
Translating regex into VM code:

Regex		VM code
===============================
a	 	Char a
-------------------------------
[H1-H2]		Range H1 H2
-------------------------------
e1e2		e1 code
		e2 code
-------------------------------
e1|e2	 	Defer S1
	   	e1 code
	 	Jump S2
	   S1: e2 code
	   S2:
===============================
e?	 	Defer S1
	    	e code
	   S1:
              -----------
e?+	 	+Defer S1
	    	e code
	   S1:
              -----------
e??	 	Try S1
	    	e code
	   S1:
-------------------------------
e*	   S1:  Defer S2
	    	e code
	 	Jump S1
	   S2:
              -----------
e*+	   S1:  +Defer S2
	    	e code
	 	Jump S1
	   S2:
              -----------
e*?	   S1:  Try S2
	    	e code
	 	Jump S1
	   S2:
-------------------------------

e+	   S1:  e code
	 	Try S1
              -----------
e++	   S1:  e code
	 	+Try S1
              -----------
e+?	   S1:  e code
	 	Defer S1