Added lesson 3 exercise 2

lesson3_parsing/src/exercise2.pegjs

@@ -0,0 +1,9 @@
+start =
+    countrycode
+
+alpha =
+    [a-z]
+
+countrycode =
+    first:alpha second:alpha
+    {return first + second}

lesson3_parsing/test/exercise2test.js

@@ -0,0 +1,32 @@
+var PEG = require("pegjs");
+var expect = require('expect.js');
+var fs = require('fs');
+var grammar;
+
+
+
+var wrapExceptions = function(f) {
+	return function(x) {
+		try {
+			return f(x);
+		}
+		catch(err) {
+			return undefined;
+		}
+	};
+}; 
+
+grammar = fs.readFileSync("src/exercise2.pegjs").toString();
+parser = wrapExceptions(PEG.buildParser(grammar).parse);  
+
+
+describe('Parser Actions', function(){
+	describe('#countrycode', function(){
+	    it('should parse canada', function() {
+	    	expect(parser("ca")).to.eql('ca');
+	    }),
+	    it('should not parse uae', function() {
+	    	expect(parser("uae")).to.be(undefined);
+	    })
+	})
+})