Added ability to access array elements, and this[] accessors

mustache-sharp.test/FormatCompilerTester.cs

@@ -528,6 +528,27 @@ public DerivedClass()
             public new T Value { get; set; }
         }
 
+		/// <summary>
+		/// Access array elements and this
+		/// </summary>
+		[TestMethod]
+		public void TestCompile_Access_Arrays_And_This() {
+			FormatCompiler compiler = new FormatCompiler();
+			const string format = @"Hello, {{Array.[0]}} {{O.[1]}} {{O.[Good evening]}}!!!";
+			Generator generator = compiler.Compile(format);
+			string result = generator.Render(new { O = new ThisAccessor(), Array = new string[] { "Element 0", "Element 1" } });
+			Assert.AreEqual("Hello, Element 0 [1]=1 [Good evening]=Good evening!!!", result, "The wrong text was generated.");
+		}
+
+		public class ThisAccessor {
+			public string this[int i] {
+				get { return "[" + i + "]=" + i.ToString(); }
+			}
+
+			public string this[string s] {
+				get { return "[" + s + "]=" + s; }
+			}
+		}
         #endregion
 
         #region Comment

mustache-sharp/FormatCompiler.cs

@@ -152,7 +152,7 @@ private static string getCommentTagRegex()
 
         private static string getKeyRegex()
         {
-            return @"((?<key>" + RegexHelper.CompoundKey + @")(,(?<alignment>(\+|-)?[\d]+))?(:(?<format>.*?))?)";
+            return @"((?<key>@?" + RegexHelper.CompoundKeyOrArrayAccess + @")(,(?<alignment>(\+|-)?[\d]+))?(:(?<format>.*?))?)";
         }
 
         private static string getTagRegex(TagDefinition definition)

mustache-sharp/PropertyDictionary.cs

@@ -16,6 +16,8 @@ internal sealed class PropertyDictionary : IDictionary<string, object>
 
         private readonly object _instance;
         private readonly Dictionary<string, Func<object, object>> _typeCache;
+		private PropertyInfo _intThis;
+		private PropertyInfo _stringThis;
 
         /// <summary>
         /// Initializes a new instance of a PropertyDictionary.
@@ -34,6 +36,8 @@ public PropertyDictionary(object instance)
                 {
                     _typeCache = getCacheType(_instance);
                 }
+				_intThis = _instance.GetType().GetProperty("Item", new Type[] { typeof(int) });
+				_stringThis = _instance.GetType().GetProperty("Item", new Type[] { typeof(string) });
             }
         }
 
@@ -119,6 +123,10 @@ public bool ContainsKey(string key)
             return _typeCache.ContainsKey(key);
         }
 
+		public bool HasIntThis { get { return _intThis != null; } }
+
+		public bool HasStringThis { get { return _stringThis != null; } }
+
         /// <summary>
         /// Gets the name of the properties in the type.
         /// </summary>
@@ -152,7 +160,43 @@ public bool TryGetValue(string key, out object value)
             return true;
         }
 
-        /// <summary>
+ 		/// <summary>
+		/// Tries to get the this[key] value for the given property name.
+		/// </summary>
+		/// <param name="key">The index to use in the this method.</param>
+		/// <param name="value">The variable to store the value of the property or the default value if the property is not found.</param>
+		/// <returns>True if a result was found; false if an exception was thrown.</returns>
+		/// <exception cref="System.ArgumentNullException">The key was null.</exception>
+
+		public bool TryGetThisValue(int key, out object value) {
+			try {
+				value = _intThis.GetValue(_instance, new object[] { key });
+				return true;
+			} catch {
+				value = null;
+				return false;
+			}
+		}
+
+		/// <summary>
+		/// Tries to get the this[key] value for the given property name.
+		/// </summary>
+		/// <param name="key">The index to use in the this method.</param>
+		/// <param name="value">The variable to store the value of the property or the default value if the property is not found.</param>
+		/// <returns>True if a result was found; false if an exception was thrown.</returns>
+		/// <exception cref="System.ArgumentNullException">The key was null.</exception>
+
+		public bool TryGetThisValue(string key, out object value) {
+			try {
+				value = _stringThis.GetValue(_instance, new object[] { key });
+				return true;
+			} catch {
+				value = null;
+				return false;
+			}
+		}
+
+       /// <summary>
         /// Gets the values of all of the properties in the object.
         /// </summary>
         public ICollection<object> Values

mustache-sharp/RegexHelper.cs

@@ -12,7 +12,13 @@ internal static class RegexHelper
         public const string String = @"'.*?'";
         public const string Number = @"[-+]?\d*\.?\d+";
         public const string CompoundKey = "@?" + Key + @"(?:\." + Key + ")*";
-        public const string Argument = @"(?:(?<arg_key>" + CompoundKey + @")|(?<arg_string>" + String + @")|(?<arg_number>" + Number + @"))";
+		public const string KeyOrArrayAccess = "(?:" + Key + @"|\[[^\]]+\]" + ")";
+		public const string CompoundKeyOrArrayAccess = KeyOrArrayAccess + @"(\." + KeyOrArrayAccess + ")*";
+		public const string Argument = @"(?:(?<arg_key>" + CompoundKey + @")|(?<arg_string>" + String + @")|(?<arg_number>" + Number + @"))";
+
+		public static bool IsInteger(string s) {
+			return Regex.IsMatch(s, @"^\d{1,10}$");
+		}
 
         /// <summary>
         /// Determines whether the given name is a legal identifier.
@@ -29,6 +35,16 @@ public static bool IsValidIdentifier(string name)
             return regex.IsMatch(name);
         }
 
+		public static string[] SplitKey(string compoundKey) {
+			MatchCollection m = Regex.Matches(compoundKey, KeyOrArrayAccess);
+			// Would prefer to use Linq for this, but MatchCollection does not seem to support it
+			string[] result = new string[m.Count];
+			for (int i = 0; i < result.Length; i++) {
+				result[i] = m[i].Value;
+			}
+			return result;
+		}
+
         public static bool IsString(string value)
         {
             if (value == null)

mustache-sharp/Scope.cs

@@ -182,7 +182,7 @@ public bool TryFind(string name, out object value)
         private SearchResults tryFind(string name)
         {
             SearchResults results = new SearchResults();
-            results.Members = name.Split('.');
+            results.Members = RegexHelper.SplitKey(name);
             results.MemberIndex = 0;
             if (results.Member == "this")
             {
@@ -199,7 +199,7 @@ private SearchResults tryFind(string name)
                 results.Lookup = toLookup(results.Value);
                 results.MemberIndex = index;
                 object value;
-                results.Found = results.Lookup.TryGetValue(results.Member, out value);
+                results.Found = tryLookup(results, out value);
                 results.Value = value;
             }
             return results;
@@ -209,7 +209,7 @@ private void tryFindFirst(SearchResults results)
         {
             results.Lookup = toLookup(_source);
             object value;
-            if (results.Lookup.TryGetValue(results.Member, out value))
+            if (tryLookup(results, out value))
             {
                 results.Found = true;
                 results.Value = value;
@@ -223,6 +223,31 @@ private void tryFindFirst(SearchResults results)
             }
             _parent.tryFindFirst(results);
         }
+
+		private bool tryLookup(SearchResults results, out object value) {
+			string member = results.Member;
+			if (member.StartsWith("[")) {
+				value = null;
+				PropertyDictionary dic = results.Lookup as PropertyDictionary;
+				if (dic == null) return false;
+				member = member.Substring(1, member.Length - 2);
+				if (RegexHelper.IsInteger(member)) {
+					int i = int.Parse(member);
+					if (dic.HasIntThis) {
+						if (dic.TryGetThisValue(i, out value)) return true;
+					}
+					Array array = dic.Instance as Array;
+					if (array != null && i < array.GetUpperBound(0)) {
+						value = array.GetValue(i);
+						return true;
+					}
+				}
+				if(dic.HasStringThis) return (dic.TryGetThisValue(member, out value));
+				return false;
+			} else {
+				return results.Lookup.TryGetValue(member, out value);
+			}
+		}
     }
 
     internal class SearchResults