Updated documentation

regex/doc.go

@@ -95,9 +95,25 @@ Numeric ranges:
 
 	<x-y>			Match any number from x to y (inclusive) (x and y must be positive numbers)
 
-# Flags
+# Key Differences with regexp
 
-Flags are used to change the behavior of the engine. None of them are enabled by default. They are passed as variadic arguments to [Compile].
+The engine and the API differ from [regexp] in a number of ways, some of them very subtle.
-The list of flags is provided in the type definition for [ReFlag].
+The key differences are mentioned below.
+
+Greediness:
+
+This engine does not support non-greedy operators. All operators are always greedy in nature, and will try
+to match as much as they can, while still allowing for a successful match. For example, given the regex:
+
+	y*y
+
+The engine will match as many 'y's as it can, while still allowing the trailing 'y' to be matched.
+
+Another, more subtle example is the following regex:
+
+	x|xx
+
+While the stdlib implementation (and most other engines) will prefer matching the first item of the alternation,
+my engine will _always_ go for the longest possible match, regardless of the order of the alternation.
 */
 package regex