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750 | daniel-mar | 1 | |
2 | /** |
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3 | * WEID<=>OID Converter |
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4 | * (c) Webfan.de, ViaThinkSoft |
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5 | * Revision 2022-02-22 |
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6 | **/ |
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7 | |||
8 | // What is a WEID? |
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9 | // A WEID (WEhowski IDentifier) is an alternative representation of an |
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10 | // OID (Object IDentifier) defined by Till Wehowski. |
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11 | // In OIDs, arcs are in decimal base 10. In WEIDs, the arcs are in base 36. |
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12 | // Also, each WEID has a check digit at the end (called WeLohn Check Digit). |
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13 | // |
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14 | // Changes in the December 2021 definition by Daniel Marschall: |
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15 | // - There are several classes of WEIDs which have different OID bases: |
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16 | // "Class C" WEID: weid:EXAMPLE-3 (base .1.3.6.1.4.1.37553.8.) |
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17 | // oid:1.3.6.1.4.1.37553.8.32488192274 |
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18 | // "Class B" WEID: weid:pen:SX0-7PR-6 (base .1.3.6.1.4.1.) |
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19 | // oid:1.3.6.1.4.1.37476.9999 |
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20 | // "Class A" WEID: weid:root:2-RR-2 (base .) |
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21 | // oid:2.999 |
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22 | // - The namespace (weid:, weid:pen:, weid:root:) is now case insensitive. |
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23 | // - Padding with '0' characters is valid (e.g. weid:000EXAMPLE-3) |
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24 | // The paddings do not count into the WeLuhn check-digit. |
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25 | |||
26 | var WeidOidConverter = { |
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27 | |||
28 | weLuhnCheckDigit: function(str) { |
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29 | // Padding zeros don't count to the check digit (December 2021) |
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30 | var ary = str.split('-'); |
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31 | ary.forEach((o,i,a) => { |
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32 | a[i] = a[i].replace(/^0+/, ''); |
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33 | } ); |
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34 | str = ary.join('-'); |
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35 | |||
36 | // remove separators from the WEID string |
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37 | var wrkstr = str.replaceAll('-', ''); |
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38 | |||
39 | // Replace 'a' with '10', 'b' with '1', etc. |
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40 | for (var i=0; i<26; i++) { |
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41 | wrkstr = wrkstr.toLowerCase().replaceAll(String.fromCharCode('a'.charCodeAt(0)+i).toLowerCase(), (10+i)); |
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42 | } |
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43 | |||
44 | // At the end, wrkstr should only contain digits! Verify it! |
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751 | daniel-mar | 45 | if (!wrkstr.match(/^\d+$/)) { |
46 | console.error("weLuhnCheckDigit: Invalid input"); |
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47 | return false; |
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48 | } |
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750 | daniel-mar | 49 | |
50 | // Now do the standard Luhn algorithm |
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51 | var nbdigits = wrkstr.length; |
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52 | var parity = nbdigits & 1; // mod 2 |
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53 | var sum = 0; |
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54 | for (var n=nbdigits-1; n>=0; n--) { |
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55 | var digit = parseInt(wrkstr.substr(n,1)); |
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56 | if ((n & 1) != parity) digit *= 2; |
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57 | if (digit > 9) digit -= 9; |
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58 | sum += digit; |
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59 | } |
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60 | return (sum%10) == 0 ? 0 : 10-(sum%10); |
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61 | }, |
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62 | |||
63 | // Translates a WEID to an OID |
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64 | // "weid:EXAMPLE-3" becomes "1.3.6.1.4.1.37553.8.32488192274" |
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65 | // If it failed (e.g. wrong namespace, wrong checksum, etc.) then false is returned. |
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66 | // If the weid ends with '?', the checksum will be added |
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67 | // Return value is an array with the elements "oid" and "weid". |
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68 | // Example: |
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69 | // weid2oid("weid:EXAMPLE-?").weid == "weid:EXAMPLE-3" |
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70 | // weid2oid("weid:EXAMPLE-?").oid == "1.3.6.1.4.1.37553.8.32488192274" |
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71 | weid2oid: function(weid) { |
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72 | var p = weid.lastIndexOf(':'); |
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73 | var namespace = weid.substr(0, p+1); |
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74 | var rest = weid.substr(p+1); |
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75 | |||
76 | namespace = namespace.toLowerCase(); // namespace is case insensitive |
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77 | if (namespace == 'weid:') { |
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78 | // Class C |
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79 | var base = '1-3-6-1-4-1-SZ5-8'; |
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80 | } else if (namespace == 'weid:pen:') { |
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81 | // Class B |
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82 | var base = '1-3-6-1-4-1'; |
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83 | } else if (namespace == 'weid:root:') { |
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84 | // Class A |
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85 | var base = ''; |
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86 | } else { |
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87 | // Wrong namespace |
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751 | daniel-mar | 88 | console.error("weid2oid: Wrong input"); |
750 | daniel-mar | 89 | return false; |
90 | } |
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91 | |||
92 | weid = rest; |
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93 | |||
94 | var elements = ((base != '') ? base.split('-') : []).concat(weid.split('-')); |
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95 | var actual_checksum = elements.pop(); |
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751 | daniel-mar | 96 | var expected_checksum = WeidOidConverter.weLuhnCheckDigit(elements.join('-')); |
750 | daniel-mar | 97 | if (actual_checksum != '?') { |
751 | daniel-mar | 98 | if (actual_checksum != expected_checksum) { |
99 | console.error("weid2oid: Wrong checksum"); |
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100 | return false; // wrong checksum |
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101 | } |
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750 | daniel-mar | 102 | } else { |
103 | // If checksum is '?', it will be replaced by the actual checksum, |
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104 | // e.g. weid:EXAMPLE-? becomes weid:EXAMPLE-3 |
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105 | weid = weid.replace('?', expected_checksum); |
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106 | } |
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107 | elements.forEach((o,i,a) => { |
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751 | daniel-mar | 108 | a[i] = WeidOidConverter.base_convert_bigint(a[i], 36, 10); |
750 | daniel-mar | 109 | }); |
110 | var oidstr = elements.join('.'); |
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111 | |||
112 | weid = namespace.toLowerCase() + weid.toUpperCase(); // add namespace again |
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113 | |||
114 | return { "weid": weid, "oid" : oidstr }; |
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115 | }, |
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116 | |||
117 | // Converts an OID to WEID |
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118 | // "1.3.6.1.4.1.37553.8.32488192274" becomes "weid:EXAMPLE-3" |
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119 | oid2weid: function(oid) { |
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120 | if (oid.substr(0,1) == '.') oid = oid.substr(1); // remove leading dot |
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121 | |||
122 | if (oid != '') { |
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123 | var elements = oid.split('.'); |
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751 | daniel-mar | 124 | elements.forEach((o,i,a) => { |
125 | a[i] = WeidOidConverter.base_convert_bigint(a[i], 10, 36); |
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750 | daniel-mar | 126 | }); |
127 | var weidstr = elements.join("-"); |
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128 | } else { |
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129 | var weidstr = ''; |
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130 | } |
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131 | |||
132 | var is_class_c = (weidstr.startsWith('1-3-6-1-4-1-SZ5-8-') || (weidstr == '1-3-6-1-4-1-SZ5-8')); |
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133 | var is_class_b = (weidstr.startsWith('1-3-6-1-4-1-') || (weidstr == '1-3-6-1-4-1')); |
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134 | var is_class_a = !is_class_b && !is_class_c; |
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135 | |||
751 | daniel-mar | 136 | var checksum = WeidOidConverter.weLuhnCheckDigit(weidstr); |
750 | daniel-mar | 137 | |
138 | if (is_class_c) { |
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139 | weidstr = weidstr.substr('1-3-6-1-4-1-SZ5-8-'.length); |
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140 | var namespace = 'weid:'; |
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141 | } else if (is_class_b) { |
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142 | weidstr = weidstr.substr('1-3-6-1-4-1-'.length); |
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143 | var namespace = 'weid:pen:'; |
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144 | } else if (is_class_a) { |
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145 | // weidstr stays |
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146 | var namespace = 'weid:root:'; |
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147 | } else { |
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148 | // should not happen |
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149 | console.error("oid2weid: Cannot detect namespace"); |
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150 | return false; |
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151 | } |
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152 | |||
751 | daniel-mar | 153 | return { "weid": namespace + (weidstr == '' ? checksum : weidstr + '-' + checksum), "oid": oid }; |
154 | }, |
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155 | |||
156 | base_convert_bigint: function(numstring, frombase, tobase) { |
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157 | |||
752 | daniel-mar | 158 | // This variant would require the "mikemcl/bignumber.js" library: |
751 | daniel-mar | 159 | //var x = BigNumber(numstr, frombase); |
752 | daniel-mar | 160 | //return isNaN(x) ? false : x.toString(tobase).toUpperCase(); |
751 | daniel-mar | 161 | |
162 | var frombase_str = ''; |
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163 | for (var i=0; i<frombase; i++) { |
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164 | frombase_str += parseInt(i, 10).toString(36).toUpperCase(); |
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165 | } |
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166 | |||
167 | var tobase_str = ''; |
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168 | for (var i=0; i<tobase; i++) { |
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169 | tobase_str += parseInt(i, 10).toString(36).toUpperCase(); |
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170 | } |
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171 | |||
752 | daniel-mar | 172 | for (var i=0; i<numstring.length; i++) { |
173 | if (frombase_str.toLowerCase().indexOf(numstring.substr(i,1).toLowerCase()) < 0) { |
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174 | console.error("base_convert_bigint: Invalid input"); |
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175 | return false; |
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176 | } |
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177 | } |
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178 | |||
179 | var length = numstring.length; |
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751 | daniel-mar | 180 | var result = ''; |
181 | var number = []; |
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182 | for (var i=0; i<length; i++) { |
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183 | number[i] = frombase_str.toLowerCase().indexOf(numstring[i].toLowerCase()); |
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184 | } |
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185 | do { // Loop until whole number is converted |
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186 | var divide = 0; |
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187 | var newlen = 0; |
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188 | for (var i=0; i<length; i++) { // Perform division manually (which is why this works with big numbers) |
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189 | divide = divide * frombase + parseInt(number[i]); |
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190 | if (divide >= tobase) { |
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191 | number[newlen++] = (divide / tobase); |
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192 | divide = divide % tobase; |
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193 | } else if (newlen > 0) { |
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194 | number[newlen++] = 0; |
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195 | } |
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196 | } |
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197 | length = newlen; |
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198 | result = tobase_str.substr(divide,1) + result; // Divide is basically numstring % tobase (i.e. the new character) |
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199 | } |
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200 | while (newlen != 0); |
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201 | |||
202 | return result; |
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750 | daniel-mar | 203 | } |
204 | } |