Compiling REx `a|b'
   1: BRANCH(4)
   2:   EXACT <a>(7)
   4: BRANCH(7)
   5:   EXACT <b>(7)
   7: END(0)
minlen 1

##</code><code>##

Compiling REx `a\x7cb'
   1: EXACT <a|b>(3)
   3: END(0)
anchored `a|b' at 0 (checking anchored isall) minlen 3