대화형 모드의 진법(radix) 변환 예제 with Go

다음은  대화형 모드(interactive mode)에서 진법 변환(radix conversion)하는 Go 언어 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 변환을 하는 핵심 함수 convertAtoI()와 convertItoA()의 소스가 자체 제작되어 포함되어 있다. 이를 이용하는 부분은 152~153째 줄에 있는 

         val = convertAtoI(s, srcRdx) 
         ret = convertItoA(val, destRdx)

이다. 지원되는 진법은 2진법에서 36진법 까지이다.
    

1. /*
2.  *  Filename: convertRadix.go
3.  *
4.  *            Convert radix in a interactive mode.
5.  *
6.  *  Execute: go run convertRadix.go
7.  *
8.  *  or
9.  *
10.  *  Compile: go build convertRadix.go
11.  *  Execute: ./convertRadix
12.  *
13.  *      Date:  2012/06/25
14.  *    Author:  PH Kim   [ pkim (AT) scripts.pe.kr ]
15.  */
17. package main
19. import (
20.     "fmt"
21.     "bufio"
22.     "os"
23.     "strings"
24. )   
26. type _TOKEN struct {
27.     a string
28.     b string
29. }
31. func println(s string) {
32.     fmt.Printf("%s\n", s)
33. }
35. func print(s string) { 
36.     fmt.Printf("%s", s)
37. }
39. func printUsage() {
40.     println("Usage: convertRadix")
41.     println("Convert radix in an interactive mode, where the maximum radix is 36.")
42. }
44. func printAbout() {
45.     println("    About: Convert radix in a interactive mode.")
46. }
48. func printMainMenu() {
49.     println("  Command: (S)etup radix, (A)bout, (Q)uit or E(x)it")
50. }
52. func printMainPrompt() {
53.     print("  Prompt> ")
54. }
56. func printSubMenu(srcRadix int, destRadix int) {
57.     var sbuf string
58.     fmt.Sprintf(sbuf, "    Convert Radix_%d to Radix_%d", srcRadix, destRadix);
59.     println(sbuf);
60.     println("    SubCommand: 'main()' to goto Main menu, 'exit()' or 'quit()' to exit");
61. }
63. func printSubPrompt() {
64.     print("    Input Value>> ");
65. }
67. func convertItoA(num int64, radix int) (ret string) {
68.     var BASE36 = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
69.     var tmp string
70.     var arr string
71.     var q, r int64
72.     var i, n int
73.     var isNegative bool = false
75.     if num < 0 {
76.         isNegative = true
77.         num = -num
78.     }
80.     arr = ""
81.     q = num
82.     r = 0
84.     for q >= int64(radix) {
85.         r = q % int64(radix)
86.         q = q / int64(radix)
87.         tmp = BASE36[r:r+1]
88.         arr += tmp
89.     }
91.     tmp = BASE36[q:q+1]
92.     arr += tmp
93.     if isNegative {
94.         arr += "-"
95.     }
97.     n = len(arr)
98.     for i = 0; i < n; i++ {
99.         ret += arr[n - i - 1:n-i]
100.     }
101.     return ret
102. }
104. func convertAtoI(str string, radix int) (ret int64) {
105.     var isNegative bool = false
106.     var len int = len(str)
107.     var c byte
108.     var i int
109.     var val int64
111.     c = str[0]
112.     if c == '-' {
113.         isNegative = true
114.     } else if c >= '0' && c <= '9' {
115.         ret = int64(c) - int64('0')
116.     } else if c >= 'A' && c <= 'Z' {
117.         ret = int64(c - 'A') + 10
118.     } else if c >= 'a' && c <= 'z' {
119.         ret = int64(c - 'a') + 10
120.     }
121.     if ret >= int64(radix) {
122.         println("        Invalid character!")
123.         return ret
124.     }
126.     for i = 1; i < len; i++ {
127.         c = str[i]
128.         ret *= int64(radix)
129.         if c >= '0' && c <= '9' {
130.             val = int64(c - '0')
131.         } else if c >= 'A' && c <= 'Z' {
132.             val = int64(c - 'A') + 10
133.         } else if c >= 'a' && c <= 'z' {
134.             val = int64(c - 'a') + 10
135.         }
136.         if val >= int64(radix) {
137.             println("        Invalid character!")
138.             return ret
139.         }
140.         ret += val
141.     }
143.     if isNegative {
144.         ret = -ret
145.     }
147.     return ret
148. }
150. func convertRadix(s string, srcRdx  int, destRdx int) (ret string) {
151.     var val int64
152.     val = convertAtoI(s, srcRdx)
153.     ret = convertItoA(val, destRdx)
154.     return ret
155. }
157. func readLine() (data string) {
158.     fmt.Scanf(data, "%s") //
159.     return data
160. }
162. func readTwo() (token _TOKEN) { 
163.     token.a = ""
164.     token.b = ""
165.     fmt.Scanf("%s %s", &token.a, &token.b)    // call twice, is It a bug?
166.     fmt.Scanf("%s %s", &token.a, &token.b)    // call twice, is It a bug?
167.     return token
168. }
170. func tokenize(ptoken _TOKEN, line string, c byte) {
171.     var i int
172.     var from, to int
174.     i = 0
175.     for line[i] != c {
176.         i += 1
177.     }
178.     from = i
179.     for line[i] == c {
180.         i += 1
181.     }
182.     to = i
183.     ptoken.a = line[0: to - from]
185.     for line[i] != c {
186.         i += 1
187.     }
188.     from = i
189.     for line[i] == c {
190.         i += 1
191.     }
192.     to = i
193.     ptoken.b = line[0: to - from]
194. }
196. func doConvert(srcRadix int,destRadix int) {
197.     var sbuf string
198.     var cmd string
199.     var srcStr string
200.     var destStr string
202.     println("")
203.     printSubMenu(srcRadix, destRadix)
205.     for {
206.         printSubPrompt()
207.         cmd = ""
208.         fmt.Scanf("%s", &cmd)        // call twice, is It a bug?
209.         for cmd == "" {
210.             fmt.Scanf("%s", &cmd)       // call twice, is It a bug?
211.         }
212.         if cmd == "main()" {
213.             return
214.         } else if cmd == "exit()" || cmd == "quit()" {
215.             os.Exit(0)
216.         } '
218.         srcStr = cmd
219.         destStr = convertRadix(srcStr, srcRadix, destRadix)
220.         sbuf = fmt.Sprintf("        ( %s )_%d   --->   ( %s )_%d", srcStr, srcRadix, destStr, destRadix);
221.         println(sbuf)
222.         println("")
223.     }
224. }
226. func doStart() { 
227.     var srcRadix int = 10
228.     var destRadix int = 10 
229.     var st _TOKEN
230.     var onlyOnce bool = true
232.     for {
233.         println("")
234.         if onlyOnce {
235.             println("  The supported maximum radix is 36.")
236.             onlyOnce = false
237.         }
239.         printMainMenu()
240.         printMainPrompt()
241.         var cmd string = ""
242.         fmt.Scanf("%s", &cmd)    // call twice, is It a bug?
243.         fmt.Scanf("%s", &cmd)    // call twice, is It a bug?
245.         if  len(cmd) == 1&& strings.IndexAny("qQxX", cmd) >= 0 {
246.             os.Exit(0)
247.         }  else if len(cmd) == 1&& strings.IndexAny("aA", cmd) >= 0 {
248.             printAbout()
249.         }  else if len(cmd) == 1&& strings.IndexAny("sS", cmd) >= 0 {
250.             print("  Input the source and target radices (say, 16 2): ") 
251.             st = readTwo()
252.             srcRadix = int(convertAtoI(st.a, 10))
253.             destRadix = int(convertAtoI(st.b, 10))
254.             doConvert(srcRadix, destRadix)
255.         }
256.     }
257. }
259. func waitCommand(str string) string {
260.         print(str)
261.         reader := bufio.NewReader(os.Stdin)
262.         input, _ := reader.ReadString('\n')
263.         if len(input) > 0 && input[len(input) -1] == '\n' {
264.             input = input[0:len(input) -1]
265.         }
266.         if len(input) > 0 && input[len(input) -1] == '\r' {
267.             input = input[0:len(input) -1]
268.         }
269.         return input
270. }
272. func main() {
273.     if len(os.Args) > 1 &&  os.Args[1] == "-h" {
274.         printUsage()
275.         return
276.     }
277.     doStart()
278. }

실행> go run convertRadix.go

또는

컴파일> go build convertRadix.go
실행> ./convertRadix

  The supported maximum radix is 36.
  Command: (S)etup radix, (A)bout, (Q)uit or E(x)it
  Prompt> s
  Input the source and target radices (say, 16 2): 8 16

    Convert Radix_8 to Radix_16
    SubCommand: 'main()' to goto Main menu, 'exit()' or 'quit()' to exit
    Input Value>> 1234
        ( 1234 )_8   --->   ( 29C )_16

    Input Value>> main()

  Command: (S)etup radix, (A)bout, (Q)uit or E(x)it
  Prompt> s
  Input the source and target radices (say, 16 2): 16 8

    Convert Radix_16 to Radix_8
    SubCommand: 'main()' to goto Main menu, 'exit()' or 'quit()' to exit
    Input Value>> 29c
        ( 29c )_16   --->   ( 1234 )_8

    Input Value>> exit()