$ perl -Dr testRegexen.pl
Compiling REx `(est|\d)'
size 10 Got 84 bytes for offset annotations.
first at 3
   1: OPEN1(3)
   3:   BRANCH(6)
   4:     EXACT <est>(8)
   6:   BRANCH(8)
   7:     DIGIT(8)
   8: CLOSE1(10)
  10: END(0)
minlen 1 
Offsets: [10]
	1[1] 0[0] 1[1] 2[3] 0[0] 5[1] 6[2] 8[1] 0[0] 9[0] 
Compiling REx `(?:est|\d)'
size 7 Got 60 bytes for offset annotations.

   1: BRANCH(4)
   2:   EXACT <est>(7)
   4: BRANCH(6)
   5:   DIGIT(7)
   6: TAIL(7)
   7: END(0)
minlen 1 
Offsets: [7]
	3[1] 4[3] 0[0] 7[1] 8[2] 9[0] 11[0] 
Compiling REx `est|\d'
size 6 Got 52 bytes for offset annotations.

   1: BRANCH(4)
   2:   EXACT <est>(6)
   4: BRANCH(6)
   5:   DIGIT(6)
   6: END(0)
minlen 1 
Offsets: [6]
	0[0] 1[3] 0[0] 4[1] 5[2] 7[0] 
Compiling REx `est'
size 3 Got 28 bytes for offset annotations.
first at 1
rarest char s at 1
   1: EXACT <est>(3)
   3: END(0)
anchored `est' at 0 (checking anchored isall) minlen 3 
Offsets: [3]
	1[3] 0[0] 4[0] 
Compiling REx `\d'
size 2 Got 20 bytes for offset annotations.
first at 1
   1: DIGIT(2)
   2: END(0)
stclass `DIGIT' minlen 1 
Offsets: [2]
	1[2] 3[0] 
Omitting $` $& $' support.

EXECUTING...

$