+	local function parse(string)
62	+	return build_tree(string:gmatch("."))
63	+	end
64	+
65	+	local function reduce(tree)
66	+	if type(tree) ~= "table" then
67	+	return tree
68	+	end
69	+
70	+	local index = 1
71	+	local target = nil
72	+	local node_stream = coroutine.wrap(function()
73	+	for _, node in ipairs(tree) do
74	+	coroutine.yield(node)
75	+	end
76	+	end)
77	+
78	+	for node in node_stream do
79	+	if not target then
80	+	target = reduce(node)
81	+	elseif type(target) == "number" then
82	+	local next = reduce(node_stream())
83	+	if node == "+" then
84	+	target = target + next
85	+	elseif node == "-" then
86	+	target = target - next
87	+	elseif node == "*" then
88	+	target = target * next
89	+	elseif node == "/" then
90	+	target = target / next
91	+	else
92	+	error("Object does not respond to " .. node)
93	+	end
94	+	end
95	+	end
96	+	return target
97	+	end
98	+
99	+	print(show_tree(parse(arg[1])))
100	+	print(reduce(parse(arg[1])))

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