version bump to 0.1.1

units.convert now accepts a string for conversion rather than parameters,
the unit types are now determined rather than needed to be given,
the plurarl forms of units are now accepted,
numerizer was added to accept values such as 'forty two',
fixed some incorrect units in default unit db,
update README, added some simple examples

README.md

@@ -15,7 +15,7 @@ npm install node-units
 * `importDB(file_name, cb)` - imports a custom unit database, `cb` takes a single argument `err`
 * `importDBSync(file_name)` - the sync version of `importDB`
 * `getDB()` - returns he currently used database of units as an object
-* `convert(type, value, from, to)` - converts `value` of `from` to `to`, returns the result or raises exception if conversion cannot be made
+* `convert(conversion_string)` - where `conversion_string` is of the form `<value> <from_unit> to <to_unit>`
 
 ### Properties
 * `types` - `types` is an object containing constants for each unit group.
@@ -31,10 +31,10 @@ npm install node-units
 ```javascript
 var units = require('node-units');
 
-var result = units.convert('volume', 5, 'gill', 'mL');
+var result = units.convert('5 gills to mL');
 // result == 591.4705
 
-units.convert(units.types.TIME, 5, 'day', 'second');
+units.convert('five days to seconds');
 ```
 
 ### Custom Units
@@ -42,9 +42,9 @@ units.convert(units.types.TIME, 5, 'day', 'second');
 With `node-units` you can import custom unit definitions from files defined like the following:
 ```
 group:
-  long_name,longname,ln    1ln
-  another_unit,au          5ln
-  one_more,om              2au
+  longname,longname,ln    1ln
+  anotherunit,au          5ln
+  onemore,om              2au
 ```
 
 ```javascript
@@ -52,7 +52,7 @@ var units = require('node-units');
 
 units.importDBSync('my_custom.units');
 
-var result = units.convert(units.types.GROUP, 5, 'au', 'one_more');
+var result = units.convert('five au to onemores');
 // result == 10
 ```
 
@@ -68,7 +68,7 @@ var units = require('node-units');
 
 units.importDBSync('my_custom.units');
 
-var result = units.convert('time', 5, 'minute', 's');
+var result = units.convert('5 minutes to s');
 // result == 250
 ```
 

examples/custom/index.js

@@ -0,0 +1,10 @@
+var path = require('path');
+var units = require('../../');
+
+var db = path.join(path.dirname(module.filename), 'my_custom.units');
+units.importDBSync(db);
+
+console.log(units.convert('5 buttons to widgets'));
+
+
+console.log(units.convert('30 jings to jong'));

examples/custom/my_custom.units

@@ -0,0 +1,9 @@
+elements:
+  button,btn		5wg
+  widget,wg		2tbl
+  table,tbl		1tbl
+
+things:
+  jing			2jabber
+  jabber		30jong
+  jong			1jong

examples/simple/index.js

@@ -0,0 +1,13 @@
+var units = require('../../');
+
+var result = units.convert('20 quarts to gallons');
+
+console.log(result === 5);
+
+
+try{
+    var value = units.convert('5 days to gallon');
+    console.log(value);
+} catch(e){
+    console.log(e);
+}

lib/default.units

@@ -7,9 +7,9 @@ time:
 volume:
   liter,L		1L
   milliliter,mL		0.001L
-  gallon,gal		3.78541L
-  pint			0.473176L
-  quart,qt		0.946353L
+  gallon,gal		8pint
+  pint			0.125gal
+  quart,qt		2pint
   tablespoon,tbl	0.03125pint
   teaspoon,tsp		0.33333333333tbl
   cup			16tbl

lib/index.js

@@ -1,11 +1,16 @@
 var path = require('path');
 var fs = require('fs');
+var numerizer = require('numerizer');
 
 var types = {};
 
+var conversion_regex = /^(.*?)\s([a-zA-Z]+)\sto\s([a-zA-Z]+)$/i;
+
 var db_regex = /[a-zA-Z]+:\n([\s\t]+([a-zA-Z]+,?)+[\s\t]+[0-9.]+[a-zA-Z]+\n)+/g;
 var unit_database = {};
 
+var forms = [/s$/i, /es$/i, /ies$/i];
+
 var parseSection = function(section){
     var lines = section.split('\n');
     var section_name = lines.shift();
@@ -23,12 +28,12 @@ var parseSection = function(section){
 
 	var names = next[0].replace(/[\s\t]/g, '').split(',');
 	var value = next[1].replace(/[\s\t]/g, '').match(/([0-9.]+)|([a-zA-Z]+)/g);
-	var unit = value[1];
+	var unit = value[1].toLowerCase();
 	value = parseFloat(value[0]);
 
 	names.forEach(function(name){
-	    unit_database[section_name][name] = {'unit': unit,
-						 'value': value};
+	    unit_database[section_name][name.toLowerCase()] = {'unit': unit,
+							       'value': value};
 	});
     }
 };
@@ -81,6 +86,26 @@ var convert = function(type, value, from, to, max_calls){
 };
 
 
+var get_variations = function(unit){
+    var variations = [unit];
+    forms.forEach(function(form){
+	if(unit.match(form)){
+	    variations.push(unit.replace(form, ''));
+	}
+    });
+    return variations;
+};
+
+
+var determine_type = function(variations){
+    for(var i in types){
+	for(var k in variations){
+	    if(unit_database[types[i]][variations[k]] !== undefined){
+		return {'type': types[i], 'unit': variations[k]};
+	    }
+	}
+    }
+};
 
 var default_db = path.join(path.dirname(module.filename), 'default.units');
 importDBSync(default_db);
@@ -92,20 +117,43 @@ return module.exports = {
     getDB: function(){
 	return unit_database;
     },
-    convert: function(type, value, from, to){
-	type = type.toLowerCase();
-
-	if(unit_database[type] == undefined){
-	    throw 'Unit group ' + type + ' does not exist';
-	} else if(unit_database[type][from] == undefined){
-	    throw 'Unit ' + from + ' does not belong to unit group ' + type;
-	} else if(unit_database[type][to] == undefined){
-	    throw 'Unit ' + to + ' does not belong to unit group ' + type;
+    convert: function(str){
+	var type, value, from, to, max_tries;
+
+	var parts = conversion_regex.exec(str);
+	if(parts == null){
+	    throw 'Invalid conversion string: "' + str + '", expected "<value> <from_unit> to <to_unit>"';
+	    return;
+	}
+
+	value = parseFloat(numerizer(parts[1]));
+	var from_variations = get_variations(parts[2].toLowerCase());
+	var to_variations = get_variations(parts[3].toLowerCase());
+
+	var from_type = determine_type(from_variations);
+	var to_type = determine_type(to_variations);
+
+	if(!from_type){
+	    throw 'Unknown unit: "' + parts[2] + '"';
+	    return;
 	}
+	if(!to_type){
+	    throw 'Unknown unit: "' + parts[3] + '"';
+	    return;
+	}
+
+	if(from_type.type !== to_type.type){
+	    throw 'Units "' + from_type.unit + '" and "' + to_type.unit + '" do not belong in the same unit group';
+	    return;
+	}
+
+	type = from_type.type;
+	from = from_type.unit;
+	to = to_type.unit;
 
-	var result = convert(type, value, from, to, 5);
+        var result = convert(type, value, from, to, max_tries);
 	if(result == undefined){
-	    throw 'Conversion of ' + from + ' to ' + to + ' was not possible';
+	    throw 'Conversion of "' + from + '" to "' + to + '" was not possible';
 	} else{
 	    return result;
 	}

package.json

@@ -1,6 +1,6 @@
 {
   "name": "node-units",
-  "version": "0.1.0",
+  "version": "0.1.1",
   "description": "Node.JS unit conversion library with customizable units",
   "main": "lib/index.js",
   "directories": {
@@ -21,5 +21,11 @@
     "conversion"
   ],
   "author": "Brett Langdon <brett@blangdon.com> (www.brett.is)",
-  "license": "MIT"
+  "license": "MIT",
+  "dependencies": {
+    "numerizer": "0.0.2"
+  },
+  "devDependencies": {
+    "mocha": "*"
+  }
 }