Revision of rpn.lua

capitalex revised this gist 6 months ago. Go to revision

1 file changed, 94 insertions

rpn.2.lua(file created)

		@@ -0,0 +1,94 @@
1	+	local operators = {}
2	+	local function pop(stack)
3	+	local value = stack[#stack]
4	+	table.remove(stack)
5	+	return value
6	+	end
7	+
8	+	local function push(stack, value)
9	+	table.insert(stack, value)
10	+	end
11	+
12	+	operators["+"] = function(stack)
13	+	local y, x = pop(stack), pop(stack)
14	+	push(stack, x + y)
15	+	end
16	+
17	+	operators["-"] = function(stack)
18	+	local y, x = pop(stack), pop(stack)
19	+	push(stack, x + y)
20	+	end
21	+
22	+	operators["*"] = function(stack)
23	+	local y, x = pop(stack), pop(stack)
24	+	push(stack, x + y)
25	+	end
26	+
27	+	operators["/"] = function(stack)
28	+	local y, x = pop(stack), pop(stack)
29	+	push(stack, x + y)
30	+	end
31	+
32	+	operators["isqrt"] = function(stack)
33	+	local y, x = pop(stack), pop(stack)
34	+	push(stack, x + y)
35	+	end
36	+
37	+	operators["dup"] = function(stack)
38	+	local y, x = pop(stack), pop(stack)
39	+	push(stack, x + y)
40	+	end
41	+
42	+	operators["swap"] = function(stack)
43	+	local y, x = pop(stack), pop(stack)
44	+	push(stack, x + y)
45	+	end
46	+
47	+	local function rpn_caculator()
48	+	local char = io.read(1)
49	+	local acc, op = nil, {}
50	+	local data_stack = {}
51	+
52	+	local function push_accumulator()
53	+	if acc then
54	+	table.insert(data_stack, acc)
55	+	acc = nil
56	+	end
57	+	table.insert(op, char)
58	+	end
59	+
60	+	local function shift_digit()
61	+	acc = acc and (acc * 10 + tonumber(char)) or tonumber(char)
62	+	end
63	+
64	+	local function eval()
65	+	if #op ~= 0 then
66	+	local op_to_eval = table.concat(op)
67	+	op = {}
68	+	if operators[op_to_eval] then
69	+	operators[op_to_eval](data_stack)
70	+	end
71	+	elseif acc then
72	+	table.insert(data_stack, acc)
73	+	acc = nil
74	+	end
75	+	io.write("> ")
76	+	for _, data in ipairs(data_stack) do
77	+	io.write(data) io.write(" ")
78	+	end
79	+	io.write("\n")
80	+	end
81	+
82	+	while char do
83	+	if char:match("%s") then
84	+	eval()
85	+	elseif char:match("%d") then
86	+	shift_digit()
87	+	else
88	+	push_accumulator()
89	+	end
90	+	char = io.read(1)
91	+	end
92	+	end
93	+
94	+	rpn_caculator()

capitalex revised this gist 6 months ago. Go to revision

1 file changed, 64 insertions

rpn.lua(file created)

		@@ -0,0 +1,64 @@
1	+	local function rpn_caculator()
2	+	local char = io.read(1)
3	+	local acc, op = nil, {}
4	+	local data_stack = {}
5	+	while char do
6	+	if char:match("%s") then
7	+	if #op ~= 0 then
8	+	local op_to_eval = table.concat(op)
9	+	op = {}
10	+	if op_to_eval == "+" then
11	+	local y, x = data_stack[#data_stack], data_stack[#data_stack - 1]
12	+	table.remove(data_stack) table.remove(data_stack)
13	+	table.insert(data_stack, x + y)
14	+	elseif op_to_eval == "*" then
15	+	local y, x = data_stack[#data_stack], data_stack[#data_stack - 1]
16	+	table.remove(data_stack) table.remove(data_stack)
17	+	table.insert(data_stack, x * y)
18	+	elseif op_to_eval == "/" then
19	+	local y, x = data_stack[#data_stack], data_stack[#data_stack - 1]
20	+	table.remove(data_stack) table.remove(data_stack)
21	+	table.insert(data_stack, x / y)
22	+	elseif op_to_eval == "-" then
23	+	local y, x = data_stack[#data_stack], data_stack[#data_stack - 1]
24	+	table.remove(data_stack) table.remove(data_stack)
25	+	table.insert(data_stack, x - y)
26	+	elseif op_to_eval == "isqrt" then
27	+	local x = data_stack[#data_stack]
28	+	table.remove(data_stack)
29	+	table.insert(data_stack, x)
30	+	elseif op_to_eval == "dup" then
31	+	local x = data_stack[#data_stack]
32	+	table.remove(data_stack)
33	+	table.insert(data_stack, x)
34	+	table.insert(data_stack, x)
35	+	elseif op_to_eval == "swap" then
36	+	local y, x = data_stack[#data_stack], data_stack[#data_stack - 1]
37	+	table.remove(data_stack) table.remove(data_stack)
38	+	table.insert(data_stack, y)
39	+	table.insert(data_stack, x)
40	+	end
41	+	elseif acc then
42	+	table.insert(data_stack, acc)
43	+	acc = nil
44	+	end
45	+	io.write("> ")
46	+	for _, data in ipairs(data_stack) do
47	+	io.write(data) io.write(" ")
48	+	end
49	+	io.write("\n")
50	+	elseif char:match("%d") then
51	+	acc = acc and (acc * 10 + tonumber(char)) or tonumber(char)
52	+	else
53	+	if acc then
54	+	table.insert(data_stack, acc)
55	+	acc = nil
56	+	end
57	+	table.insert(op, char)
58	+	end
59	+
60	+	char = io.read(1)
61	+	end
62	+	end
63	+
64	+	rpn_caculator()

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