Added support for specifying how often a postfixNode is repeated

postfixNode.go

@@ -15,15 +15,20 @@ const (
 	ASSERTION
 )
 
+var INFINITE_REPS int = -1 // Represents infinite reps eg. the end range in {5,}
 // This represents a node in the postfix representation of the expression
 type postfixNode struct {
-	nodetype NodeType
+	nodetype  NodeType
-	contents []rune // Contents of the node - the length of this would only be >1 if the node represents a character class
+	contents  []rune // Contents of the node - the length of this would only be >1 if the node represents a character class
+	startReps int    // How many times the node should be repeated - used with numeric specifiers
+	endReps   int
 }
 
 // Creates a new escaped node - the given character is assumed to have been preceded by a backslash
 func newEscapedNode(c rune) postfixNode {
 	toReturn := postfixNode{}
+	toReturn.startReps = 1
+	toReturn.endReps = 1
 	switch c {
 	case 's': // Whitespace
 		toReturn.nodetype = CHARACTER
@@ -65,6 +70,8 @@ func newPostfixNode(contents ...rune) postfixNode {
 		panic("Empty node.")
 	}
 	to_return := postfixNode{}
+	to_return.startReps = 1
+	to_return.endReps = 1
 	if len(contents) > 1 { // If the node has more than element, it must be a character class - the type must be CHARACTER
 		to_return.nodetype = CHARACTER
 		to_return.contents = contents