Added Support For Indian Numbering System (#37)

Author: beingmohit

README.md

@@ -44,6 +44,7 @@ Currently supported languages are:
 - French `lang = "fr"`
 - Esperanto `lang = "eo"`
 - Vietnamese `lang = "vi"`
+- English (Indian) `lang = "enIndian"`
 
 ### Spanish Example
 ```javascript

lib/i18n/en-indian.json

@@ -0,0 +1,42 @@
+{
+  "useLongScale": false,
+  "baseSeparator": "-",
+  "unitSeparator": "and ",
+  "base": {
+    "0": "zero",
+    "1": "one",
+    "2": "two",
+    "3": "three",
+    "4": "four",
+    "5": "five",
+    "6": "six",
+    "7": "seven",
+    "8": "eight",
+    "9": "nine",
+    "10": "ten",
+    "11": "eleven",
+    "12": "twelve",
+    "13": "thirteen",
+    "14": "fourteen",
+    "15": "fifteen",
+    "16": "sixteen",
+    "17": "seventeen",
+    "18": "eighteen",
+    "19": "nineteen",
+    "20": "twenty",
+    "30": "thirty",
+    "40": "forty",
+    "50": "fifty",
+    "60": "sixty",
+    "70": "seventy",
+    "80": "eighty",
+    "90": "ninety"
+  },
+  "units" : {
+    "2": "hundred",
+    "3": "thousand",
+    "5": "lakh",
+    "7": "crore"
+  },
+  "unitExceptions": []
+}

lib/index.js

@@ -11,6 +11,7 @@ var i18n = {
   eo: require('./i18n/eo.json'),
   it: require('./i18n/it.json'),
   vi: require('./i18n/vi.json'),
+  enIndian:  require('./i18n/en-indian.json'),
 };
 exports.i18n = i18n;
 
@@ -47,8 +48,28 @@ function writtenNumber(n, options) {
     ? i18n[options.lang]
     : options.lang;
   var scale = language.useLongScale ? longScale : shortScale;
+  var units = language.units;
   var unit;
 
+  
+  
+  if (! (units instanceof Array))
+  {
+    var rawUnits = units;
+    
+    units = [];
+    scale = Object.keys(rawUnits);
+
+    for (var i in scale)
+    {
+      units.push(rawUnits[scale[i]])
+      scale[i] = Math.pow(10, parseInt(scale[i]));
+    }
+  }
+
+  
+  
+  
   if (!language) {
     if (languages.indexOf(writtenNumber.defaults.lang) < 0) {
       writtenNumber.defaults.lang = 'en';
@@ -74,15 +95,18 @@ function writtenNumber(n, options) {
     n -= m;
   } else ret = [];
 
-  for(var i = 0, len = language.units.length; i < len; i++) {
+  for(var i = 0, len = units.length; i < len; i++) {
     var r = Math.floor(n / scale[i]);
-    if(i === 0) {
-      r %= 10;
-    } else if(!language.useLongScale || (i === 1 && language.useLongScale)) {
-      r %= 1000;
-    } else r %= 1000000;
+  
+    if (i == len - 1)
+      var divideBy = 1000000;
+    else 
+      var divideBy = scale[i+1] / scale[i];
+      
+    r %= divideBy;
+
+    unit = units[i];
 
-    unit = language.units[i];
     if(r && unit.useBaseInstead) {
       if(unit.useBaseException.indexOf(r) < 0) {
         ret.push(baseCardinals[r * scale[i]]);
@@ -126,3 +150,4 @@ function handleSmallerThan100(n, language, unit, baseCardinals, options) {
   }
   return baseCardinals[dec];
 }
+

test/index.test.js

@@ -321,4 +321,82 @@ describe('written-number', function() {
       );
     });
   });
+  
+  describe('writtenNumber(n, { lang: \'enIndian\', ... })', function() {
+    before(function() {
+      writtenNumber.defaults.lang = 'enIndian';
+    });
+
+    it('gets exposed', function() {
+      should.exist(writtenNumber);
+      writtenNumber.should.be.instanceof(Function);
+    });
+
+    it('doesn\'t blow up weirdly with invalid input', function() {
+      writtenNumber('asdfasdfasdf').should.equal('');
+      writtenNumber('0.as').should.equal('');
+      writtenNumber('0.123').should.equal('zero');
+      writtenNumber('0.8').should.equal('one');
+      writtenNumber('2.8').should.equal('three');
+      writtenNumber('asdf.8').should.equal('');
+      writtenNumber('120391938123..').should.equal('');
+      writtenNumber(1000000000).should.equal('one hundred crore');
+      writtenNumber('1/3').should.equal('');
+      writtenNumber(1/3).should.equal('zero');
+      writtenNumber('1/2').should.equal('');
+      writtenNumber('1.123/2').should.equal('');
+    });
+
+    it('correctly converts numbers < 10', function() {
+      writtenNumber(1000000000).should.equal('one hundred crore');
+      writtenNumber(3).should.equal('three');
+      writtenNumber(8).should.equal('eight');
+    });
+
+    it('correctly converts numbers < 20', function() {
+      writtenNumber(13).should.equal('thirteen');
+      writtenNumber(19).should.equal('nineteen');
+    });
+
+    it('correctly converts numbers < 100', function() {
+      writtenNumber(20).should.equal('twenty');
+      writtenNumber(25).should.equal('twenty-five');
+      writtenNumber(88).should.equal('eighty-eight');
+      writtenNumber(73).should.equal('seventy-three');
+    });
+
+    it('correctly converts numbers < 1000', function() {
+      writtenNumber(200).should.equal('two hundred');
+      writtenNumber(242).should.equal('two hundred and forty-two');
+      writtenNumber(1234).should.equal(
+        'one thousand two hundred and thirty-four'
+      );
+      writtenNumber(4323).should.equal(
+        'four thousand three hundred and twenty-three'
+      );
+    });
+
+    it('correctly converts numbers > 1000', function() {
+      writtenNumber(4323000).should.equal(
+        'forty-three lakh twenty-three thousand'
+      );
+      writtenNumber(4323055).should.equal(
+          'forty-three lakh twenty-three thousand and fifty-five'
+        );
+      writtenNumber(1570025).should.equal(
+        'fifteen lakh seventy thousand and twenty-five'
+      );
+    });
+
+    it('correctly converts numbers > 1 000 000 000', function() {
+      writtenNumber(1000000000).should.equal('one hundred crore');
+      writtenNumber(2580000000).should.equal(
+        'two hundred fifty-eight crore'
+      );
+      writtenNumber(1000000000000).should.equal('one lakh crore');
+      writtenNumber(3627000000000).should.equal(
+        'three lakh sixty-two thousand seven hundred crore'
+      );
+    });
+  });
 });