대화형 모드의 진법(radix) 변환 예제 with Lua

다음은  대화형 모드(interactive mode)에서 진법 변환(radix conversion)하는 Lua 소스 코드이다.
메뉴는 주메뉴 Command: (S)et radix, (A)bout, (Q)uit or E(x)it
와 부메뉴 SubCommand: 'main()' to goto Main menu, 'exit()' or 'quit()' to exit
로 구성되어 있으며, 진법 변환의 핵심은 Lua 의 빌트인 함수 tonumber(string, radix)와 소스 코드에 자체 작성된 함수 itoa(number, radix)의 사용이다.

         val = tonumber(s, srcRdx)
         ret = itoa(val, destRdx)

지원되는 진법은 2진법에서 36진법 까지이다.

1. --  Filename: convertRadix.lua
2. --            Convert radix in a interactive mode.
3. --
4. --   Execute: lua convertRadix.lua
5. --
6. --      Date:  2008/03/26
7. --    Author:  PH Kim   [ pkim (AT) scripts.pe.kr ]
9. function println(s)
10.     if s ~= nil then
11.         print(s)
12.     else
13.         print("")
14.     end
15. end
17. function printUsage()
18.     println("Usage: lua convertRadix.lua")
19.     println("Convert radix in a interactive mode, where the maximum radix is 36.")
20. end
22. function printAbout()
23.     println("    About: Convert radix in a interactive mode.")
24. end
26. function printMainMenu()
27.     println("  Command: (S)et radix, (A)bout, (Q)uit or E(x)it")
28. end
30. function printMainPrompt()
31.     io.write("  Prompt> ")
32. end
34. function printSubMenu(srcRadix, destRadix)
35.     println("    Convert Radix_" .. srcRadix .. " to Radix_" .. destRadix)
36.     println("    SubCommand: 'main()' to goto Main menu, 'exit()' or 'quit()' to exit")
37. end
39. function printSubPrompt()
40.     io.write("    Input Value>> ")
41. end
43. local BASE36 = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
45. function itoa(num, radix)
46.    local isNegative = false
47.    if num < 0 then
48.       isNegative = true
49.       num = -num
50.    end
52.    local arr = {}
53.    local q, r = num, 0
54.    while q >= radix do
55.       r = math.fmod(q, radix)
56.       q = math.floor(q / radix)
57.       table.insert(arr, string.sub(BASE36, r+1, r+1))
58.    end
60.    table.insert(arr, string.sub(BASE36, q+1, q+1))
61.    if isNegative then
62.       table.insert(arr, "-")
63.    end
64.    local ret = ""
65.    for i = #arr, 1, -1 do
66.        ret = ret .. arr[i]
67.    end
68.    return ret
69. end
71. function convertRadix(s, srcRdx, destRdx)
72.     local val = tonumber(s, srcRdx)
73.     local ret = itoa(val, destRdx)
74.     return string.upper(ret)
75. end
77. function doConvert(srcRadix, destRadix)
78.     local line = ""
79.     local cmd = ""
80.     local srcStr = ""
81.     local destStr = ""
83.     printSubMenu(srcRadix, destRadix)
84.     while true do
85.         printSubPrompt()
86.         cmd = io.read()
87.         while string.len(cmd) < 1 do
88.             cmd = io.read()
89.         end
91.         if "main()" == cmd then
92.             return
93.         elseif "exit()" == cmd or "quit()" == cmd then
94.             os.exit(0)
95.         end
97.         local flagContinue = true
98.         if tonumber(cmd, srcRadix) == nil then
99.             flagContinue = false
100.         end
101.         if flagContinue then
102.             srcStr = cmd
103.             destStr = convertRadix(srcStr, srcRadix, destRadix)
104.             println("        ( " .. srcStr .. " )_" .. srcRadix .. "   --->   ( " .. destStr .. " )_" .. destRadix)
105.             println("")
106.         end
107.     end
108. end
110. function doStart()
111.     local line = ""
112.     local cmd = ""
113.     local srcRadix = 10
114.     local destRadix = 10
115.     local srcStr = ""
116.     local destStr = ""
117.     local onlyOnce = true
119.     while true do
120.         println()
121.         if onlyOnce then
122.             println("  The supported maximum radix is 36.")
123.             onlyOnce = false
124.         end
126.         printMainMenu()
127.         printMainPrompt()
128.         cmd = io.read()
129.         while string.len(cmd) < 1 do
130.             cmd = io.read()
131.         end
133.         if string.find("qQxX", cmd) ~= nil and string.len(cmd) == 1 then
134.             os.exit(0)
135.         elseif string.find("aA", cmd) ~= nil and string.len(cmd) == 1 then
136.             printAbout()
137.         elseif string.find("sS", cmd) ~= nil and string.len(cmd) == 1 then
138.             io.write("  Input the source and target radices (say, 16 2): ")
139.             line = io.read()
140.             while string.len(line) < 1 do
141.                 line = io.read()
142.             end
144.             st = {}
145.             for w in string.gmatch(line, "[0-9]*") do
146.                 if string.len(w) > 0 then
147.                     table.insert(st, w)
148.                 end
149.             end
151.             while #st < 2 do
152.                 io.write("  Input the source and target radices (say, 16 2): ")
153.                 line = io.read()
154.                while string.len(line) < 1 do
155.                     line = io.read()
156.                 end
158.                 st = {}
159.                 for w in string.gmatch(line, "%a+") do
160.                     if string.len(w) > 0 then
161.                         table.insert(st, w)
162.                     end
163.                 end
164.             end
166.             println("")
167.             srcRadix = tonumber(st[1])
168.             destRadix = tonumber(st[2])
169.             doConvert(srcRadix, destRadix)
170.         end
171.     end
172. end
174. -- Begin here
175. if #arg > 0 and "-h" == arg[1] then
176.     printUsage()
177.     os.exit(1)
178. end
180. doStart()

실행> lua convertRadix.lua

  The supported maximum radix is 36.
  Command: (S)et radix, (A)bout, (Q)uit or E(x)it
  Prompt> s
  Input the source and target radices (say, 16 2): 16 2

    Convert Radix_16 to Radix_2
    SubCommand: 'main()' to goto Main menu, 'exit()' or 'quit()' to exit
    Input Value>> 7F
        ( 7F )_16   --->   ( 1111111 )_2

    Input Value>> main()

  Command: (S)et radix, (A)bout, (Q)uit or E(x)it
  Prompt> S
  Input the source and target radices (say, 16 2): 2 16

    Convert Radix_2 to Radix_16
    SubCommand: 'main()' to goto Main menu, 'exit()' or 'quit()' to exit
    Input Value>> 1111111
        ( 1111111 )_2   --->   ( 7F )_16

    Input Value>> exit()






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